A collection of tech tips from past newsletters.  --->   Circle City Corvettes Home

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C5 HVAC control panel lights.

If you have a C5 with a few miles on it, expect your HVAC (heating, ventilation, air conditioning) control display to go blank. Mine did about a year ago. For a while, it would come back if I rapped it smartly, but eventually, it darkened such that I could only read it in the dark garage. Your local mechanic probably wants $300 to $450,  plus labor,  to replace the box. One of our favorite online vendor places wants $300 for the box. On eBay, I've read, you can send it off to somebody who knows the following trick, and will fix it for about $50.

The culprit is a lousy soldering job on the surface-mount components performed by the GM supplier. The components with the "cold" solder connections work loose - sometimes a percussive adjustment applied by knuckle will cause them to make contact again. But, that's tough on the knuckles and the display window.

At our going away party for Marty and Val the other night, I heard Andrew Country discussing a fix for this problem found on the internet. So I checked it out.

First series of steps is removing the box from the dash. Follow the instructions on this link to remove the box:

http://www.vetteessentials.com/instructions/g_bezels/bezel_howto.html

Removal is straight forward; the C5 dash comes apart much like a C4 dash, start at the back of the console and remove things going forward. No need to go past step 3g, as the instructions on this site are for access to the instrument cluster. ( Use them to put the shiny bezel kit on your instruments. )

Here's the link to work on the box, also contains the above link:

http://forums.corvetteforum.com/c5-tech/1583758-c5-climate-control-dim-dark-display-fix.html

Disassemble the box. Be careful with the screws, there's eight of them, all the same size. Find the offending components on the back side of the circuit board in the back half of the box. Don't remove the board from the front half unless you need to replace burnt-out light bulbs or are terribly fond of chinese puzzles.

The offending components are the eight large (1/4 inch), dark-colored surface mount resistors with the number "241" printed on them. Surface mount electronic components have copper band at each; the band solders to the mounting pads on the circuit boards. GM has at least two different layouts for this circuit board, but both have eight of these resistors. If you examine them with a magnifier, you may see a crack at the edge of the solder where the solder should flow smoothly to the mounting pad. Use just enough rosin core solder to make the end of the very hot soldering iron shiny and a little more. Do NOT use plumber's acid core solder! Press down on the center of the resistor with a very small screwdriver or similar implement, then press the tip of the iron to both the end of the resistor and the metal pad on the circuit board. Each heat application should not take over five seconds - we don't want to scorch the board or lift the metal traces from the board. Examine your work, the solder should flow smoothly from the resistor to the pad, except for the lump left behind by this fairly primitive technique. Clean the soldering iron tip in between uses to remove carbonized rosin; but not with your fingers, unless you're really really really into pain.

Reinstall, enjoy. Your mileage may vary - some forum readers botched the job, others simply reported it did not work. It worked on mine, we can see the display in the daylight again - good as new.

Brent Gourley
'93  Z25 / Z07 40th with 190,000 miles
'99  white Z51 coupe with 130,000 miles

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How often should you change the oil in your 'Vette's engine?

                Click here for this month's tech tip. 

George Heneveld

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I promised to report on the experience to changing Run Flat tires to Non-Run Flat tires.

I looked for the best value at many places and checked 4 brands for the price and value. Two brands were foreign tire makers. I don't do business with foreign companies if I can help it. The other two brands were Michelin Tires and B. F. Goodrich. Using the computer and the Tire Rack organization the tires were described in detail how good they were. The appropriate tires in the Michelin Brand started at, with shipping costs, $1,400 dollars. That was ok, but I decided on the B. F. Goodrich tires. The tires were the recommended in 2005 as the best tires to replace the Run Flats. The cost of a set of the B. F. Goodrich was around $900. I ordered them on a Tuesday and they arrived on Thursday and I had them put on at the Enterprise Chevrolet and had my '08 Vette aligned for the amount of $124 dollars.

There are some things that one should know about the tires. They should be broken in for about 500 miles. There is a lining in the tires that has to be smoothed through out the inside of the tire for them to function properly. So no high speeds should have taken place until this is accomplished or bumping may occur while you drive.

There are three great things with the tire that I like. One, they are 100% smother than the Run Flat tires I had on. By the way the old tires were Goodyear Run Flats. The second best thing was the tread. The tread looks great. It is different than I have ever seen before. They are produced not to hydroplane during wet weather. I tested it out 3 times, three different days, three different intensities of rain. The tires performed absolutely great in light, medium, and heavy down pours. The tires did not slip at all while accelerating. I was amazed at the performance. Third, the tire noise of the tires was their only down fall. Between 35 and 45 miles per hour you get some noise. Below the 35 miles per hour no noise. Above 45 miles per hour very little noise. At cruise, you can not hear them. I can live with that because the Goodyear tires were loud all of the time compared to the new B. F. Goodrich that I have on my '08 Vette. I also have new B. F. Goodrich on my '87 Vette and they are great. No noise what so ever.

I hope this is helpful in the decision to change from Run Flats to Non-Run Flats. If you have Non-Run Flats you should purchase a tire repair kit with a portable tire pump. They are very inexpensive and will be well worth it if you have some bad luck with a flat.

I am now your official Tech Tip person and I hope you are pleased with my outpouring of my technical data.

George Heneveld

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For those of you out there with a C5 Corvette and your seat, or seats, slide back and forth a little or a lot. Here is a shim kit advertised to eliminate this problem.

I have purchased this kit, but have not yet installed it. I hope to do it soon and if you can wait I will be glad to tell you if it works or not.

Here is the link to purchasing the kit: http://www.zip-corvette.com/Zip/productr.asp?pf_id=I-2413

Please review this PDF file and decide if you want to attempt it or have someone else do it.

Terry

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Tips for working with extreme Summertime Heat

Extreme temperatures are commonplace here in South Alabama. Here are a couple of good tips for keeping your car in good shape during the hot summers.

Check your Battery: Extreme temperatures are very hard on your battery. The heat will evaporate the battery fluid. Have your electrical system checked and ensure your charging system is working correctly. If you need to add water to your battery, use DISTILLED WATER. Your regular oil change is a perfect time to have this checked.

Check your cooling System: Have your cooling system checked. Change your coolant annually. With Corvettes especially, we do a lot of idling in the Summer heat. A few months of these temperatures has an affect on the coolant in your cooling system. A pressure test is also in order, along with a thermostat test and a cooling fan test.

Check your tires for wear: Check your tire pressure. Summer heat will cause the pressure within your tires to change dramatically throughout the Summer months. Have your tires rotated every 6,000 miles. (check your spare as well!)

With these few simple checks your car will last a long and healthy life.

Stay Cool!

Terry

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Why do airplanes have a service life of forty years or longer and cars don’t? However, cars can, and do, easily run 200,000 miles and more, and 20 years or longer, if given the proper maintenance.

You can run your car to the 200K-mile mark and more by the amounts they can save on labor by doing it yourself. The money saved can buy tools and parts to not only pay for immediate repairs needed, but to implement thorough preventive maintenance as well. For example, go to a repair shop with a bad alternator. You'll probably come out with a bill for $300 or more ($125 for a remanufactured alternator and $75 to diagnose the problem and replace the alternator). You may soon be back with a bad battery, bad alternator or bad drive belt, but those are new repairs ... and they can "nickel and dime" you to death. Each of these problems can leave you stranded with a car that won't start and has to be towed to the shop. A few of these problems will soon have you feeling that your nice new car has turned into a clunker and reached the end of its useful life. You may cast away a good car, even though it only has 80,000 miles on it, and then be saddled with new or larger monthly car payments.

An alternative is to do the repair yourself, and throw in preventive maintenance as well, by rebuilding the whole charging system. You can replace the alternator, voltage regulator, and battery and drive belt for about the same amount of money (assuming you buy the parts at a discount from a discount auto store, mail order firm or online car parts center). Then you can forget the whole charging system for several more years and many tens of thousands of miles.

The key to keeping your car from turning into an unreliable clunker is performing good preventive maintenance. If two tires are worn and two are marginal, replace all four.. If the shocks are getting old, replace all four at once. If the heater and radiator hoses are old, drain the antifreeze and replace all of them at once. When a drive belt gets worn, replace all of them at once. Going for 200K miles, if your engine smokes, rebuild the whole thing. If your transmission slips, rebuild it and throw in a new/remanufactured torque converter. If a front-wheel drive CV joint gets noisy, replace both drive shaft halves, and throw in new wheel bearings while you're at it. When you replace spark plugs, replace the plug wires and distributor cap and rotor at the same time. By rebuilding systems, you'll save money in the long run and keep your car from becoming an unreliable clunker.

And above all, be sure to change your engine oil and filter religiously every five thousand miles (three if your trips are short). If you do this, you might even get 200K miles without an engine rebuild, but if you do have to rebuild the engine you may not have to have your cylinders bored ... a savings of several hundred dollars.

The do-it-yourselfer must be prepared to accept messing up an occasional repair. It's part of the learning process. When this happens, accept your misfortune and do the repair over again, or accept temporary defeat and take your car over to your favorite professional mechanic. Just be polite, be humble, bow your head and admit your failings, hand him the parts in a basket, then shut up and let him do the job. Being diplomatic with a botched job is the mark of the seasoned shade tree mechanic. Even with messing up a job here and there, you'll save money in the long run and be able to afford keeping your car in like-new running condition long after others have hit the bone yard.

Save a bundle of money on labor doing your own repairs, but don't cut corners on tools and parts. You'll watch your neighbors go through three or four cars while you go through one. Then take the money you save on car payments and go buy you a nice Classic Corvette. It'll be a lot of fun to own and drive, it'll turn heads going down the street, and you'll probably sell it for more than you paid for it.

Terry

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Wheel and Tire Care

  Spray-on tire-care products are available from several companies. Most people like the glossy-black look, while other folks prefer the natural semi-gloss black. Many types of common scouring pads can be used to on the white walls/letters. These cleaning pads can also be used to remove the brown brake dust from the sidewalls.

Everyone should be aware that tire failures can be fatal. So, with this in mind, you should visually inspect for sidewall bulges daily along with checking air pressure at every gas stop. Remember, a tire gauge is a lot cheaper than a new set of tires or extensive body work when you blow a tire and run off of the road. The proper tire pressure makes tires last longer, and improves your car's fuel economy. Even when the wheels are properly aligned, under-inflation causes the tires' shoulders to wear faster than the centers, while over-inflation makes the centers go bald before the shoulders. Refer to your owner's manual to find the recommended tire pressure for your vehicle. Also, assuming that the vehicle is aligned properly, even the cheapest tires should last at least 30,000 miles; while expensive brands can exceed 50,000. On the other hand, worn tires may work okay in dry weather, but can become dangerous in even the least amount of rain.

Periodically check the sidewalls for cracking or splitting. Old tires, even with low mileage, can be dangerous because the rubber cracks and hardens over time. This is extremely important with a great deal of those Corvette owners who leave their cars in the garage for long periods of time. Any tire over five years old should be changed. Bottom line: Blowouts can be fatal!

As far as the wheels, these days, almost all new vehicles are factory-equipped with some type of alloy wheels. Some of these wheels have a natural finish, and some have a natural finish with a clear coating and there are some that are powder-coated. Regardless of the type of coating, they will all eventually get covered with disc-brake dust and road film. When you are shopping for the right type of cleaner, it is important to select a cleaner that's designed for the type of wheel you have on your car. For example, clear-coated wheels should be cleaned with a different cleaner than natural-finish alloys or steel wheels. Check with your manufacturer for your specific wheel type and select the proper cleaning product.

Your wheels and tires are a major expense for your Corvette and you should take care of them as well as you do the rest of the car.

Terry

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It is starting to warm up here in South Alabama. Time to be concerned with your car’s cooling system.
Here are a Few Important Things to Remember:

Cooling System consists of:

Pumping -- Your cooling system's pumping function is handled by its water pump, which keeps the coolant mixture moving. The main water pump is gear- or belt-driven but, in many cars, a secondary electric water pump is used for improved flow and cooling. Critical to the pump's operation is the drive belt or gear that turns it. On most newer cars this is the engine's timing belt. On older cars, the pump and belt are external and run off the main crankshaft pulley with a "V" or flat belt. Maintenance of cooling system pumping is limited to scheduled coolant replacement and drive-belt replacement and tension adjustment (external type). Timing-belt-driven pumps should always be replaced at the same time as the timing belt and tensioner.

Piping -- Your cooling system's piping consists of all hoses, any control valves, the heater core, the radiator and the expansion tank. Because of the materials used and the constant contact with coolant, all parts in this system deteriorate more from time than use. Maintenance of cooling system piping consists of scheduled coolant replacement, replacement of all hoses on a regular basis and replacement of any plugged or leaking parts. All hoses should be checked at least twice a year for abrasions, cracks, flexibility and evidence of leakage. Whenever the coolant is drained for replacement or during engine repairs, any suspect hoses should be replaced. All hoses should be replaced at least every few years. Radiators, expansion tanks, heater cores and control valves are normally only replaced due to leakage or plugging. The condition of these parts should be assessed by a professional since proper functioning is critical to many other systems within your car.

Temperature Control -- Your cooling system's temperature controls include all coolant temperature sensors, thermostat, radiator or expansion tank cap, cooling fan(s) and fan clutch (if equipped). These cooling system parts function primarily independent of the engine but control the engine either through cooling or by sending control signals to your car's electronic systems. The thermostat is a spring-loaded valve that opens and closes based on the temperature of the coolant flowing through it. A high temperature reading followed by a drop to normal temperature (or a continuously low temperature) is a common first sign of a sticking thermostat. However, many other conditions may cause these symptoms, so you need to know how to eliminate each possibility. The radiator or expansion tank cap is also a spring-loaded valve reacting to system pressure. It serves to maintain proper system coolant level at predetermined pressures. It must always be replaced with an exact replacement cap with the same pressure setting. Never use other caps except for short-term emergencies! A belt-driven fan blade for pulling air through the radiator is usually on the water pump pulley and should have a fan clutch to control it. The fan clutch allows the fan to turn with the belt at low engine speed and "free-wheel" at higher speeds. A bad fan clutch either doesn't allow the fan to spin at low speed (overheating in traffic) or doesn't allow it to free-wheel at high speed (potential overheating on highway or reduced gas mileage). An electric fan can be either by itself (usually front-wheel drive) or auxiliary (used with a mechanical fan). Both types are controlled via a temperature sensor - in the radiator or upper radiator hose or on the thermostat or water pump housing. This sensor is usually an on/off type switch with a fixed temperature setting. (Some vehicles may have 2-3 settings for multi-speed fans.) This sensor is commonly called an "auxilliary fan switch" Other common temperature sensors are: 1) gauge sender (variable output); 2) warning light sender (on/off type); 3) lambda and/or fuel injection sensor(s) (variable to control fuel injection settings); 4) thermo-time switch (cold start valve control). Your car may have other sensors as well. Temperature control is critical to both performance and emission control. Unfortunately, this system is the most difficult to troubleshoot without proper equipment and diagrams. It's even more difficult with computers that adjust timing, idle speed, vacuum and fuel delivery automatically to make up for potentially faulty temperature sensor signals. Maintenance of your cooling system sensors is virtually impossible since there's nothing really to "maintain". Keeping them clean both internally (coolant replacement) and externally (engine cleaning) is the best way to ensure trouble-free driving. Checking and replacing all parts at the factory-recommended time or mileage limits helps as well.

Tips

Tip #1: Keep your engine and engine compartment, as well as your radiator fins and grill, as clean as possible. A clean engine runs much cooler - and it's much easier to work on.

Tip #2: Replace coolant at or before factory recommended intervals with the proper type, mixture and volume of coolant. Always allow the coolant system to rid itself of air before installing the radiator cap.

Tip #3: Replace all cooling system hoses - upper and lower radiator hoses, bypass hoses, heater hoses, manifold coolant hoses and any other hoses on your vehicle - whenever you even suspect there may be a problem. All hoses should be replaced at least every two years.

Tip #4: Replace the thermostat with the original temperature setting equivalent. The electronics in your vehicle may use that setting for other controls. Do not substitute under any circumstances.

Tip #5: Replace the radiator/expansion tank cap with the original pressure setting and OE-type equivalent. Some aftermarket substitutions do not seal and hold pressure properly on foreign-manufactured cars. Again, don't substitute.

Tip #6: Adjust or replace the water pump drive belt (external) at recommended intervals or more frequently, if required. Check belts whenever you're working on any coolant system components.

Tip #7: Replace your water pump with an OEM/OES pump at the first signs of trouble or when your timing belt and tensioner are replaced. Watch for signs of overheating - you don't want to break down in the hot sun when your water pump fails.

Tip #8: Replace the fan clutch and/or fan blade as needed (if applicable). Your car's temperature gauge is often your best guide as to when your fan clutch needs attention.

Tip #9: Replace temperature sensors as required by diagnosis. Leave troubleshooting of your sensors to experts who have the proper equipment and diagrams.

Tip #10: Keep your entire vehicle properly maintained because of the effect timing, idle speed, exhaust and other systems have on your engine's temperature. Your car's cooling system is designed to function with all other systems operating properly. It cannot make up for a poorly operating or overheating engine condition.

Terry

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I feel one of the best tech tips to give is to put you in contact with the people that know. Here are a few websites that can help you out a great deal in caring for your Corvette.

First, we should use our primary sponsor for expertise when maintaining our Corvettes. That’s what they do…

http://www.solomoncadillac.com/HomePage

Corvette Campaigns and Service Bulletins http://www.corvetteactioncenter.com/bulletin.html

Chevrolet Corvette Recalls http://www.automotive.com/used-cars/recalls/11/chevrolet/corvette/index.html

Corvette Recall and Repairs Information http://www.alldata.com/recall/make/Chevrolet/Corvette.html

They all appear to be alike, however if you will take the time to look them over, you will find one that you understand best and are comfortable using. If you have a favorite reference, please let us know. We will be happy to post their website link to help others.

Terry

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(graphics omitted)

A little Corvette Trivia

Most of these Trivia statements were Technical decisions when they were made. Must have been Tech Tips once upon a time.

Did you know.....

...that the man who named the Corvette, Myron "Scottie" Scott, was Chevy's Chief Photographer? He found the name in the "C" section of the dictionary. It means "a speedy pursuit ship in the British navy." Mr. Scott was inducted into the Corvette Hall of Fame in 2002.

...that the first emblem for the Corvette actually had a U.S. flag in it? But 4 days before the Corvette was introduced, GM Management said they had to remove the flag because it was improper and illegal. So they quickly replaced the U.S. flag with the red Chevrolet bow-tie and fleur-de-lis.

...that the idea for the bow-tie logo came from a piece of Paris hotel wallpaper that GM Founder William Durant took in 1908 and brought back with him? Although his wife says he found the inspiration from an Ad in a Virginia newspaper in 1912. Maybe the "Coalettes Ad of 1911 that also used the same bowtie?

...that when Bill Mitchell named the Corvette the "Sting Ray," Zora-Arkus Duntov said "It's a dumb fish!" I don't know if the fish is dumb or not, but sales increased by 50% that year to over 20,000 for the first time (and never went below 20,000 again)! So the idea must have been pretty smart.

...that only 199 buyers chose the Z06 Stingray performance option package in 1963 when it was first offered? It was the namesake for the 2001 Z06. Today it is estimated there are between 80 and 100 1963 Z06 cars remaining and the value of these cars has gone from the purchase price near $6,000 to the six-figure mark!

...that GM was thinking of adding a back seat to the Corvette around 1966? Yup. They were going to make it 10" longer to add a back seat. But when they had to remove the front seat to get Jack Gordon (the President at the time) out of the back seat of the prototype, that killed that idea. Here's my own "prototype" of what it would have looked like!

...that only 20 L88's Corvettes were built in 1967 when it was first introduced? Chevrolet rated the L-88 at only 430hp, but the actual output was estimated upwards of 550hp. Note: These are the cars that can fetch $600,000 or more in auction today (where's my checkbook?).

...that 1982 was the last year for both the 8-track player and CB radio option?

...that there is actually two 1983 corvettes? The official one was the last survivor when the initial 43 1983's were produced, which now lives in the National Corvette Museum. However, they didn't finish "building" it until 5 years later.

The other 1983 was won in a National Council of Corvette Clubs charity raffle and is now owned by Dick Goyner. It was raffled as the first 1984 (with the only "Serial Number 00001" from any generation of Corvette known to still exist). There were 70 test vehicles built first with VIN's 00002-0071, then the 71st car built was given the VIN 0001. Mr. Goyner still has this car's original Build Sheet dated December 16, 1982. So it has been confirmed that he actually has a 1983 assigned vin0001 for 1984!

...that the last C4 (owned by Mid-America Design's Mike Yager) was signed by each Bowling Green, KY plant worker as it was being assembled down the line on June 20, 1996? That's a LOT of autographs on one car! It was the 358,180th C4 corvette, an Arctic White LT1 coupe with special accents. Mike even got to help put it together.

This month’s tips are from

Corvettes of Charlotte County
Port Charlotte, Florida

Hope you enjoyed them!

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Jan 09 Tech Tip

New Years Resolutions

We all usually make New Year’s resolutions for ourselves, but what about our Corvettes?  Try something like these this year.

Myself – Get some of this extra weight off and try to keep it off.

My Corvette – Get it cleaned out and try to keep it clean.

Myself – Exercise more and try to stay fit.

My Corvette – Exercise it more and try to NOT get a ticket.

Myself – Try to enjoy life more this year.

My Corvette – Try to attend more Club activities this year

Myself – Try to appreciate others more.

My Corvette – Try to appreciate other Corvettes, even though yours is “nicer”

Myself – Be friendlier to others.

My Corvette – SAVE THE WAVE!

Have a Great New Year – 2009

Terry

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Improve your gas mileage

Every little bit helps

Drive Sensibly - Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town. Sensible driving is also safer for you and others, so you may save more than gas money.

 Observe the Speed Limit - While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph. You can assume that each 5 mph you drive over 60 mph is like paying an additional $0.24 per gallon for gas. Observing the speed limit is also safer.

Remove Excess Weight - Avoid keeping unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your MPG by up to 2%. The reduction is based on the percentage of extra weight relative to the vehicle's weight and affects smaller vehicles more than larger ones.

 Avoid Excessive Idling - Idling gets 0 miles per gallon. Cars with larger engines typically waste more gas at idle than do cars with smaller engines.

 Use Cruise Control - Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.

 Use Overdrive Gears - When you use overdrive gearing, your car's engine speed goes down. This saves gas and reduces engine wear.  My 1998 Corvette runs 1800 rpms at 68 mph, if I speed up to 70 mph, my rpm increases to 2100 rpm. I think Corvettes are geared perfectly for highway traveling.

Figures based on $3.84 per gal.

Terry

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WAX ON  - WAX OFF

Do colored waxes really work?

First, there is no way that a limited selection of 8-12 different-colored waxes can even begin to match the many different hues inherent in the particular color of your car.  Second, most cars being manufactured today, and in the last 10 years have a clear coat finish. This top, clear layer of paint does not contain any color pigments, therefore, it doesn't make any sense to apply a colored wax on top of a paint that is clear. To do so would be to temporarily cloud, or discolor the original color coat that is underneath your clear coat. You are creating an unnatural effect that will look even stranger as the pigments in the wax fade.

If your goal is to have a great looking finish, then it makes more sense to spend your time and effort up front performing good surface prep. Good surface prep is key to all great looking finishes.

Surface Prep with a Clay bar

Removing surface bonded contaminants and restoring a smooth surface to your paint finish is easily accomplished by using a Clay bar. A non-abrasive clay bar safely, easily and instantly removes bonded contaminants as you rub it across the surface of your car using a mist & wipe product. A Clay bar contains everything you need to create a smooth surface! So purchase a Clay Kit which includes: clay bars, individually wrapped & in a moisture-seal case, a detailer for use as a clay lubricant, Cleaner Wax sample & a couple of Microfiber Towels.
Here's Jay Leno on the Maguiar's website:  http://tinyurl.com/485uk6.

There are two basic reasons we wax our cars, protection or beauty.

Protection.  If your looking for the maximum protection, one or two, or, maybe even up to three thin coats of wax, has the potential to create the most surface protection depending on the wax, the surface itself, and whether or not sufficient time has passed in-between each application. Of course the law of diminishing returns states that you will not create greater layers of protection with each application, but a second, and sometimes third application will insure uniform, thorough coverage over the majority of the surface, thus maximizing the protection.
Environmental conditions demand more frequent washing and waxing in order to prevent costly damage to the outer layers of paint. It is also vitally important that you wax more often to maintain your finish. This is especially true if your car is a daily driver exposed to the elements and parked outdoors most of the time.

Beauty.  Generally speaking, when trying to take your car's finish to its maximum potential for clarity, gloss, shine and depth of color, there comes a point that you will reach whereupon additional applications of either polish or wax will not increase the results of any of those categories. Of course, you are more apt to reach this plateau if your skill level is high and if the quality of your products is also very high.

Terry

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Let’s talk brakes

SQUEALERS

If you have a squeal or squeak from your brakes that won’t go away and you've tried everything to stop it, give this a try: Remove the pads and clean the dirt and dust from the back side. Use any brake cleaner because they all works just fine. Brake cleaner dries fast and does not leave a film. After you’ve cleaned it thoroughly, spray or brush on a good coating of disc-brake anti-squeal compound on the back of the pads (can be found in most auto part stores). Let it to dry for at least a half an hour. After it is dry, replace the pads and anti-squeal shims (if used on your car). The squeaks and squeals hold not return a couple of years.

DULL DRUMS

Plenty of vintage Corvettes are equipped with drum brakes (actually, everything prior to '65, and even a few '65 models), and for the most part, servicing these components is pretty much a no-brainer. One thing to remember, however, is that when you replace the shoes, use a bit of Scotch-Brite to clean the contact points on the wheel backing plates. Next, lube these contact points lightly with white grease. This allows for smooth shoe action. Just be careful not to drop any grease on the shoes. If you do, use some spray-on brake cleaner to clean it. Otherwise, the friction material won't be too happy!

TURKEY BASTER TIME

If you're encountering a tough brake bleeding operation on one or more of your Corvette calipers, try this: A turkey baster can be used to pump brake fluid into the bleed screw to force the bubbles out of their hiding places.

Terry

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Tire pressure - How much is enough?? With the added interest in fuel economy, you are hearing more about keeping your tires properly inflated to save gas. And according to the Democratic Presidential nominee, if we all properly inflated our tires, the greatly increased fuel mileage would lower demand, and therefore lower gas prices. Well I'm sorry, but fully inflating our tires isn't going to solve our energy problems. In a worst case scenario, you may pick up 2 or maybe 3 miles per gallon, but that if only if you are running around with your tires Significantly deflated. In most cases, you may get a 1 mile per gallon improvement. But hey, a 1 mile per gallon improvement is better than a poke in the eye with a sharp stick!! What about overinflating the tires, you know, 'if a little is good a lot is better' kind of thinking. Well the problem with over-inflating is pre-mature wear out of the center of the tire tread. An overinflated tire will bulge out in the middle and so this center area of the tread will be carrying most of the weight of the car and therefore take most of the wear. So, when our Corvette tires cost $500 to over $1000 for a set of tires, wearing them out early pretty well washes away any savings from the improved gas mileage. So back to the original question - how much air? The first place to look is the manufactures recommendations which can be found on a sticker on the door jam of the drivers door. For C5's and C6's the recommendation is 30 front and 30 rear, when Cold. Most have discovered that 30 is too much for the rear tires if you want even tire wear. With the low tire pressure warning going off at <25 lbs, unless you want that annoying alert every time you start the car, 25 would be your minimum. I have found 27-28 works pretty good for both my C5's, and according to what I have read on Corvette forum, this works for C6's also. For the front, I have found I can bump the pressure up a few pounds and still get even tire wear, so I run 33-35 lbs in the front. And again according to the posts on Corvette forum, well, the jury is still out. Several recommend only 28 up front for even tire wear, and others 32. So, maybe start with 30 and check the tread wear every month or so and adjust accordingly. But another variable for front tire wear is driving style. If you are the type that enjoy "taking a curve" whenever the opportunity presents itself, than you will be getting more wear on the tire shoulders. So if you are in this group, than maybe 33-35 up front would work for you too.

Bruce

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  If you have been listening to some of the automotive forums lately, there has been a lot of buzz about the recent government mandated motor oil reformulation. It seems that some pencil pushing bureaucrat decided we needed to get the zinc and phosphorous out of motor oil cause it was damaging catalytic converters. What’s the big deal, well, the additive ZDDP (zinc-dialkyl-dithiophosphate) that is added to motor oil is an extreme pressure antiwear additive. With the lower levels of ZDDP now in most off the shelf oil, wear on those motor parts that side against each other while under pressure can suffer greatly increased levels of wear. So, which engine parts do this? The cam and lifters do, but ONLY if the lifters are the flat tappet type, rather than roller tappets. For Vettes, our engine have had roller lifters since ’87, and rollers were pretty much industry wide by the mid 90’s. And really, the primary area of concern for the flat tappet motors is during the initial break-in period. The first 300-500 miles are critical and during this time absolutely need an oil containing a significant amount of ZDDP, or use an oil additive containing ZDDP. Once the engine is broken in, it would be a good idea to be selective on the choice of oil, especially if the engine has high load valve springs. If you want to use Mobil 1, their 0-40 “For European Cars” formula would be a good choice, or the Mobil 1 high mileage 10-40. These both have 1000ppm of ZDDP, as opposed to 800ppm for other Mobil 1 oils. Or you can spend a little more and get a ‘true’ synthetic oil that provides roughly 4 times the protection of Mobil 1. These oils include Red Line, Royal Purple, and Amsoil.

It really tic’s me off that the feds are screwing with our motor oils, as the difference the reduced levels of ZDDP will make to the life of a catalytic converter is very, very little. Its just our ‘big brother’ watching out for us!!

Bruce

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The following article is re-printed from Greencar.com

The 3,000 Mile Oil Change Myth

According to a recent study by the California Integrated Waste Management Board, 73 percent of California drivers change their oil more frequently than required. This same scenario no doubt repeats itself across the country. Besides wasting money, this translates into unnecessary consumption of $100-a-barrel oil, much of it imported. Using 2005 data, the Board estimates that Californians alone generate about 153.5 million gallons of waste oil annually, of which only about 60 percent is recycled. Used motor oil poses the greatest environmental risk of all automotive fluids because it is insoluble, persistent, and contains heavy metal and toxic chemicals. One gallon of used oil can foul the taste of one million gallons of water. It’s been a misconception for years that engine oil should be changed every 3000 miles, even though most auto manufacturers now recommend oil changes at 5,000, 7,000, or even 10,000 mile intervals under normal driving conditions. Greatly improved oils, including synthetic oils, coupled with better engines mean longer spans between oil changes without harming an engine. The 3000 mile interval is a carryover from days when engines used single-grade, non-detergent oils. For several years, automakers like General Motors, BMW, and Mercedes Benz installed computerized systems that alert drivers via an instrument panel light when it’s time to change oil. As an example, the General Motor Oil Life System (GMOLS) analyzes the engine temperature, rpms, vehicle speeds, and other driving conditions to calculate the rate of engine oil degradation. Then, software calculates when the oil needs to be changed. Other systems work similarly .Because of the many external conditions and parameters that have to be taken into account, calculating the precise maximum service interval using mathematical models alone is difficult. Now, Daimler AG has developed a more direct and precise way to monitor oil quality directly on board a vehicle. Daimler uses a special sensor integrated into the oil circuit to monitor engine oil directly. Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change. Daimler uses the oil’s “permittivity,” that is, the ability to polarize in response to the electric field. If the engine oil is contaminated by water or soot particles, it polarizes to a greater extent and its permittivity increases. To evaluate the quality of the oil, permittivity is measured by applying an AC potential between the interior and exterior pipes of an oil-filled sensor to determine how well the oil transmits the applied electric field. Because not all impurities can be measured with sufficient precision via the electric field method, Daimler also measures the oil’s viscosity to detect any fuel that may have seeped into the oil. Daimler researchers measure viscosity while the vehicle is in motion by observing the oil's side-to-side motion in the oil sump. The slower the oil moves, the higher its viscosity. This movement is registered by a sensor and the viscosity is calculated on this basis. A single sensor, along with the information already monitored by on-board computers, is sufficient to determine the various parameters of the engine oil. Daimler will likely use the technology first on its commercial vehicles. Here, large oil reservoirs mean larger quantities of oil can be saved. Plus, a predicted 25 percent increase between service intervals and reduced downtime will be of interest to fleets, and thus justify the added cost of installation.

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None published - tech tip editor recovering from a long-ish trip.

      As we get ready for Caravan ’08, maybe it’s time to give the ‘ol Vette a bit of a look over before we head out on our annual beach adventure.  Ok, there’s the obvious stuff like checking the engine oil level and tire pressures, but how about the level of the coolant, the brake fluid, and power steering fluid.   And it wouldn’t hurt to check the windshield washer fluid level too.   Then take a minute to look under the car to see if any oil spots are on the floor, especially under the rear of the car where the transmission and differential are (C5’s and 6’s), as these fluid levels rarely get checked.  Finally get all those items in the car that are so easy to forget, like the hand held 2-way radio, your favorite hat, and maybe a few tools.  Then – its FUN time!

 Bruce

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   Most who buy a Corvette are into the performance of the car.  But as the old goes:  “more is better”, explains why millions of dollars are spent by Corvette owners in search of MORE POWER.  But what about those claims you see in the ads, 25 more horsepower from this gismo, and 45 more for that, are they true?  The only way to tell for sure is to have the car dynoed before and after the modification.  I was looking through some old issues of one of my favorite car magazines a few days ago and noticed some interesting articles on a C6 build-up.  The magazine is “GM High-Tech Performance”, and it deals mostly with the LS family of engines that have been powering the Vette since ’97.  The article detailed the modifications to a manual tranny ‘06 Vette, and had dyno results after each modification.  The work and dyno testing was done at East Cost Supercharging, a highly respected performance shop.  They started with the car putting out a baseline of 346 rear wheel horsepower (RWHP) when stock,  which is typical of a manual C6.  Those with the 6-speed auto will put out around 325 due to the additional parasitic drag of the auto tranny.  The first mod was a typical one for most folks - replace the exhaust system, as this adds not only power but that really cool ‘power sound’.  They chose to replace mid pipes and the mufflers with a 3” Corsa system.  This included an X pipe crossover and a 2 outlet muffler system.   Surprisingly, they picked up 13 RWHP!  Not bad at all!  Next was the air intake system.  They went for the system that is without a doubt the most aggressive system available – the Vararam system.  This system not only replaces the stock air box and filter with high flow units, but it incorporates a highly efficient air ducting system that opens at the front of the car (where the air pressure is highest while at highway speeds), thus providing a “ram air” effect.  The only way to verify the benefits of the ram air is on the drag strip, as the car must be moving forward at high speed for this system to work.  Well sports fans it does.   On the dyno, the benefit of the high flow air box and filter added a whopping 3 RWHP, which says the stock system flows pretty well.  But on the drag strip, it picked up 3 mph, which equates to roughly 30 HP!  So the ram air thing is for real!  Next was headers.  They went for a set of long tubes from American Racing Headers which included high flow CAT’s.  This one was a surprise, and in the ‘dollar to HP gained’ department a huge disappointment – only 11 more HP!  Apparently the stock C6 exhaust manifolds flow pretty well.  So maybe it needed tuning.  Well this was another surprise – only a 5 HP gain.  So, after spending about $4100, the dyno gain is only 33 RWHP, but if you factor in the ram air benefit of the Vararam (when at speed), they got a 60 HP increase.  Now all of these mods except for the tuning are changes most folks can do at home, so that’s a plus.  Also, with the headers and the cat back exhaust system, the car now sounds really cool.  After these mods, the next area to attack would be internal engine modifications such as replacing the cam and/or cylinder heads, or maybe a blower.  So, its up to you, and your budget!

Bruce

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Windshield wipers – So, when those wipers don’t clean as well as they used to, have you tired to replace just the wiper insert  rather then the entire wiper blade like most folks do?  Just replacing the insert (the rubber portion) will save you about $10-$20 every time you change you wipers.  To do this on “virgin blades” (OEM blades that are untouched), you will have to do a little bending of the small metal tabs on one end of the original wiper blade so you can remove the old insert.  Sliding the new one on is pretty easy.  Then once on, rather than re-bending the tabs back over, replacement inserts come with locking clips.  This will make future insert changes much easier.  You should remove the blade from the wiper arm to do this procedure and here’s a tip, be sure to get a good look at how the blade attaches to the arm before you remove it.  I recall a time or two when I didn’t pay attention to this it took me several frustrating minutes to get it correctly re-installed.  And here’s one more ‘glass tip’ – if you want your glass top to look as shinny as you freshly waxed car, just spray and wipe with some instant detailer.  It will clean the glass and leave a nice shiney finish.  I use Zano instant detailer on all the exterior glass including the windshield – it works great!

Bruce

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