Will changing the air intake and exhaust help the performance and
mileage or just make it sound good? Specifically I was wondering if the cost would be paid back in a year or two by mileage improvement?
Thanks.
Paul Read More

Sure do! There are several possibilities but the two most common that we experience here in the shop are control module and air blend door motor. The system uses various sensors outside and inside the car to tell the module what commands to send out to blend motors that control how hot or cold each side of the car will be.

As the sensors send signals the module which is actually a small computer analyzes them and decides based on internal programming how to set the air blend doors. Air blend doors control how much air passes through the heater core and how much air passes through the AC evaporator. Of course more air through the heater core means hotter air coming into the car and more air through the evaporator means colder air. Read More

Well, I have another puzzling issue with a 1992 Corvette base coupe with 80,000 miles.

The LCD display for the speedometer started to fade a few years ago and although it still displayed the mph, it was getting hard to see. I procured a replacement LCD display and carefully installed it. Afterwards, the LCD was bright and clear for a couple of months without issue. Read More

Question: I want to replace the front coil springs and understand there are no factory replacements available, only after market springs. I also understand that it’s a real crap shoot on how those aftermarket springs will make the car sit. Ride height is critical to me as I want the car to sit dead level and was told things like engine size, options etc… can all affect ride height with the aftermarket springs. Do you know of an aftermarket spring that will give as close as possible correct ride height? 

Guess what? You’re in luck because it isn’t that difficult. Simply go to one of the major Corvette aftermarket suppliers and look up springs for your car. You should find 2 listings: one for big block and one for small block. Buy your small block springs and install them. The front end will likely sit higher for a few weeks until the sprigs break-in and settle to a normal ride height. Once they have settled don’t be surprised if the front is still higher than the back. After all you have two new front springs and a used saggy rear spring.

At this point you can do one of two things: install a new rear spring and adjustable spring hanger bolts or install adjustable rear spring hanger bolts and adjust the car until it’s level. Due to normal variances in springs in general this is the best way we have found in the shop to precisely level a Corvette. Actually back when your car was new because GM was notoriously bad about the quality of their OEM springs we often had to level brand new or nearly new Vettes.

Q. My neighbor tells me that her 1996 Vette’s a/c does not work after starting the vehicle. After driving for awhile the a/c starts working, what could be the problem. Thanks. B.

Pat says. Begin by checking the level of refrigerant in the AC system. When refrigerant is borderline low it may not have enough pressure when cold to trip the pressure switch to allow the system to work. Then as the car is driven engine heat warms the refrigerant, the refrigerant expands and the pressure increases. Now with warmer refrigerant there is enough pressure to close the low pressure switch and on comes the AC.

Actually no! The major difference between cylinder heads for engines designed for leaded and no lead fuel is valve seat hardness. To make a proper no-lead fuel engine the valve seats must be hardened to resist recession. This did not universally happen at GM until 1973.

If you think about it valve seats take a real beating in all engines. As the valves are pulled shut by the valve springs they bang against the valve seats. To visualize this, strike the anvil portion of your bench vise with a steel hammer. You will hear a distinct metal on metal ringing sound as the hammer hits the vise and you will see a tiny dent in the anvil where the hammer struck. For comparison take an old lead wheel weight and position it on top of the spot where you hit your vise and hit the lead weight with the same hammer. This time you’ll hear a dull thud rather than a metal on metal clang. This time there will be no dent in the vise either. Read More

Weather turns and tires

No matter where you live this could be the El Nino winter for the history books. North south east and west the weather people are calling for more snow, more rain and colder temperatures. Of course not all conditions for everyone but probably something not nice and possibly dangerous for just about every part of the country. So now would be the time to prepare for what lies ahead. Even though it may not materialize for some or all of us in my world it is far better to be prepared and not need it than not be prepared and need it.

So let’s start with one of the most important parts of cars when the weather turns; tires! What you need for tires will depend on the type of weather you get where you live. If you get snow or even a lot of days where the temperature is at freezing or below you probably need winter tires. Yes the temperature is as important as snow and ice because temperature causes huge changes in the way tires grip the pavement. So if you call winter tires “snow tires”, don’t. They aren’t snow tires, they are winter tires and they are designed to do a lot more than help you get moving in snow. The other thing with winter tires is they may be highly beneficial even where there is zero snowfall. The rubber in tires is a complex concoction of rubber and other chemicals blended to make the tire grip, wear well, shed water, ride smooth, etc. But no one tire can do everything the best so most tires are designed to do all things in a middling manner. Not great at anything and usually not terrible at anything except cold weather traction. Read More

Winter storage for your car

The days are getting grayer, the hours of sunlight are waning and that means it’s getting closer to time to give our toys a rest. A long winter’s nap as it were. If you have a car you don’t drive in the winter it will soon be time to prep it for its nap.

There are two types of winter storage: first is where you still drive the car on nice days and second where you don’t drive it at all until spring. If you simply don’t drive the car as much things are much simpler. Begin by keeping the fuel tank full and treating the fuel with a stabilizer like Sta Bil, Stor and Start or similar products. We like BG Products Ethanol Defender kit. Good places to find many of your storage products are marine and farm supply stores as both are involved with seasonal equipment. Read More

These showing what a technician has to do to replace the A/C Evaporator.

This vehicle was a 2007  Dodge Magnum RT.

Smooth Ride

Complaints about cars shaking at speed have increased ten- fold in the last few years mostly due to new suspension designs. Today tires wheels and suspensions are designed to work as an integrated system. But this only works when tire and wheel assemblies are perfectly round and roll smoothly. So tires must be properly balanced and must not have excessive rolling resistance. If a tire has a hard spot in its tread it will never roll smoothly no matter how many times it’s balanced.

The secret to making a tire roll smoothly is offsetting the imperfections in the tire to the imperfections in the wheel using a process called match mounting. Never heard of it? Neither have many technicians. Match mounting involves rotating the tire on the wheel so the high or heavy spot of the tire is matched to the low or light spot of the wheel. This requires a balancing machine that measures these factors and checks for stiff spots in the tire’s tread. The machine tells the technician how to rotate the tire around the wheel for smoothest ride.

So before spending money on an old-school run-of- the-mill wheel-balancing job remember you’ll get a smoother ride if you seek out a high-tech hunter road force balancer.

Stay tuned we’ll be right back.

Clean Cars

You’ll feel better about driving a clean car plus good looking cars are always worth more money. Part of what makes a car feel old is the general layer of crud that builds up over time. Let the car go too long and it may be nearly impossible to make it look good again. It’s fun to watch someone as they see their cruddy car for the first time after it has been detailed. Some drivers don’t even recognize their own car because it looks so different cleaned up. Read More