Question:
I recently purchased a new black '09 coupe with the navigation system. I was planning to have the windows tinted, but then I saw the following passage in the Navigation System Manual:

"Notice: Do not apply aftermarket glass tinting to the vehicle's windows. Glass tinting interferes with the system's ability to receive GPS signals and causes the system to malfunction. The window might have to be replaced to correct the problem. This would not be covered by warranty."

The problem is that I live in Arizona, and it gets very hot. Is there any tint I can use on my Corvette?
Sandi
Phoenix, AZ

Answer:
The majority of window tints on the market contain a metallic film, which can interfere with radio-wave signals and cause problems with several onboard systems. These include the following:

TPMS (Tire Pressure Monitoring System): A warning lamp may illuminate on the instrument panel.

Keyless-entry system: The fob may malfunction. (Remember, the C5 and C6 keyless-entry systems share a receiver with the TPMS.)

Navigation system or satellite radio: The tint may interfere with your GPS signal. This is usually only a problem when all of the windows are tinted, along with the top strip on the windshield.

Radio: You may hear static or encounter poor reception. This seems to be more of a problem on the Malibu and Impala than it is on the Corvette.

Cell phone: You may experience poor reception or dropped calls while in your car.

That's the bad news. The good news is that there are several non-metallic films on the market, usually made from ceramic or high-quality polyester. Ceramic films are not only compatible with automotive electronics, but they can block almost three times as much heat as their metallic and polyester counterparts as well. The ceramic films do cost a little more, but they're well worth the price.

Question:
I own a '77 Corvette that's almost completely stock. I recently performed a cooling-system flush and installed straight antifreeze. Since then, I've noticed that the coolant temperature reads around 225 degrees. The temperature gauge has always read about 200 in the summer. What do you think has happened? Is this something I caused when I flushed the coolant? Help!
Connor
Via the Internet

Answer:
It sounds like you made the same mistake a lot of other DIY'ers do. The fact is that a high concentration of antifreeze does not transfer heat as well as pure water or a 50/50 mix of antifreeze and water. This could be a significant contributor to your high coolant temperature. The solution to your problem is to drain the antifreeze and go with a 50/50 mix; this should help the engine run cooler.

After you've confirmed that the correct mixture of antifreeze has resolved your overheating problem, use a hydrometer or a refractometer to confirm that the concentration of coolant will protect your engine during the winter months. Good luck, and let me know how it works out.