Q: My 1999 Corolla's power window froze. I quit trying to work it for a few minutes, and then tried it again. It worked for just a minute, but quit once more. Now, a couple of days later, it is working perfectly. I am afraid to keep opening or closing it, because it might stick.
I try to be handy with things, but I have not seen the inside of a car door. Is it simple enough that I'd be able to fix it if it happens again?
A: It probably quit for a minute when the motor overheated from trying too hard, caused by a misaligned track or a damaged gasket or seal. It worked again for a little bit after the motor cooled off.
Look for something that's causing too much drag. I've seen this problem caused by foreign objects in the track or by sticky soda spilled onto the gasket. If that's it, clean and lube the track.
Q: How important is it to change the brake fluid in your car? My Lexus ES330 service manual calls for it to be replaced at 30,000 miles, and the car is not even two years old. It costs more than $200 at the dealership.
Yet the service manual for my sister's Camry doesn't call for this ever to be done.
A: I checked, and you're right:
I think once every two years is a good interval for replacing brake fluid. Moisture in the system is the problem. Brake fluid that has picked up a few percentage points of water has a lower boiling point, and may fail under heavy usage. I've boiled brake fluid while racing, and it is pretty scary.
The flat-rate manual says that it should take 1.3 hours to bleed the brakes on the ES330. That would mean that, if the shop charged you a flat rate, it's billing you around $150 an hour. It's time to start shopping for a cheaper repair shop.
Q: I have a 2001 Chevrolet Suburban that intermittently cranks but doesn't start. Sometimes it also cuts off when I take my foot off the gas. It always restarts after I let it sit for a few minutes. The car has about 72,000 miles on it, and runs great otherwise.
I bought a scan tool, and it does not show any error codes. Do you have any suggestions?
A: Spend some more time with your new scan tool, and capture a data stream when the car dies or won't start. It's probably called "flight recorder" mode or some such, depending on your scan tool.
This will let you trap 30 seconds of data from the sensors feeding the computer, which in turn will give you a chance to figure out what is causing the stalling and hard-to-start behavior.
Q: I recently bought a 1994 Mazda 626 from a friend. This is my first car, and I would like to learn basic maintenance and some more advanced repairs. I also want to learn how to do some body work.
What are some good resources to learn about this stuff?
A: Try "How-To Central" at popularmechanics.com.
Q: I have a 2005 Chevrolet Impala that has silver paint spots on the finish. Is there some way to remove this paint, other than by taking it to a body shop?
A: You should find some advice at meguiars.com.
Mike Allen is a senior editor for Popular Mechanics magazine. Questions should be e-mailed to driveit@nytimes.com.
