Q: I have a question about the timing belt in my 2007 Toyota Corolla with the four-cylinder, 1.8-liter engine. I can’t find the scheduled time to change the timing belt. Do you have any idea where I can find this, or even, do you know when I should do this?
A: After going through the ALLDATA information system, I can assure you that a timing belt is not present in your car. Your car has what is called a chained engine. The crank-to-cam-shaft timing is controlled by a chain, which is about the size of a standard bicycle chain. There is not any scheduled maintenance on the chain. A vehicle that has regular oil changes and is maintained by the manufacturer’s schedule should most likely never need a chain replacement.
Q: Since the weather is getting colder, my 2003 Chevy Trailblazer is driving very poorly first thing in the morning. I am getting a reduced-power warning light, and the check engine light is on. I have replaced the throttle body assembly in the hopes this would resolve the problems because of the codes stored. Strangely after 15 minutes of driving, I turn off the engine and restart it, and all is well again. The reduced-power light is out, and the check engine light is out. This problem is so intermittent and only happens when it’s close to freezing temperatures, so I don’t know where to begin. Also, I don’t know if a repair shop will be able to catch it while it’s happening. Any advice you can give me will be appreciated. Also, I need a state inspection next month, so I am short on time.
A: This issue you’re having sounds like a GM problem I haven’t seen for a few years. Your computer, which is located in the engine bay, is having internal issues. This was a huge problem in the late ’80s to mid-’90s with GM cars and the first-generation computer. As the temperatures went down, the printed circuit board and the cases they lived in would change size ever so slightly. But, the change was enough for a lack of connection to a few of the many contacts inside of the vehicle computer. Therefore, the computer would send out a very poor signal, if any at all, to the engine. Your vehicle has the computer in the engine bay on the right side. As the engine warms up, so does the environment that the computer lives in. This puts the computer back in a situation where full contact is being made. So, you turn off your engine, restart it, and suddenly, all the problems are gone. A computer replacement with programming is the cure for this problem after you have the diagnostics performed. Expect to spend around $1,200 to make the repairs.