QuestionI have a 1993 Corolla wagon, EFI engine, just purchased at an auction, with an automatic transmission. When the engine is cold, it sounds terrible, with a rough idle. The car accelerates and runs OK. Once the engine is warm, the rough idle goes away, but it does seem to occassionally miss (once or twice a minute).
I replaced the spark plugs, but the wires look new so I didn't replace them. The car appears to have been well maintained, without any rust. I found some maintenance records, which shows regular oil changes. The previous owner even replaced the tires recently. The car has 171,000 miles. What else might be causing this?
AnswerA rough idle can be caused by an engine misfire or a bad motor mount, I'm not sure which it is from your description, is there a harsh vibration that can be felt in the steering wheel? If so, it's a motor mount problem.
If it's an engine misfire it's not a vibration but rather a jerky type of feeling felt in the chassis. Since the tune up parts were already replaced I suspect that it is a motor mount problem especially if there is a noise also, most cars bought at auctions are there because of one problem or another and this one may have been involved in an accident and even have some form of frame or crossmember damage, I recommend that you have a professional at a toyota dealer take a look for those possibilities.
