Questions and Answers

Volkswagen Jetta Rough Idle Q. Vince, My daughter's jetta has been in the shop twice for rough idle and no one can seem to solve the problem. 1995 Volkswagen Jetta Celebration Edition, 2.0 litre, A/C, cruise, looks like a carburetor, not FI, but I could be wrong. Symptom: Car idles fine until warm, 160°, even with the air conditioning on.

After it is warm the idle with the air conditioning on is less than 700 rpm and very rough. Warm with the air off it is 750, okay but still rough. I have replaced the ECM, and had the car tuned but the rough idle problem still remains.

Any help would be appreciated.
Mark

A. The 2.0 liter SOHC engine had a habit of swallowing engine oil through the air induction system. So I would suggest inspecting the intake air supply system (Air Cleaner housing, Mass Air Flow (MAF) sensor housing, and intake air boot) for excessive oil accumulation. I would also give the throttle body a good cleaning as well. I think this will fix the idle problem.