1993 Volkswagen Jetta White Smoke

Suggested Repair

If the previous engine failed, residual coolant may be trapped in the catalytic converter. Drive the car on the highway under load for a while and check whether the white smoke clears.

Conversation Summary

The owner of a 1993 Jetta reports white smoke at idle once the engine is warm, plus an emissions-test failure, but no coolant loss. The ECU, coolant temperature sensor, oxygen sensor, catalytic converter, and muffler have already been replaced. The car was bought from a wrecker, and the smoke was not noticed before the new exhaust parts were installed. The expert said a failed previous engine could have left the catalytic converter full of coolant and recommended a sustained highway drive under load to see if the smoke goes away.