Q: Rough idling - 1990 Chevrolet G30

asked by on September 28, 2016

My van overheated one time. After that, it started to idle rough. This occurs in reverse, park and drive when the engine is still cold. When the engine warms up, there would still be rough idling but only in reverse and drive, whereas it's fine in neutral or park. The van has no trouble accelerating. I checked the tailpipe and there is no resiude or moisture. The oil and coolant are looking good and aren't mixed. The spark plugs are fine as well. What should I do?

This could be an issue with a blown head gasket. This would require a professional mechanic to check engine compression as well. This can occur without causing oil/coolant mixing. If you are still having trouble, a certified technician from YourMechanic can come to your home or office to definitively diagnose the rough idling issue.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

How bad is engine failure for the car, should I get rid of it?

There is really no way of knowing how long an engine will last, but one could expect it to last more than 62,000 miles. GM has been trying to figure out why there is a common failure across many models...

What is a normal sitting at a light coolant temp. Been going up to 218

Normally, the indicator (or pointer) on the engine temperature gauge should be in the "center", or lower. If your cooling gauge has numbers, the acceptable operating range is 195 to 215 degrees. Above or below that range, in normal engine...

Leaking from radiator drain plug petcock.

Hello. The only other solution you may have is to remove the petcock and install a bolt in its place with sealant. I do not recommend doing this though as it is not a permanent fix. If you want to...

Related articles

Signs Your AC Needs to Be Recharged
If you feel the AC is not cooling as much as usual, cannot hear the AC clutch engaging, and see refrigerant leaks, you may have to recharge your AC.
A Buyer’s Guide to the 2012 Chevrolet Silverado
While While the Ford F-150 is still the best-selling pickup truck in the US, the 2012 Chevrolet Silverado is one of the finest half-ton pickups available today. In fact, the Silverado and the GMC Sierra are actually the same vehicle...
A Buyer’s Guide to the 2012 Chevrolet Tahoe
The The Chevy Tahoe has always been one of the most popular SUVs on the market, and this trend continued in 2012. As always, the vehicle proved to be reliable and powerful, with plenty of space and features that people...