Idling Question

When my car idles in park or at a stop sign the rpms jump and sometimes engine sputters. Hasnt stalled out yet. I have a 2003 monte carlo and 3.4L engine. 87,000 miles never had a tune up. Thanks.

It is time for a tune up. Chevrolet says the spark plugs should last 100,000 miles. They don't. They start to wear out at about 80,000 miles. You probably need new coil packs as well. If you have never changed the serpentine drive belt, add that to the list. Check and see if the PCV is misting oil around the valve chamber. If it is passing oil then the vacume has been compromised and the valve just needs to be replaced. It is a $24.00 fix for the kit. A worn out PCV can cause idling issues similar to yours.

awesome man thanks for the heads up on that.

just curious why reccomend coil packs on a tune up? plugs and wires of course, but if coil towers are not corroded and spark is good, why spend the $ if not needed? Seriously asking here, knowledge is key!

The coil packs are more something to check and see if they are working properly. In the case of Legacy3135 it would not be a bad idea to have them checked since there is 87,000 miles on the engine. One of the packs could be shot. If the coil packs are in good condition they do not need to be replaced. There are a number of things that can cause a rough idle.

any car without maintenance will fail.

fuel filter, spark plugs, spark plug wires, pvc valve all need to be replaced. (i highly reccomend it)