Complete valve job fixed the miss on idle on the Cobalt. Kind of wierd misfire was only on idle. A reputable machine shop I have used for the last 20 years said he has been seeing wierd problems like this mainly on 3.7 in Jeeps. Thanks for everybody's input it was greatly appreciated.

2006 TOYOTA RAV4 LIMITED, A/C BLOWS WARM, COMPRESSOR CLUTCH ENGAGES BUT DOES NOT PUMP FREON. GAUGE LOW & HIGH SIDE DON'T CHANGE. REPLACED COMPRESSOR; WORKED FOR TWO DAYS, NOW SAME AS BEFORE.

curtis81 wrote:DID U CHECK THE IGNITION COIL ON THAT CYLINDER?

It has a coil pack & it checks Good

I assume the machine shop also checked valves and head warpage. Maybe do a running compresion test, that should seperate a mechanical issue from other issue. I'm guessing it wasn't running so well when it came in. The head was warped and milled. Can not do a running compression test due to coil pac...

I have a cylinder #3 misfire only at idle on a 2006 Chevy Cobalt with a 2.2 liter after replacing the head gasket because it was severly overheated. We have replaced the spark plugs, fuel injector, map sensor. Off idle it runs good and the misfire is gone. We have no vacuum leaks. The cylinder head ...