wifehhr

Yesterday my wife said that the t/c light came on while driving. When key was turned off and back on, light turned off. Now check engine light is on. I ran codes with p0301 present. No 1 cylinder miss. I did a compression check with no. 1 at 100 psi. Other three cylinders were only 130 to 140. This car has 96,000 miles and this is the second time for no. 1 miss-fire. at 30,000 miles dealer performed a valve job because of low compression on no. 1. Has any one else had two valve jobs at less than 100,000 miles. Engine is 2.4 with auto, 2006.

Lucky

I'm having a hard time undstanding that your can needed a vavle job at 30,000 miles. I would say thats rare unless there was some abuse or defective parts. then to see compression on number one lower than the rest again makes me wonder if your dealer is not being truthful with you. Maybe the dealer never realy did a valve job. put some oil in number one cyl. and check again. maybe the cyl washed with fuel from a leaky injector.

frey55

Also, make sure you are using a good quality fuel,(sunoco 93). I was dealing with a misfire on cyl. 4 for quite some time. Switching to Sunoco has cured the problem.

sleeper

Was the Comp test done with motor at operating temp ?

& Was the Throttle fully opened during cranking ?

wifehhr

I did squirt oil in the low cylinder, same 100 lbs compression. Sunoco 93! I haven't seen that since I drag raced ar Rockford Ill. (1980) I live in LIBERAL California where we're lucky we can still drive fossel fuel vehicles. I really do not think fuel will help. Remember It has 100 lbs of cranking compression. That is misfire territory. I quess that no one has had the same problem. Oh yea, it is driven mostly by my wife to her work which is 45 miles one way on a two lane freeway. Can't get driven better than that. I am the only other driver (our daughter will not drive a "clown car")

ssdivin

I have a 2008 ss w/ 65000 miles bad valve on cyl.3

Hib Halverson

I'm gonna bet that your code 0301 is not related to engine-mechanical issues...not with 100 lbs compression.

I'd start looking at the spark plug, the coil on plug or wires and connections relating to the ign. system.

chippersr6

I had the same miss-fire code on cyl. 3 at around 40k miles. All the same symptoms as you claimed in first thread. Dealer couldn't find the cause so I drove it like that for 6 months before I took it back to different dealer in IL. They had car for 4 weeks and couldn't find source and ended up just changing the head out completely under warranty. Haven't had problems with miss-firing since.

ChevyMgr

The problem is a steel valve seat coming loose from the aluminum head which makes a cylinder head replacement necessary.

wifehhr

Valve seat makes sense. I guess i'll have to replace the head. Today my wife also said that t/c is on, seems to happen the same time as check engine. What would this be.