For the last month of so, my car (2006 2.4 auto) has had a random misfire. Always cylinder 4. It does it very randomly but you can definately feel it. The plug has always looked fine. I have replaced the twice just to check. I even swapped coils around and still is cylinder 4. Any ideas what else to check. Like I said, it only does it randomly and mostly at idle. Only code is P0304.

Thanks for any help

 

injector. run cleaner or seafoam through the gas tank. If that doesn't work go to the dealer.

 

outta warranty....talk to a guy today that works for chevy that told me to check compression. That the valves on the 2.4 tend to go bad. I dont understand how a bad valve could make it misfire randomly. I figure it would happen all the time.

Any opinions?

 

if there is no compression that cylinder will not fire causing it to miss. I really dont understand why GM is still staying with the stupid 2.4's there crap and they know it!!!!

 

I had the o-rings on the injector go bad on the #2 cylinder on my old cavalier and it was causing the misfire. I replaced coils, housing and plugs(needed em anyway) before i replaced the o-rings and it solved the problem. Might be worth it to just take a look.

 

bump.....

Still having same problem... pulled plugs 3 and 4 out....look burnt. Had a brown ring around the base of the Porcelain. I didnt pull out 1 or 2....in a couple weeks, I am going to change my valve cover gasket...thinking about putting on a new intake gasket and clean the throttle body and add a new gasket there too. Some new fuel injector o-rings too....

Anyone tell me a way to check the injectors off the vehicle?