P0304 Misfire.... Low Compression Reading????

AsianAlero · 04-21-2008, 05:41 PM

So i had a misfire condition only at idle that i swore up and down was due to a bad or clogged injector. today i ran a compression test and it was 120psi on the bad cylinder while all the others were at 160psi. any input would be greatly appreciated. i read on an old post that someone had a rocker arm bolt which was not torqued down properly causing their miss at idle. any other ideas before i go chasing ghost?

cylinder 4 misfire only at idle. low compression at 120 psi. did a wet test and showed no change indicating rings are good.

thanks

TheEdgeofSanity · 04-21-2008, 06:09 PM

well, depending on engine, it may be time for a valve job....engine type? mileage?

AsianAlero · 04-21-2008, 07:37 PM

30k on 3400 jasper re-man

TheEdgeofSanity · 04-21-2008, 09:54 PM

well....i'd say valves...if it wasn't redone properly or aren't seated well then that would be a reason for compression loss. any warranty on the engine? you may want to take it to a professional to check it out before more damage is done.

AsianAlero · 04-21-2008, 09:56 PM

yeah i just dont have room for any down time with the car. i'm in tech school myself just theres no time between that and work.

TheEdgeofSanity · 04-21-2008, 10:02 PM

uhm....well, i'd say that you eventually need to get it looked at but as long as your willing to take the risk of screwing the whole engine then it'll be ok for awhile. In the mean time to try improving the running condition, maybe try some new spark plugs and a bottle of fuel injector cleaner?