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Cylinder #4 misfire

K

Kompton

New member
All I know is ive changed the plugs, wires....coils and Igniton module are fine..Took it to autozone had them run diagnostic's on it said cylinder 4 misfire and o2 senser heat was out.....could a simple o2 senser cause that much of a problem??? And I was reading the other thread and i'm gonna try switching the injector's and see if that fallows and is that something hard to do?? And it's not a problem at any certain rpm hot or cold you can tell a cylinder isn't running..any info help's...
 


is it always misfiring? does the SES flash? does it change cylinders? is it a blatant misfire, or can you only tell if youre scanning?

my car misfires at idle, changing cylinders. ive changed everything and it is still there so i gave up on it.
 
it's deff. blatant misfire and yes the SES is flashing most of the time sometimes just stay's solid....no it doesn't change cylinder's
 
switch the injector first to see if it changes cylinders.

otherwise if its not that and you changed everything else, then i would start looking into taking the car apart to see if anything is messed up.
 


^^^Compression test is a great idea. That way you can rule out a serious problem. You could change the O2 sensor as well since that was one of the codes.
 
yeah just taking me a bit of time to get around to...cold weather no shop=no fun working ona car in 15 degree weather lol thank's for the suggestion's
 
Ok got the compression test done today....showed cylinder 4 has 0 compression....guessing either a bent valve or stuck possibly...sparkplug looked perfectly fine like it was just outta of the box...no black on it at all so thinking the gas just flying right out the exhaust...any info would help...
thank's

Kurt
 
i bet you have a bent valve or your valve guides are messed up. the valve is no longer seating fully when closed. either way youre going to have to take the heads off to figure it out anyway.

get to it.
 
yeah...gotta get it to the shop don't have the tools here and the freezing weather never helps...either way thank's for the info.....will post back a.s.a.p. once I get to it
 


Kompton said:
All I know is ive changed the plugs, wires....coils and Igniton module are fine..Took it to autozone had them run diagnostic's on it said cylinder 4 misfire and o2 senser heat was out.....could a simple o2 senser cause that much of a problem??? And I was reading the other thread and i'm gonna try switching the injector's and see if that fallows and is that something hard to do?? And it's not a problem at any certain rpm hot or cold you can tell a cylinder isn't running..any info help's...
Click to expand...
my car had an egr problem and would only misfire on #4 cylinder. Replaced egr and cleared the codes and now no misfire and no more ses light!
 
ahh don't think it would be the egr if the compression test showed up with 0 no compression whatsoever...thank's for the suggestion though....only problem is now is workin through the foot of snow we just got over night lol you know
 
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