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Cylinder 4 misfire

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Afternoon all

Had the P0304 code come up which is a misfire on cylinder 4. I've changed the coil pack but the cel has come back on.

What else can I check on the run/system further back from the coil? Spark plugs are only 3k old

Thanks in advance


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you can try a few things, as said, spark plugs/gap, ht leads, coil pack, etc etc but it all costs money and may not solve it. advantage of goign to a specialist is they can try a few things to see if it solves the problem.


The other issue with misfire codes is they might not actualy be misfire, might be a default code its used. My dads kept getting missfire on cylinder 3, turned out to be something rather more sinister

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I agree tidgy it can work out cheaper to pay for a fault find than buying random parts and if a cylinder looses compression it can also give a misfire code but the spark plugs might show oil fouling to indicate loss of compression

I'm lucky enough to have at least half a scoob in boxes in my shed [emoji4]

But the op could re gap the plugs to 0.7 ,switch ht lead from cylinder 1 to cylinder 4 reset the ecu and see if the fault code comes back on cylinder number 1 instead (if at all) .which would just cost time not money [emoji6]

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Evening all

Thanks for all the suggestions. Will try the lead swap tomorrow but I've got a feeling this blow will be the problem. It's pretty bad and sounds like a tractor at the moment. I've had the other side repaired as this was blowing as well as the threads had got so weak the bolts just would not tighten anymore. It was helicoiled and has been fine since so will get the same done to this side.


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