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Author Topic: Cylinder 3 misfire  (Read 1809 times)

Offline Swatch19

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Cylinder 3 misfire
« on: September 16, 2024, 05:47:22 pm »
Need a bit off advice with 2008 Mk5 Gti Bwa engine, it has a bad misfire on #3 cylinder, plug was bad fouled with oil, replaced plug and coilpack and still have an intermittent misfire. Compression test is good across all cylinders. But there is oil pools on top of 2 pistons. Any suggestions?

Offline malithab

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Re: Cylinder 3 misfire
« Reply #1 on: October 13, 2024, 05:52:52 am »
Hello, I have the same issue. Mine is at 263k now. It runs without any issues when accelerated. But not smooth and misfire when idle. Some time I have to press the Gas a bit to get the car started.

Offline TyGTI

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Re: Cylinder 3 misfire
« Reply #2 on: October 14, 2024, 12:09:54 pm »
Oil on top of the pistons could be leaking valve stem oil seals.

When the engine is shut-off the oil in the head can leak down the valve stems and would sit on the pistons of the cylinders where the valves are open

That would produce some smoke on start up but burn off quickly. I doubt it was cause your intermittent miss fire though.