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Compression Test Results: Thoughts Requested

Thread: Compression Test Results: Thoughts Requested

  1. beretta96's Avatar

    beretta96 said:

    Compression Test Results: Thoughts Requested

    I have a 2006 Focus ZX5 on which I recently changed the spark plugs. 3 of the 4 cylinders had oil on the threads and in the wells. I checked the oil and it was full. It doesn't smoke, sound bad or anything of the sort. It still seemingly runs great. I did a compression test with the car completely cold and got the following results:

    Cylinder 1: 240 -- 260 (wet) This is the one that didn't have oil on the threads when I changed the plugs.
    Cylinder 2: 230 -- 260 (wet)
    Cylinder 3: 240 -- 265 (wet)
    Cylinder 4: 235 -- 265 (wet)

    Based on my Googling, those results don't seem to indicate there is a problem with the pistons/rings nor does it seem to indicate a head gasket leak. Based on these results, along with there being a little bit of oily grime in the center cavity of the valve cover, I'm leaning towards it being a valve cover gasket leak.

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  2. Duchess's Avatar

    Duchess said:
    I would guess the same thing unless there's something else that could leak oil into the plug holes. Maybe someone spilled (a lot of) oil during an oil change? Most likely valve cover gasket, though. Certainly one of the best leaks you can have if that's it.