Mechanics

OIL ON 1 PISTON

2003 Mazda Protege

Engine Mechanical problem
2003 Mazda Protege 4 cyl Front Wheel Drive Manual 61000 miles

My mazda protege emits smoke from the exhaust at startup for about 5 seconds. I can't tell if the smoke is white or blue but its not a lot. The car has no leaks, and I noticed one piston is covered with black gluey stuff which looks like oil. The other three pistons are okay.

I suspect its either the o-rings or valve seals, but leaning more towards the valve seals since it doesn't emigate smoke while driving, just at startup. I going to have a compression test, but was wondering how much would repairing the o-rings or valve seal cost?
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Githua92
April 4, 2009.



Hi githua92,

If the stuff you noticed is on the plug body and not at electrode, it should be the valve cover or plug seals that are bad. Oil leaking into plug hole would cause misfiring when the amount of oil accumulates and causes misfiring of the sparks. A valve cover gasket replacement should take care of it.

Test spark plug wire resistance to check if it is ok. Should have continuity but resistance less than 25k ohms.

The labor time for valve seal replacement is listed at 8.4hours which I doubt is the main cause.

KHLow2008
Apr 8, 2009.


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