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1989 Ford Probe LX

11-21-2009, 06:16 PM
Took the probe to the mechanics and they say i have bad piston rings. So now i want to run a Compression test to check for myself to make sure they just didnt want to deal with the problem. So my question is how do you run the test and what the results would mean. I think i have a bad gasket because white smoke comes out of the exhaust pipe when you first start it for like 5 min. then stops.
thank you,

11-21-2009, 11:14 PM
Welcome to AF!

It is a normal thing for the exhaust to emit white smoke (steam) for the first few minutes of operation. If you had a bad head gasket it would do it all the time...even worse after it warmed up. To run a compression check pull all the plugs out of the head. Place the nozzle of the compression checker into the spark plug hole. Turn it over at starter speed. The highest reading you get is the compression. Bad compression can be caused not only by bad compression rings, but by bad valves, also. To determine whether the poor compression is caused by rings or valves is to add a couple squirts of oil into the spark plug hole and run the compression test again. If the compression comes up it is bad rings. If it doesn't come back up it is bad valves.

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