Compression Test Results/Question
11-22-2005, 01:33 PM
#1
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Compression Test Results/Question
Cyl 2,3,4,5 = 180ish
Cyl 6 = 170ish
Cyl 1...
This is strange, the first time you attach the gauge, turn the engine over, the highest reading you get is about 165ish. If you immediately release the pressure in the meter, and crank the engine again, you get like just about 180.
I duplicated this a couple times, and I don't think it'* how long my wife was turning the car over. The other cylinders went to 180 without fuss.
Cyl 6 = 170ish
Cyl 1...
This is strange, the first time you attach the gauge, turn the engine over, the highest reading you get is about 165ish. If you immediately release the pressure in the meter, and crank the engine again, you get like just about 180.
I duplicated this a couple times, and I don't think it'* how long my wife was turning the car over. The other cylinders went to 180 without fuss.
11-22-2005, 01:39 PM
#2
DINOSAURUS BOOSTUS
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how are you performing the test? I was leaving plugs etc in and that is the wrong way.
Paging Don...can you please remind us how to do this test properly....Don to the thread....Paging Don...
Paging Don...can you please remind us how to do this test properly....Don to the thread....Paging Don...
11-22-2005, 01:41 PM
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thanks Billboost for your help
I followed the procedure in the GM 97 Service Manual...
Took all the plugs out, in other words. I disabled the fuel and ignition systems... the only thing I didn't do, was yank out the PCM-- to scared of breaking it!
Is that OK?
I followed the procedure in the GM 97 Service Manual...
Took all the plugs out, in other words. I disabled the fuel and ignition systems... the only thing I didn't do, was yank out the PCM-- to scared of breaking it!
Is that OK?
11-22-2005, 01:44 PM
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Dry only
it was my understanding a wet test was only necessary if a cylinder was below 90psi, or not within 10% of the others.
I thought that 165ish for Cylinder 1 initially was not quite out of the 10% range...
it was my understanding a wet test was only necessary if a cylinder was below 90psi, or not within 10% of the others.
I thought that 165ish for Cylinder 1 initially was not quite out of the 10% range...
11-22-2005, 01:48 PM
#6
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That compression is pretty good... Nothing to worry about there...
Usually it takes a few strokes to get a good reading
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Usually it takes a few strokes to get a good reading
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11-22-2005, 02:17 PM
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In general, the way i was taught and way ive done it is, Unhook plug from ICM, remove all plugs, hook a battery charger up to the batter to keep constant steady power. let it crank over 6 times, since its a V6, on that last crank record the reading.
My shop teacher last year, a journeyman since 1970, showed us, I trust his knowledge hehe.
My shop teacher last year, a journeyman since 1970, showed us, I trust his knowledge hehe.
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