i just did a compression test this morning and was wondering
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i just did a compression test this morning and was wondering
cyl # 1 142 cyl # 2 140
cyl # 3 145 cyl # 4 132
cyl # 5 140 cyl # 6 145
Anybody else ever do a compression test? Does this sound OK, I am wondering why #4 is lower than the rest and is 140ish the right ballpark.
cyl # 3 145 cyl # 4 132
cyl # 5 140 cyl # 6 145
Anybody else ever do a compression test? Does this sound OK, I am wondering why #4 is lower than the rest and is 140ish the right ballpark.
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They seem fine, #4 is a bit low though hard to get to?
Try a shot of engine oil in the cylinder and try again, the oil will create a better seal, if the compression does not come up it could be a valve or head gasket?
Try a shot of engine oil in the cylinder and try again, the oil will create a better seal, if the compression does not come up it could be a valve or head gasket?
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Originally Posted by PontiacDad
They seem fine, #4 is a bit low though hard to get to?
Try a shot of engine oil in the cylinder and try again, the oil will create a better seal, if the compression does not come up it could be a valve or head gasket?
Try a shot of engine oil in the cylinder and try again, the oil will create a better seal, if the compression does not come up it could be a valve or head gasket?
not too shabby though. I put a junk yard head on my Shadow in an emergency, and the car didn't run to great... in the higher RPM'*, it would scream, but you could barely keep it running at idle. I did a compression check, and wouldn't you know it - 35 psi! yes, that'* right, I didn't forget the 1 there... it was amazing the little beasite even ran!
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Most importantly is that all cylinders are within 10% of each other. You can try the oil as mentioned above, and continue to monitor the situation, but in the meantime you have nothing to worry about.
Cheers,
Cheers,
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Aren't our cars (Series I anyhow) supposed to have around 175-180 when new? I had a compression test done on Ol Blue last summer and she showed 165-170 across the board. When I get my plugs exchanged for the correct plugs I will get the tester out and check Goldmember'* compression.
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So is it supposed to be around 180 ? Im at 140 does that mean my engine is worn out?
Anybody have actual compression readings from your own cars?
Anybody have actual compression readings from your own cars?
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Originally Posted by marksssei
So is it supposed to be around 180 ? Im at 140 does that mean my engine is worn out?
Anybody have actual compression readings from your own cars?
Anybody have actual compression readings from your own cars?
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The online GM Service Manual doesn't give a specific psi number as optimal, but it does say;
I would guess 180 psi to be quite high.
Cheers,
I would guess 180 psi to be quite high.
Cheers,