compression test results b17
- Thread starter 408DB2
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408DB2
New Member
I was just curious to see what's the condition of my engine. The car runs fine with no issues. Is there a particular reason why cylinders 2 and 3 were slight lower than 1 and 4 cylinder?Thats not too bad considering the miles.
Can I ask why did you do the compression test now?
Muckman
Not a M0derator
Sometimes if 2 cylinders are equally low that can mean the tbelt is off. But if you havent done anything cam related then its not that. You can try adding 1 cap full of oil and see if the numbers come up in those cylinders. That will tell you if the rings are the source of the leak.
408DB2
New Member
Ok cool ill definitely do that. Anything else that i should look for? Lets say the numbers stay the same or go lower...?Sometimes if 2 cylinders are equally low that can mean the tbelt is off. But if you havent done anything cam related then its not that. You can try adding 1 cap full of oil and see if the numbers come up in those cylinders. That will tell you if the rings are the source of the leak.
Muckman
Not a M0derator
If the numbers go up alot (around where the others are) with a "wet" compression test that means the oil did its job and pluged the leaking rings.
If the numbers only go up a few points then the rings arent the issue, its likely leaking from the valves.
Honestly 150~165psi isnt that bad for an old motor.
If the numbers only go up a few points then the rings arent the issue, its likely leaking from the valves.
Honestly 150~165psi isnt that bad for an old motor.
Nick_C78
New Member
Yeah, those numbers aren't that bad. I agree with Muckman on this. I suppose it could also be the head gasket, right between both those cylinders, but I doubt it, since the numbers are still decent. Sounds more like normal wear, but still damn good for the miles. Not something to really worry about at this time.
djzachtyler
Looking for my next Teg..
I wouldn't say that having compression off by that margin is necessarily OK...
could indicate a few things... worn rings, leaking valves, or head gasket in your worst case. Perform a "wet" test using oil like Muckman mentioned in his reply and post back if you achjeved different results.
could indicate a few things... worn rings, leaking valves, or head gasket in your worst case. Perform a "wet" test using oil like Muckman mentioned in his reply and post back if you achjeved different results.
Samurai_Blue
Yolo Whippin'
I always thought good compression meant each cylinder was +/- 10PSI from each other.
djzachtyler
Looking for my next Teg..
that sounds about right definitely don't want more that a 10% variance...
Samurai_Blue
Yolo Whippin'
IMO if the OP is concerned about compression etc, a leakdown test would be beneficial.
nick92
92 lowered da
yes ive heard 135 is minimum before also and that u dont want more that 10-15 diff between cylnders, but i recently did a compression test on my 93 with 255k on it and it only had and average between 115 -125, but still runs great barks tires to 3rd and has no problem getting to 133mph. but yes you dont want anything that low if possible. but hey if its runnin fine and idling fine leave it beI believe that its a minimum of 135psi in each cylinder but a compression test; you're mainly looking for variance between each cylinder. I think that maximum variance allowed is about 25psi.