Compression test results, How bad is it?
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Compression test results, How bad is it?
Ok, trying to diagnose power probems, did a dry compression test and this is what I got
138
135
135
135
135
145
140
127
This was done with a pretty cheap gauge, but still its pretty consistent.
138
135
135
135
135
145
140
127
This was done with a pretty cheap gauge, but still its pretty consistent.
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93k miles, is a wet test really necessary since they are so close anyway, I thought it was just used to try to diagnose if one was off.
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Hmmmm, now those numbers look a bit low to me, as I'd be guessing that 8 cylinders in the mid 150's---> low160's would be a bit better.
Did you do this test with the engine warm?........
Lead Driver
Joined: Aug 2006
Posts: 5,670
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From: Sand Lake, MI
Was the motor up to running temp for testing? did you remove all the spark plugs and hold the throttle full open during cranking, and using a strong battery?
Allowing each cylinder 3 compression strokes to build full pressure?
Did the pressure rise quickly in each one? Reaching the max number for the given cylinder in those 3 hits?
Your numbers you got might be a little low if you didn't do one or all of the above while testing, say you only took out one plug at a time or didn't hold the throttle open or both, but even at that your numbers are fine.
The wear is even, that being the important thing.
No need to wet test, your numbers do not suggest a problem where you'd want or need to go further with testing.
Allowing each cylinder 3 compression strokes to build full pressure?
Did the pressure rise quickly in each one? Reaching the max number for the given cylinder in those 3 hits?
Your numbers you got might be a little low if you didn't do one or all of the above while testing, say you only took out one plug at a time or didn't hold the throttle open or both, but even at that your numbers are fine.
The wear is even, that being the important thing.
No need to wet test, your numbers do not suggest a problem where you'd want or need to go further with testing.
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Thanks for the replies, I think this Im in the clear and can go on to the next thing. The engine was warm, but had cooled a little while I went about setting up for the test, Def below normal operating.
oh and..
It rose to 95 on the first jump, then 120 then the final number
also had a battery charger connected.
oh and..
It rose to 95 on the first jump, then 120 then the final number
also had a battery charger connected.
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Yep, all original no real rust, clean interior. I love the truck I just want to get it to where I have faith in driving it anywhere. The biggest problems I have had with it is because it has sat so much alot of seals dried out. So I have replaced many gaskets
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