Looking for opinions on compression numbers

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Crater05

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Nov 14, 2021
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Hello, I am just looking for some advice. So I noticed my '93 2.5l was idling a little funny, so I did a compression test on all 4 cylinders. All ranged between 60-75. I have read that at least 100-120 is optimal. If this is a problem what could it be?
 
Yes, thats low by a good stretch. You should by in the 120/150 range and each cyl within 10 to 15% of each other. Are you sure you had a good seal on the tester and held the throttle open all the way to allow for air to enter the cyls.
 
Gilaguy23 said:
Yes, thats low by a good stretch. You should by in the 120/150 range and each cyl within 10 to 15% of each other. Are you sure you had a good seal on the tester and held the throttle open all the way to allow for air to enter the cyls.
Click to expand...
Okay, I'll try one more time holding it full throttle to make sure before I try anything else.
 
If after your retest you do have that low of compression next step would be to do a leak down test to determine what is causing the problem. See here if you want to diy:

 
Warm and wet......If she's warm and still weak, Spray some WD-40 or PO into the cylinders and check again....No improvement?
If it's not smoking, That eliminates the rings and you probably have valve/head issues............
 
Chiltons say 135-155 psi
Put just a small amount of oil in the cylinder, through the spark plug hole and repeat test to see if it’s rings or valves. If compression does not improve with lil, then most likely valves.
My long block is at machine shop now going 30over.
Machine shop speaks highly of this little engine. ……
 
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