I have IX with 720 miles, I did a compression test and had 118,118,116,116. As a test I added oil to the 4th cyl and got a 150. Is this normal? How long does it take for the rings to seal?

 

Did you do it hot or cold?

 

unless you did the test wrong, thats awful low.. range for an 03 is 150-160.. the rings should be seated.. how did you break the car in..

 

dang, sounds like ring damage. what did you do? ring should seat in less than 20 miles.

 

the car was cold, would it make that big of a difference? 50PSI?

 

Dunno if it'd make a difference, but go drive it and get it warmed up, then do it just to make sure that isnt the problem.

 

test; engine operating temp, all 4 plugs out, no more than 4-5 turns till at full psi.. throttle open or closed no diff... you should prob be around 180-200 range.. if your still low, put a little oil in the plug hole, (piston), crank again.. if comp. raises, you have bad rings, or unsealed rings.. again how did you break he car in.. if you typed this before, you might have saved me all this damn typing..

 

sorry, but if you dont know, why post and take the chance of giving the wrong info... ..

 

Why no more than 4-5? My psi still climbs till about 6-7 turns.

 

Maybe you got a faulty gauge that reads low, you are getting constant reading across all 4 cylinder, its very rare that all of them went bad. I would borrow or buy another gauge to test it out. I think you are ok. If you read 170 170 115 170...then you have some problems.

 

Do the test with the car fully warm. The numbers will be a lot higher. Pretty sure you'll be happy with the results

shiv

 

This pics may help. These are straight from the 2003 service manual.

 

Considering all of them are low, I would say the test was done incorrectly.

 

Rings will seat within the first 10-15 minutes when the car is first started so they are definitely seated. I say you just did the test wrong. Ive always done all of my tests with the car warm and always held throttle wide open while cranking car. Im sure your car is fine.

 

I would try a diff comp tester. I've seen this many times before...

Mark
Turbotrix