95 integra ls compression test results low

[chrissm14]

just did a compression test and heres my results:
cylinder 1-2-3-4
Results:135-125-140-145

i added oil to cylinder 1 and got it to go to 150psi, but the o ring is shot on the gauge so i didnt try the others with oil. any ideas what this could be? the car only has 126k original miles....

 

[chrissm14]

also my valves are making a loud chattering noise, i think its time to do a valve lash. if the valves are out of spec, could this cause my low compression?

 

[gugiey]

I would confirm your results with a leakdown test .

 

[DC4GoFast]

Change the o-ring on the tester first thats probably why your numbers are low

 

[chrissm14]

Change the o-ring on the tester first thats probably why your numbers are low

it was a brand new loaner tester from autozone, the first few test i did there didnt sound like any air leaking but once the o ring blew out the side i could here air 'squirting' out of the cylinder that the gauge was in.

 

[chrissm14]

Change the o-ring on the tester first thats probably why your numbers are low

you were right! ive always had nothing but problems with parts from autozone, if i never have to get another pos part from there ill be happy. the gauge i rented was brand new still in the package, and i got those shitty readings with it. today i was at my girlfriends dads house and he had a tester thats probably at least 20 years old, and i used that and got 185 psi across the board. i also fixed my stupid idle problem, there was just a vaccuum leak under the map sensor becuase i forgot to put an oring in there, and now it runs fine. also set the timing at 18 degrees btdc, filled her up with premium gas, and now she runs like a dream!!

 

[Spawne32]

did you have your foot with the gas pedal to the floor when you were running your test, and did you have the ECU and Backup fuse pulled?

 

[chrissm14]

did you have your foot with the gas pedal to the floor when you were running your test, and did you have the ECU and Backup fuse pulled?

yes i had it at WOT, and had the pgm-fi fuse removed. its not neccessary to remove the backup fuse.