Bad compression but car runs fine. Opinions please!

[LOVE_dsm]

I recently did a compression test and ran 90 90 90 90. It drives fine despite the bad numbers, did the oil in each cylinder and did the compression test again 130 across the board. So that means they're bad rings right?

Is 90 very bad? Despite the fact that it runs fine? Smokes a little white, very little.



UPDATE---------------------------------------------------------



Did a compression test with a cap of oil in ever cylinder, compression went up to 130 across...... i hope its the headgasket!!!! LOl

 

[EGuenther]

Standard compression is 164psi at operating temp, the service limit is 121psi. Did you do your test cold or at oper. temp? Also remember to do the test at WOT.

 

[LOVE_dsm]

Standard compression is 164psi at operating temp, the service limit is 121psi. Did you do your test cold or at oper. temp?

operating, drove it then did the test .


time to rebuild the bottom end huh?

 

[EGuenther]

I would say next step is a leakdown test, just to be 100% sure its the rings. But if it drives fine and your not looking to crank up the power i would leave it until theres a problem like burining oil or something.

 

[LOVE_dsm]

I would say next step is a leakdown test, just to be 100% sure its the rings. But if it drives fine and your not looking to crank up the power i would leave it until theres a problem like burining oil or something.

barely smokes a little bit of white............ motor was rebuilt 3 years ago and only driven 50k!

yeah i was going to just wait til it goes KABOOOOOOM! car gets a i little hot as well.......

 

[EGuenther]

is it burning any coolant? It might be just be a head gasket even though its rare to have even low compression on all 4 with a bad head gasket. If its just bad rings theres no way coolant would get used. Small amounts of oil burning can burn white though......maybe its rings and a head gasket!

 

[LOVE_dsm]

yeh i think it's losing a bit of coolant, im checking it, yesterday it was full. Today it was not visible by just peaking in the radiator.


hmmmmmmmmm. oil levels the same......

 

[1990gsx1781]

yeh i think it's losing a bit of coolant, im checking it, yesterday it was full. Today it was not visible by just peaking in the radiator.


hmmmmmmmmm. oil levels the same......

im having the same problem. just dif. compression numbers im swapping my HG soon

 

[LOVE_dsm]

im having the same problem. just dif. compression numbers im swapping my HG soon

what numbers did you pull and what are your symptoms?

 

[1990gsx1781]

what numbers did you pull and what are your symptoms?

with full throttle i got from left to right 140,120,110,122. symptoms are i loss coolant i fill it and go for about a week or w.e depends how much i drive it and then i notice it start to heat up and i look and the res. is dry . also when i accl. then let off i notice my car like bogs out stops and bogs out like its misfiring.


oil level stays fine and i dnt really notice any water in it. spark plugs look white on the tip like water was in the Combustion chamber

 

[LOVE_dsm]

with full throttle i got from left to right 140,120,110,122. symptoms are i loss coolant i fill it and go for about a week or w.e depends how much i drive it and then i notice it start to heat up and i look and the res. is dry . also when i accl. then let off i notice my car like bogs out stops and bogs out like its misfiring.


oil level stays fine and i dnt really notice any water in it. spark plugs look white on the tip like water was in the Combustion chamber

copy that sir!!!! same thing is happening to me

 

[1990gsx1781]

copy that sir!!!! same thing is happening to me

haha yay finally i found some1 with the same problem so everyone is telling me its the HG so for the hell of it im gonna take the chance and just redo the headgasket it seems like it is. i just dont want it to totally blow on me.. mine still runs really good and its fast so i cant wait to feel it with good compression haha

 

[SpawnedX]

Out of curiosity, are you able to try a different compression tester? You can usually rent one at AutoZone, I think you need to put 75.00 down or something, but you get it all back when you return the tool in working order.

I doubt your tester is bad, but it's cheaper then ripping things apart.

Other then that sounds like a head gasket bro.

Best of luck.

 

[1sick91tsi]

i found this thread kind of funny because i actually had the same exact compression numbers at one point. my car ran great but was a little low on times for the parts i had on it. i managed a 12.7 at 113 with a scm6152e at 26 psi and i new something was off. checked compression and i only had 90psi across the board. personally i would say just run it untill it blows or re-build it.

 

[awesomex]

haha yay finally i found some1 with the same problem so everyone is telling me its the HG so for the hell of it im gonna take the chance and just redo the headgasket it seems like it is. i just dont want it to totally blow on me.. mine still runs really good and its fast so i cant wait to feel it with good compression haha

my gvr4 runs good now, with the compression 90 across the board, but i think ima go ahead and change out the headgasket as well!



keep me updated on your status

 

[LOVE_dsm]

i found this thread kind of funny because i actually had the same exact compression numbers at one point. my car ran great but was a little low on times for the parts i had on it. i managed a 12.7 at 113 with a scm6152e at 26 psi and i new something was off. checked compression and i only had 90psi across the board. personally i would say just run it untill it blows or re-build it.

yeah, ride til' i die.......


thanks for your input everyone keep it comin'!

 

[SpawnedX]

I have actually been thinking on this all day, I think you need to check your timing, maybe your valves aren't fully opening, but due to the fact that you tell us that oil is bringing the compression up, I am thinking oil as acting as a sealant around your rings which are not making proper contact to the cylinder wall.

I think you are going to need new rings.

 

[1990gsx1781]

hey if you do the head gasket please let me know if it worked =)