hey
Question, i have a jdm gsr motor bone stock as far as i know, i hav been burning oil n smoking like hell for some months now, but my car still pulls strongly, finally got time to do a compression test yesterday, i got 220,225,225,220 across, now we found that 1. very high 4 a gsr, 2. my ring like they good, so thinkin the gauge faulty, we tested my friend's jdm itr motor right after, he did 210 across, then a nex stock gsr 190 across.
Why is my cars compression so high but i'm burning oil like ah ****, i'm smokin like crazy during acceleration...
motor has about 120k on it
Help people thanks

 

uhhh.. not to sound offensive... Did you check the oil? Too much oil in the motor will burn.

 

it was actually low on oil, had like half the max level

 

valve seals

 

X2...most likely, pop your valve cover off and check for any abnormalities on the rubber sections and do a leak down to see how everything is sealing just to double check things...

 

Oil can get past the compression rings even if they are working well.

If the oil 'scraper' rings are worn / stuck and thus permitting excessive oil to reach the compression rings (which are not primarily designed / intended to control oil, only to seal gas pressure, i.e. compression / combustion), then on the induction stroke the CRs will move to the top of the ring grooves (which is normal) which opens the bottom of the CR / ring land and some (hot / thinned) oil will find it's way into the space behind the CR (between the ring and piston, behind the ring in the ring groove). Oil may actually get 'pumped' into this space by the rapid downward motion of the piston, the scraping action of the CR and the inertia of the oil clinging to the cylinder wall.

On the compression and power strokes the CRs will move to the bottom of their ring grooves and the oil behind the lower CR can then find it's way into the space between the two CRs and from there into the space behind the upper CR and from there into the combustion chamber, and then be burnt. Some wear in the ring grooves could make this worse, even if the rings are still sealling gas pressures OK.

Excessive oil around the CRs would also help give good compression test readings, even if the CRs are not working all that well.

As suggested it could also be worn valve seals, but I think the guides and / or stems would also need to be significantly worn if you're burning a lot of oil (worn guides and / or stems means bigger gap through which oil can pass). There isn't much point in replacing only the valve seals on an engine with significantly worn guides / valve stems, the new seals tend not to last very long...

 

will do, thanks