i just took my car to have the compression tested and i got over 150 across the board. (JDM GSR motor)

the guy that looked at it said there's no way it could be rings, but i'm burning about a quart of oil a week.

we even took the oil cap off while it was running to see if any smoke came out, and there was nothing.

the engine is running too strongly to be rings... so i think i can take that off the list of causes.

the only other thing i can think of, is valve guide seals. this is a '95 GSR motor with roughly 40K miles, so i'm thinking that maybe because it's been sitting for so long, that the seals went bad?

the guy also said something about the oil lines being in backwards or going the wrong way.... think this could be it?

it only smokes when i start it up sometimes and rev it a little, or almost every time when i'm in the 5,600 - 8,000 RPM range.

any insight would be greatly appreciated.
thanks.

 

150psi for a JDM GSR is pretty low!

 

what should i be getting?

i thought that anywhere around 145 was good?

 

So your car defnitely smokes, but how can you be sure to attribute all of your oil loss to oil burning in the cylinder? Have you checked for a leak? Oil pan gasket can cause some serious leakage.

I would not cross off piston rings. Do another compression test (verify results), and then perform a leakdown test. Don't worry about the c-test #'s, just the difference between them (they are numerous variables in that test). I would say it is still the rings, with possible accopanyment from the valve seals/guides.

Edit: put a capfull of oil in each cylinder and see if the compression raises.

 

Check your cam seal (On the distributor side) for leaks too.

 

the cam seal does leak a little, but not nearly enough for all this oil to be disappearing.

thanks GSpeedR

i'm gonna try to get another compression test tomarrow at a different shop and try to put the cap full of oil in each cylinder like you said.

i'm pretty sure i'm not leaking oil... when i change my oil i try to look for any leaks while i'm under the car and i haven't noticed any.
the car doesn't leave any traces of oil on the ground after it sits all night.

god i hope it ain't rings...
i haven't even had the engine for 6 months yet.
that's like thowing $3500 down the drain.

 

150psi is a tad on the low side. Is it even across all 4? 1/quart a week is a ot and is probally not the rings. I'd go with valve seals. Do you a nice puff of blue smoke on a cold start coming from the exhaust?

Danny

 

i don't have the numbers with me, but they were all above 150.

when i start the car up sometimes, i'll get the blue smoke and then if i rev it up to about 4k a few times, it will blow out a lot of blue smoke, then it will go away.

when i take it up to 8k on the the highway, it blows out enough blue smoke that i can see a "blue haze" in my rear view mirror and i can smell oil burning as well.

this doesn't happen all the time, though... sometimes i'll rev to 8k while driving and not see any smoke or smell any oil burning.
or if it is smoking, it's not enough for me to see.

the car runs rich... i know that for a fact. but i doubt that has anything to do with it.

 

wow... i just did a search and it looks like the compression should be over 200... around 210.

150 is really low...

 

try the oil cap thing, if it raises compression a lot it's the rings, try this also, let the car idle for like 5 min, and tell a friend or somebody (that way you can stand in the back in the car and see this better) to rev the engine at wot for like a sec or two, you don't need to rev it to like 8K just the car to be a wot till like 5-6 K RPM, if you see a lil cloud of smoke (blue smoke) then it's valve guides seals.

BTW: if is rings you can still do a couple of tricks to restore them, sometimes it works great and sometimes it doesn't do nothing, but is soo cheap is worth the try.

 

If the motor was sitting around a long time, it is possible the rings are stuck in the grooves, not floating freely as they should. That would be caused by varnish or even a bit of rust. Possibly they can be freed up using some solvent or something like Marvel Mystery Oil. Put some in each cylinder, turn it over by hand with the plugs out, put the plugs back in and wait a few days. Take the plugs back out, turn it over to get the oil out, then put the plugs back in and try it. It's also possible after sitting a long time, the rings could have rusted to the cylinder walls and broke free when it was turned over. That could ruin the rings and leave a rough spot on the cylinders. Double check the cam timing, with the compression that low, maybe it is off?

 

It could also be the compression gage itself that is no good it seems odd that all four cylinders are low but still within 5-10% of each other.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by quik1 &raquo;</TD></TR><TR><TD CLASS="quote">It could also be the compression gage itself that is no good it seems odd that all four cylinders are low but still within 5-10% of each other.</TD></TR></TABLE>

Thats what I'm thinking, my ZC pulled just over 150 all the way across but I'm hangen with my budddys Spec-V and edging out 2000+ V6 stangs so it pulls great. It certainly shouldnt be assumed its just the tester, a leakdown test will provide much better insight.

 

thanks a lot guys...

the timing is all the way advanced. i have a hesitation or more like a stumble when i accelerate sometimes so my buddy tried to fix it by advancing the timing.

do you think this could cause the engine to use a little bit of oil?

hopefully i can get the compression checked again today.

thanks again.