74goldtarga

I read a few threads on here about compression tests (Refresh and Paulyy) and thought I would check my compression for a couple of reasons: my engine is newly rebuilt and should be good, my car was nearly overheating on track my first day out and blew white smoke out the tailpipe for a couple of minutes on startup on one occasion that day (but not since), I had some water in my catch can - not sure if condensation or from mixing but no water in drained oil from oilpan, and finally, I had an S2 catching me on a straightaway - granted it is a very high level build but that didn't seem right to me.

Anyway, results with engine warm and throttle wide-open were 123-135-133-138 from front to back. Based on other posts this would seem to be low, especially for a fresh engine leading me to believe that I may have damaged it. I am planning to do a leakdown test with a mechanic friend of mine (he's not that close of a friend so I hope we can find a time to do it). What should we be looking for with the leakdown test? If it fails the next step to remove the head and inspect the gasket and cylinder walls correct? Thanks in advance for input.

By the way, I never ran more than 14.5psi boost and my gauge measures peak boost so there were no spikes higher than about 15.5. I had no overheating issues for 2 track days, it was just the first time out that was a problem due to an exhaust leak in the crossover (02 sensor came out of the bung) now fixed.

Paulyy

water in your catch can? hmmm.

when i did my compression test while the engine is cold i opened the expansion tank and a lot of water come blowing out the filler hole.
So go to your car and remove the DME relay (so it doesn't start) and crank it a few times and open coolant cap and see if water comes out, if it does well your headgasket is finished. if it doesn't either there's something wrong with the motor or the headgasket still might be gone.
Just a simple test before you go to the mechanics
Goodluck!

74goldtarga

Thanks Paulyy, I can try that. When I say water in the catch can I mean not much at all after the car had sat quite awhile without draining the can, I understand that water vapor is one of the things that ends up in there along with aerosolized oil droplets so water should not necessarily be abnormal in small amounts but I'm not sure if this is true. Thanks again.

74goldtarga

Cranked the engine and no water out the filler hole with removal of the cap. Thanks for the tip.

Paulyy

having doubts its your headgasket. do a leakdown with your mechanic. he'll know whats going on

333pg333

Water in catchcan is nothing unusual, especially with tracked cars.

74goldtarga

Just realized, my car wasn't using or burning hardly any oil at the track, that makes it pretty unlikely that there is a problem with the rings / bores - correct?

Paulyy

your valved may not be seated properly? could be a suggestion and have a check.

74goldtarga

Have to say thank you to the Australian 951 community for chiming in.