Ok, for those who might not recall, I'm in the process of peiceing together a turbo setup for my '99 Integra GS-R. I'm pretty close to "done" in terms of getting all the odds and ends together, but I decided to go ahead and give the car a compression check to give myself a reference for future post-turbo testing. Well after the test, I'm extremley concerned.. here's why.

I went ahead and did everything as I've done 100 times before, and here were the results:

160-200-120-200

I checked and rechecked, but kept comming up with the same numbers. Now I'm sure it's very easy to say "well duh Dave, your ringslands are toast", but here's why I don't get it. This motor (to my knowledge as I am not the first owner) has never been boosted, does not consume oil any more than a normal VTEC engine, does not smoke an ounce and lastly makes excellent power (161.5whp with a CAI alone).

So try and try as I may, I just can't fathom why I keep comming up with such lower numbers in #2 and #4 while #1 and #3 are perfect. The car runs teriffic in every single aspect including idle, stop and go and of course WOT.

So.... any idea's? Anybody ever seen something like this before? Any help would be greatly apprieciated!!

 

Did you try adding a lil oil in cyl 2 and 4 and see how much it bumps u up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civtek &raquo;</TD></TR><TR><TD CLASS="quote">Did you try adding a lil oil in cyl 2 and 4 and see how much it bumps u up?</TD></TR></TABLE>

Nope.. it was getting dark out and I was still overcomming shock..

 

i wouldn't boost that engine. Low compression is a bad thing. Boost makes problems like theese much worse. Drop some oil in there and see if the compression bumps up.

 

I usually don't rely on just a compression test..
Try doing a leak-down test. Its pretty simple.. just finding true TDC is the hardest part. 100psi is put through the spark plug hole when piston is at exact TDC
Any psi that is lost is the leak%, and you'll be able to hear where the leak is coming from..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Quick 200k Mile Motor &raquo;</TD></TR><TR><TD CLASS="quote">I usually don't rely on just a compression test..
Try doing a leak-down test. Its pretty simple.. just finding true TDC is the hardest part. 100psi is put through the spark plug hole when piston is at exact TDC
Any psi that is lost is the leak%, and you'll be able to hear where the leak is coming from..
</TD></TR></TABLE>

gie it another compression test, and base your thoughts on the two tests. my buddy compression tested his motor 245 245 190 245, next day 245 240 240 240 ....go figure, Leak down test,

 

Is it possible that the valve lash is out of spec or they were not adjusted properly and the valves are not fully closing on those cylinders?

 

It could be, but you would've had to set them too tight for them to do that.
With a leak down test you could find that out and even know which ones need to be adjusted..
Leak down test

 

Alright guys, I'm gonna go ahead and give her a leak down test and hope for the best

 

I had a problem once with the same type of issue. And the problem ended up being some trash stuck in the valve seat, and it cause some low compression. Try driving it on the highway a bit and then bring it home ands do the check after it cools some...

 

did you warm up your car b4 you did the compression test?

i heard you want it to be warm to get oil in all the necessary spots to seal properly...