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is 40 psi difrence in comp ok
thunderace - 18/9/08 at 10:09 PM

is 40 psi difrence in comp ok

have just done a comp test on a golf 18 16v kr for a pal one is 190pis and the lowest comp is 160psi is this ok.

westf27 - 18/9/08 at 10:16 PM

assuming no leaks on test equipment then that is suggesting somethings happening.Put small quantity ofoil into the low bore pressure and repeat test on cylinder.if its better then probs rings/piston,if not probs burnt exhaust valve.

andylancaster3000 - 18/9/08 at 10:33 PM

We've had a similar problem a number of times now and that delta in pressures has been due to the head gasket. Looks like your head will have to come off i'm afraid to say.

Danozeman - 19/9/08 at 05:48 AM

Youv got a prob as said. Follow what westf27 says to eliminate the rings.

Mr Whippy - 19/9/08 at 06:37 AM

too much of a difference unfortunately, if the two center cylinders have the lowest pressure then it will be the gasket as the gap between them is the smallest and hottest area

02GF74 - 19/9/08 at 06:52 AM

is it just me but I make it 30 psi difference.

procomp - 19/9/08 at 07:13 AM

Hi for a test to give better indication of where the pressure is being lost try and find someone who can do a leak down test. This will give you the exact % being lost and exactly where it is being lost.

It will still be a head off job eventually but will give you a better idea of where to look if the problem is not so obvious.

Cheers Matt

Mr Whippy - 19/9/08 at 07:34 AM

quote:
Originally posted by 02GF74
is it just me but I make it 30 psi difference.


must be some sort of error factor...

britishtrident - 19/9/08 at 07:37 AM

My guess would be a valve but ideally do Leak down test --- if is actually posible to make a DIY leak down tester instructions are somewhere out on the web.