shadowdawn

Well today we got around to doing the leakdown and there is bad news.
First off the compression #s were:

1: 195
2: 190
3: 190
4: 195

Leakdown was:

1: 2%
2: 9%
3: 6%
4: 2%

After checking possible leak areas from 2 and 3, Neither were letting air out from the intake side, Neither were going into the coolant system. However BOTH were definatly leaking into the exhaust, like blatantly after taking my WG off to listen.

My question is, given this info what do you all think is wrong, and how much **** am I.

I guess this is a lesson that compression tests dont show you much, especially since I might be looking at 2-4 bent/chipped valves I'm assuming.

Please help with experience and insight.

BoostedH23a1

probably a head gasket... my friend had one go out.. iwouldnt overheat or anything liek that.. power was fine.. but after we changed it it was all good. we couldnt even see where it was leakin.. make sure its not that u dont need a valve job or anything..

shadowdawn

Well my friend said a valve job couldn't have anything to do with it, since we checked and made 100% sure all the exhaust valves were "supposed" to be closed, we check that with the feeler gauges.

Head gasket doesn't make much sense, but I suppose thats hella better then valves I need a f-ing

shadowdawn

ttt

danl

If you hear gasses coming out the exhaust then you may have burnt or bent exhaust valves. What kind of leakdown numbers are out of spec for your car? The engine will still run, but not as powerfull. Do you have an EGT gauge? If so have where is it tapped and how hot did you run it? I'm betting some burnt valves IMO. Either that or bent valves if its a fresh install. Whats your vaccume at idle?

shadowdawn

more then 4% I would imagine are out of spec. I have an egt, tapped at the dp meeting the turbine. Highest I ever saw was mabye 900c. Not sure what you mean about vacum at idle, if you mean pressure its right around 750 which is stock and my idle is fine, nothing driving wise is different. And these 900c temps were seen long before my dyno was taken, so I couldn't say how long these leakdown numbers have been in place.

obd1

shadowdawn

Does anyone really know the definitive order of leakdown test results?
IE:
2% = A+
?% = definate rebuild.


[Modified by shadowdawn, 12:57 AM 3/19/2003]

shadowdawn

::

Stewie

Not that I know any better but, is it even possible for a bent valve to only let out less then 10%?

shadowdawn

Actually karim, the guys at rpm and viren both said we have acceptable leakdown #'s and in my case its most definatly the valve seats not the valves that are burnt/bent. Cause if they were bent or burnt I would be letting out more then just 9%. So by leakdown test standars our motors are in still descent shape.

No driving each other home from the track today :D

Drew Peacock

Well the compression test numbers are very good! I am not sure on the leak down numbers but they don't look that bad.. Are they definitely gone past normal wear and teartype of numbers?? Hows the car run?

shadowdawn

I'm not positive, both Viren and guys at rpmnyc (the shop that did my turbo install) said don't worry about it. The car drives fine, and the vacum at idle is -750kg or whatever which I know is what it should be. There is absolutly no difference in driving the car whatsoever.

Even still air should not seep past the valves when they are closed, thats just not healthy

FredoSP

my thoughts too, those # looks fine

shadowdawn

Well yea compression #'s look good, but obviously the leakdown shows the wear on my 2 and 3 cylindars, and its not that happy wear either, its fairly serious.

My point is SEE how I have awesome compression #'s but air blowing past 2 and 3 exhaust valves when they are closed....

FredoSP

How much did the leak down cost .. I have good comp #'s too .. grrr