GSX_Dan
20+ Year Contributor
- 138
- 4
- Jun 27, 2004
-
Chicago,
Illinois
Well I have a coolant overflow problem where it pushes the coolant out of the overflow once I get it into boost so I did a leakdown to check the headgasket. I also did a compression test and the numbers were 130-80-160-190 on 9:1cr pistons. The only piston that has proper compression is #4 
#1 under leakdown you can see the coolant neck bubbling pretty bad so that tells me the headgasket is pooched around that cylinder. Now the mystery is #2 because it doesn't bubble the coolant but the air comes out through the sparkplug wells(no plugs) for cylinders #1&3 and if I rotate #2 360 to the next TDC point the air comes out of #4cyl. How does this make sense? Do I need a valve job badly on #2 because air is leaking by and going into the intake then back in the other cylinders?
As far as #3 the leakdown didn't tell me much because I couldn't detect air coming out through the intake or exhaust and only the usual amount through the crankcase. It is possible that it was leaking by the exhaust valves since I can't listen for the air coming out until it hits the exhaust pipe and by then it's not very detectable unless it's a lot...Funny thing is a wet test brings up the compression a LOT for all cylinders but I already did the rings thinking that will fix my compression problems before the leaky HG problem appeared. Any help/input would be appreciated, thanks!
#1 under leakdown you can see the coolant neck bubbling pretty bad so that tells me the headgasket is pooched around that cylinder. Now the mystery is #2 because it doesn't bubble the coolant but the air comes out through the sparkplug wells(no plugs) for cylinders #1&3 and if I rotate #2 360 to the next TDC point the air comes out of #4cyl. How does this make sense? Do I need a valve job badly on #2 because air is leaking by and going into the intake then back in the other cylinders?
As far as #3 the leakdown didn't tell me much because I couldn't detect air coming out through the intake or exhaust and only the usual amount through the crankcase. It is possible that it was leaking by the exhaust valves since I can't listen for the air coming out until it hits the exhaust pipe and by then it's not very detectable unless it's a lot...Funny thing is a wet test brings up the compression a LOT for all cylinders but I already did the rings thinking that will fix my compression problems before the leaky HG problem appeared. Any help/input would be appreciated, thanks!
