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So today I did a leak down and a compression test, but the results I got left me stumped. While doing the leak down each cylinder had what seems like air coming from the front where the timing chain is. The compression test numbers just seemed off to me. The last time I did a compression the number didn't go as low as 220 and ranged from 225-240. No this time the numbers start at 190. My guess would be the head gasket since the leak down didn't have air coming from the exhaust or intake just need some advice on what I should do next before thinking the worst
leak down test were done in a completed ordered then retested
Are you sure the piston remained at Top Dead Centre during the leakdown test? I suggest you lower the air pressure when doing the leakdown to 50 psi. I found 100psi would push the piston down turning the crank and the cams opening the valves. TDC and 50psi worked for my tests. On compression, did you remove the fuel injector fuse and open the throttle to100%?
Are you sure the piston remained at Top Dead Centre during the leakdown test? I suggest you lower the air pressure when doing the leakdown to 50 psi. I found 100psi would push the piston down turning the crank and the cams opening the valves. TDC and 50psi worked for my tests. On compression, did you remove the fuel injector fuse and open the throttle to100%?
Piston did remain at TDC I found out that 100psi was to much and adjusted it to 90psi. On compression I did remove the fuse and had the throttle at 0% and 100%. Earlier this year I did a compression test after changing my intake retainers I had 220,225,230,240 all in that order so with the drop down to 190 I got worried. Car also has 163k on the motor.
You are nearing the limit on # 1&4 and over on #2. The leak down numbers don't really point to HG to me, plus there are other more apparent signs of HG failure that will show up over any leak down test such as contaminated oil. If you heard no air coming from the exhaust or intake side then that's not valves. You did mention hearing air escape from the front valve cover breather? That would be piston rings.
07-26-2017, 01:25 PM
Leak down and compression test
