Need help deciphering a cylinder leakdown test
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Need help deciphering a cylinder leakdown test
I need some input here from the more mechanically experienced. I did a compression test on the S2K. Results averaged 220, 180, 222, 228 with cylinder #2 being the oddball/PITA. Next I did a cylinder leakdown test. Here is what I found, but I'm not sure what it means:
Cylinder #1 - 7% leakage. Heard air coming from cylinder 2 and slightly from the removed dipstick hole.
Cylinder #2 - 52% leakage. Heard lots of air coming from cylinder 4, slightly from 3. Not much from dipstick.
Cylinder #3 - 7% leakage. Heard air coming from 1 and 2, slightly from dipstick.
Cylinder #4 - 4%. Heard air slightly coming from #3.
I retested #2 with the throttle butterfly held wide open, same results and I could hear air in the throttle neck.
No air bubbles in the radiator and no air coming from the exhaust. Never thrown an engine light, doesn't burn oil. I would have never guessed there was any issue. I adjusted the valves a few months ago. #2 was the tightest, with the exhaust valve being .23mm while the spec range is .25mm-.29mm. AP2's commonly have burnt valves from being too tight. Can anyone help with diagnosis?
Cylinder #1 - 7% leakage. Heard air coming from cylinder 2 and slightly from the removed dipstick hole.
Cylinder #2 - 52% leakage. Heard lots of air coming from cylinder 4, slightly from 3. Not much from dipstick.
Cylinder #3 - 7% leakage. Heard air coming from 1 and 2, slightly from dipstick.
Cylinder #4 - 4%. Heard air slightly coming from #3.
I retested #2 with the throttle butterfly held wide open, same results and I could hear air in the throttle neck.
No air bubbles in the radiator and no air coming from the exhaust. Never thrown an engine light, doesn't burn oil. I would have never guessed there was any issue. I adjusted the valves a few months ago. #2 was the tightest, with the exhaust valve being .23mm while the spec range is .25mm-.29mm. AP2's commonly have burnt valves from being too tight. Can anyone help with diagnosis?
Last edited by AutoXJeff; Apr 6, 2017 at 11:01 AM.
Joined: Aug 2016
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If you can hear it coming out of the throttle body and not the dipstick I would say your valves have burnt up. Could possibly be a bad valve adjustment though? I don't think that would effect it though even if the adjustment was too tight right now. If it was rings you would see fouling on the plug and have some oil burning and you'd hear the air through the dipstick so id rule that out.
Last edited by Mullallyman; Apr 6, 2017 at 06:56 AM.
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