leakdown test questions, i need answers FAST, please help

INFORMATION G2IC Archives
1

I’ve been having some oil consumption problems ever since my rebuild about 5000 km’s ago.

Anyway, the mechanic that did my engine is going to do a leakdown on it for me tonight.

So, I need to know what i should look for, what acceptable leak down percentages are, etc.

Any help would be greatly appreciated!

I’m going to his place after work, in about 5 hours.

:slight_smile:

THanks,
Adam

2

i don’t remember % but heres what we always did.
air from dipstick = bad rings
air from oil cap = valve seals
air from rad. = h gasket
air from intake = bad intake valve
air from exhaust = bad exh. valve
if more than one happened at a time then we pinpointed with percentages.

3

Average leakdown for a good motor is near 6-8%. Anything over 10% is bad, and anything under 6 is really good. Hope this helps.

4

archivethis

5

Originally posted by G2guru
Average leakdown for a good motor is near 6-8%. Anything over 10% is bad, and anything under 6 is really good. Hope this helps.

Thanks Dan, that does help.

I had him do the test last night, and according to him everything is fine.

All cylinders were at TDC and the car was warm when the test was done.

I couldn’t hear or feel any air coming out anywhere (ie intake manifold, exhaust, dipstick, etc.), and all of the cylinders were under 10% except one which I think was around 18. The mechanic told me everything is fine, and since I couldn’t hear or feel air coming from anywhere I sort of believed him.

I’m starting to think otherwise now, what should I do?

Thanks,
Adam

6

Adam,

18psi is a little high, but doesn’t mean your motor is dead. It’s something to be concerned with though. You need a mechanics stethescope to hear the air coming from the crankcase through the dipstick hole. Acura raises the red flag if any cylinder is above 12psi.