Vetal

iTrader: (3)

In short, I did warm compression test on my 383ci and now, motor off the car, I did my first ever leak down test, and the results were terrible.
On cold engine, all 4 driver-side cylinders (did have time only for driver side) show between 55% and up to 70% leakage. I only hear sound coming from PCV (perhaps there was some from the valves but very minimal if any).
Test done with harbour freight leak down tester (only without label):


What am I doing wrong? Compression test (warm) showed around 145-150 psi on all cylinders so I'm confused

01_SuperSlow

iTrader: (7)

Engine has to be warm, and piston at top dead center.

http://www.carcraft.com/techarticles...r/viewall.html

Vetal

iTrader: (3)

Yes I read that, and I "rocked the piston around TDC to ensure the rings are seated".
BUT engine is cold and I can't think of the way to heat it until I put it back in the car

schnellttz06

I can tell you that the Harbor Freight leak down tester has horrible gauges. They are very inaccurate, replace the gauges with good ones from Northern Tool and then redo it. Do some research on it and you will see. Aside from that, if you have your air pressure on the compressor up too high it will leak out the crankcase.

Vetal

iTrader: (3)

Compressor pushed about 90-100psi, left gauge showed about 12-15psi during test (I guess that's what was pushed inside the cylinder?)
I guess best way to check what's wrong is to just pull the pistons...
Or maybe I could try this tester on another engine

SlowBurn

iTrader: (7)

I'm not sure I'd trust anything I read from a Harbor Freight diagnostic tool. Is there one you can use from a local parts store?

Vetal

iTrader: (3)

No... I ordered this one from USA too...