Topic: Compression Test Results

[DanMarino]

Hi Guys,

My 1994 Wrangler with the 4 angry squirrels was having some blow-by last year.  I cleaned the PVC system and it helped a lot.  But it is still leaking a little oil and a mechanic indicated that the engine was worn out if it had blow-by like that.
So this evening I finally got around to doing a compression test.  The thing runs fine.  Here's the results.



Cylinder #1  140 psi dry, 150 psi wet,
Cylinder #2  140 psi dry, 160 psi wet,
Cylinder #3  150 psi dry, 170 psi wet,
Cylinder #4  140 psi dry, 170 psi wet,

I'm wondering if I didn't get enough oil into the cylinder when I did the wet test on cylinder #1.

Any ideas what to do next?  I don't have a leak down tester and don't really know how to use one.

Thanks,

13

[sharpxmen]

was that hot or cold?
did you do it with all spark plugs pulled out, the starter bypassed (not with the key so it won't spray gas in the cylinders) and with the throttle fully open?

[95 Lowbuck]

Those readings are not perfect, but not bad either.
I wouldn't tear into that motor unless it starts knocking or severe power loss.
Is it leaking around the cap, dipstick tube, or into the air cleaner?
A little around the cap I think is normal, check the gasket.

[dwtaylorpdx]

Ive done lots of trackside support racing, compression test is like when the dr puts a tongue depressor in your mouth, leakdown is the MRI.

[DanMarino]

It was a cold test.  I had the pedal down and cranked with the ignition key.