Thread: Take a look at these compression numbers

How do these compression figures look:

Engine was warm (not hot), all plugs removed.
(Background: I'm chasing a small headgasket leak on this high mileage motor, want to determine if it's worth redoing the heads on, or should I grab a lower mile unit to put in instead. Most of these look very good save for cyl 6)

Dry:
1 - 140
2 - 150
3 - 145
4 - 145
5 - 145
6 - 135

Wet (squirt of oil)
1 - 150
2 - 160
3 - 155
4 - 170
5 - 160
6 - 145

Originally Posted by BillBoost37

I always see them around 180, even high mileage. Which likely means you didn't block open the TB etc.

That aside.. they are all pretty close. That's good.

You would be correct. I was lazy and kept reaching in thru the window to crank it over. I'll spot check a few of the easy ones tonight with proping the TB open.


I'm also thinking of doing a leakdown to see if one of the cyls leaks into the water jacket. Machine shop said he's only ever seen warped heads and burnt exhaust valves. And even a warped head is pretty rare. But the PO's had neglected the deathcool and everything was pretty clogged. So overheating probably happened at some point.