Hey guys,

So I have been having oil leaking out of my oil fill cap and oil dipstick more and more recently. figured it was lots of blow by and today I pulled the plugs and did a compression test.

1989 305 TPI 165,000 miles
Passenger Side Driver Side
#8 210psi 180psi #7
#6 180psi 185psi #5
#4 210psi 185psi #3
#2 210psi 180psi #1

the numbers aren't low but the variance is concerning. is this engine junk or am I just misdiagnosing the oil leaks?

 

Those #s look OK to me for yerbasic peanut-cammed high-mileage untouched motor. Looks like you could stand to adjust the rockers. That's prolly bring the high ones back down where they belong.

More likely, your blowby problem is exhaust getting into the crankcase either through exhaust valve guides, intake manifold gaskets, or both.

And of course, make sure your PCV system is all operating correctly.

 

The intake manifold gasket leak theory seems the most likely to me. I actually had some oil accumulating on the top of the intake manifold earlier this year. I'm gonna double check my pcv systems before I commit to pulling the intake manifold.

 

Had the same happening on a buddys 91 305 TPI a few weeks ago. Ended up in an engine swap. Five broken and crumbled piston rings found in the oilpan. That engine was the biggest mess I've ever seen. Maintenance = None.