Is it valves or rings ? Options

[jsteele22]

My '76 2.0L is putting out a little smoke on hard acceleration. Is there a way to tell if the oil is leaking past valves vs. piston rings ? The old trick I always heard was to test compression, put a little oil in the spark plug hole, and retest. But that won't work on a horizontal cylinder.

My hunch is that it's the valves, but only because its easier for someone (PO, not me !!!) to screw them up by not doing regular valve adjustments. My records are a little patchy, but I think the engine was rebuilt less than 50k mi. ago. Any consensus on what tends to go sooner ?

Thx

[jsteele22]

Wow,

You folks have chops. I never knew why leakdown was better than simple compression. Also, I would never have guessed that the "oil trick" worked on horizontal cylinders (I was kind of dubious about the slant of a V-8...) And Jake, man, you shattered my hopes of an easy fix...

Anyway, I'm having probelms passing emissions (see new thread) and I'll have the leakdown test done as part of that adventure...

Thx,
Jeff