'82 6.2 very low compression on all cyls

[Steve_87K5]

Finally got around to cranking an old Goodwrench red-block C-code 6.2 a guy gave me. It sat for a long, long time in a junked suburban and the guy told me it was probably a good engine, since he had received it new under engine replacement warranty. Supposedly a low mileage engine.

I have it on a stand with a geared starter and an Optima battery. All glow
plugs removed, diesel test PSI gauge screwed into glow hole.

Primed the oil pump with elec drill. Good oil pressure. Squirted 30 weight in cyls thru glow hole, cranked it a bit to blow out some oil, and let it sit. Then, later, all cyls tested at about 125 PSI. Couldn't believe it, so I hooked up my gas compression gauge to it. Same results.

I have some MM oil in there now just soaking. Maybe the rings are seized?

Any ideas?

 

[kennyw]

I'd guess the rings have stuck from sitting more than anything. Do you have the tools to do a leak down test?

 

[Steve_87K5]

I have never done a leak down test but I have
heard of it. I had an article one time describing how to build a home made
leak down test rig.