I own a 82 gmc pickup with a 6.2 diesel. The truck has 200,000 miles on it and has always been dependable. About a week ago while driving down the road, it started making an awful noise, chatter, and blowing alot of white smoke. I had to drive it about a mile to my shop, all the while it did not lose oil pressure or get hot. I parked the truck, and assumed it was an injector issue, but about a week later I moved the thing, and a large puddle of oil was underneath. It has no visible holes, in the pan or anywhere else I can see, and still was holding good oil pressure. It almost looked like the rear main seal, but i'm not sure. The truck has never leaked any oil like that. The chatter sounds like it is coming from the top of the engine, on the passenger side, 1st or 2nd cylinder. Getting a mechanic to look at this engine where I live will be a chore so i'm kind of at a loss about what to do. I hate to junk the truck if it is something minor, and don't want to spend alot of money on a truck that old. FYI the injector pump was replaced approx 6mos ago. Any ideas? Thanks In Advance

Good possibility one or more of the rocker arms\shaft let go - pull the rocker cover(s) to check.
Requires moving injector pipes to clear - loosen and remove from injectors.

If that is the case, good possibility a valve(s) poked a hole in a piston(s) - that will require a compression check, cylinder per cylinder, and pulling the head(s).

In all actuality, those are both really bad possibilities, but the dictates of English grammar, and etc......well, you know.

On the brite side - that red '82 block is the high-nickel content block, suitable for re-building with power upgrades - 19:1 marine pistons, Tuf-trided balanced crank, 6.5L heads, injectors, DB2-4911 Inj Pump, '93 turbo and manifolds, etc.

Good for ~300hp @ 3500rpm

white smoke on gas engines normally indicates antifreeze not sure on a diesel, but you might want to check the head gasket.

Assuming you got the standard 12month warranty on your injection pump, I'd pull it off and send it in just to be checked again, tell them what happened and ask them to retest and if necessary repair the pump. If they find nothing wrong with it, send them the injectors.

White smoke means water is getting in the combustion chamber from a cracked cylinder head or head gasket leak. The 1982 head was notorius for cracks, but most could be repaired. I believe most of the cracks were at one end of the head. The intake manifold does not have a water passage thru it as the 350 did so it is not at fault. The first thing that I would do is run a compression check on the engine. A leaking head gasket would lose more pressure.

If the oil leak is coming from the bell housing then your rear main rope seal has probably failed. I would replace it with the 2 piece rubber seal (Fel Pro #BS409529). The oil pan gasket is Fel Pro # 0S34400. I wouldn't think about putting the Chev rope seal back in my engine. Also check the oil pump drive for leaks since the oil would also drain from the bell housing. The top seal (aluminum cap) on my oil pump drive failed a few years back.

Check your injectors, one stuck open will knock like a rod out and blow white smoke. The oil leak is entirely another issue.