96 Siera

I've got a friend that recently purchased a 96 Sierra with a 3.1 engine from an elderly lady that was the only previos owner. Upon first inspection the car was clean as a pin inside and out, had only 55K miles on it and the engine "purred like a kitten" (his words). Engine compartment was clean and there was no signs of any leaks.

He lives in a different state from the owner so he paid a down payment and sent someone to pick up the car after he had sent the remainder of the money. The person that picked up the car called the next day to tell him the engine sounded like it was going to fly apart by the time it had been driven 5 miles to their house.

When we inspected the car the first thing we found was nearly a gallon of extra oil in the crankcase. When we drained the oil and pulled the filter we discovered that the inside of the oil filter was dry. Our theory is that the owner decided to get the oil changed and got a bad filter (check valve wouldn't open). When the engine started clattering because of lack of oil, oil was added until someone decided the noise was not going to stop.

All the noise seems to be coming from the top so we suspect there are bent pushrods (if applicable) or valve stems. Does anyone here have experience with this engine? Looks like a chore just to get the valve covers off. Anyone ever heard of an oil filter check vavle not working out of the box?

tia
Steve

Wow. Bad luck. I don't have much experience with this type of problem but the first place I'd check is the oil pump. Sounds to me like something is clogged or just plain inoperable.

Oh, I forgot to mention that the oil pressure light is operable (comes on when key is on) and goes out after cranking engine. Haven't actually hooked a gauge up yet but there is evidently some oil pressure which makes one think the pump is OK.