1989 Chevy truck. Newly rebuilt motor now has loud knocking noise

[julie10]

1989 Chevy truck (350 motor...4 wheel drive). Newly rebuilt motor now has loud knocking noise. Mechanic says oil filter may have collapsed. He's still investigating. I read where a collapsed oil filter is usually the result of an internal engine problem. Could be from a sticky filter bypass or a sticky oil pump pressure regulator. I'm thinking the loud knocking noise means it has a damaged piston or damaged connecting rod or mainshaft bearings because of an oil flow problem. Does anyone have any suggestions on what to check next or anyone have this problem before? Help!

 

[chopped39]

Pull the pan and inspect. I have had a couple bypass stick but it blew the oil filter gasket out. Is the mechanic the one that put the engine in? If so bring someone that knows engines with so you dont get some bs story. how many miles on it? Was the oil pickup welded to pump? If not it probably fell off. If so its done.

 

[julie10]

Not sure about the oil pickup welded to pump. I'll have to check on that. Different mechanic is trying to find the problem. The new motor has around 100 miles or less on it. I do know that the oil was black and the mechanic found some clumps in it. Even found some small metal shavings. The oil was just changed a month ago after installing a new oil sending unit. Didn't change the filter because a new filter and new oil was added just after the motor was rebuilt 3 months ago and the truck hasn't been driven very far.

 

[chopped39]

Yank the pan. Who rebuilt the engine?

 

[julie10]

I'm sure he will pull the oil pan off. The man that rebuilt the engine is a good friend of mine. He's a machinist, works on cars and does body work in his spare time. Talented guy. But something has definitly gone wrong with this project.

 

[regan j]

I hope the guy that rebuilt the engine has knowledge of what is going on so that when you do let him know he wont be blindsided and get defensive. Hope this works out well for you.

 

[julie10]

regan, j...The guy that rebuilt the engine knows all about it but hasn't had time to work on it yet. One thing the other shade tree mechanic found is that the main bolt to the harmonic balance was stripped. That is fixed now but still have knocking noise. He thinks the bottom of the motor will have to be rebuilt and will need a new crank shaft.