Mysterious engine knock :-(

[ItsGKtime]

I bought this 99 B3000 with no oil pressure. Dirt cheap. Sounded horrible. So i had a pretty good idea what i was getting into. The diagnosis wasn't to bad (for working on imports for a living lol), the camshaft synchronizer gear teeth were ground down to nothing, obviously the oil pump wasn't turning either. So I put a new synchronizer and oil pump in it, engine runs smooth, excellent oil pressure, but the engine is knocking, sounds EXACTLY like rod knock. OK i'm thinking it's still not a tragedy (the price was right) so i tear down the engine the second time, put a set of rod bearings and a set of hydraulic lifters in (some of them felt really weak). After starting up the exact same noise. Sounds just like rod knock but a little quieter. Gets loud under load, almost disappears at idle. I'm thinking my last resort would be a knocking wrist pin but before i tear it down the 3d time I thought i'll ask around if anyone had similar problems.

 

[fordwheelinman]

Did you check to see if you had any cracked pistons?

 

[Jordan94]

I had the same problem and it was the crank bearings, you could move the crank up and down with lots of play, created the pistons to hit the head and basicaly screwed my motor. But that is like worst case senerio, distubuter problems leads to knock, look around, maybe a callipsed lifter.

 

[martin]

If you have good oil pressure it sounds like wrist pins. Anything on the pressurised side of the oiling system would cause a drop in oil pressure.