350 sounds like a diesel engine

[JBswth]

When you say "Sounds like a diesel", do you mean that it sounds like excessive clearance in the connecting rods? Loose piston pins? If the noise is right near the oil filter, I would check my connecting rods, starting with the rear-most rod. You could have one that overly large inserts for a larger size crank pin ie, your crank pins were reground .010 undersize, but one rod has a .030 undersize bearing. That excessive clearance will be audible if it is large enough. Also will cause a large amount of oil to drain out, potentially depriving the rest of your engine of adequate lubrication.

J. B.

Sorry, typo. I meant crank pins are .030 undersize, but one has a .010 undersize bearing. It will be too loose and might make noise.

 

[Ricko1966]

Sorry, typo. I meant crank pins are .030 undersize, but one has a .010 undersize bearing. It will be too loose and might make noise.

It won't have a .010 under bearing for long......That was meant to be funny. Seriously though if it has more than 1000 miles on it, I would very seriously doubt it's an undersized rod bearing,they usually hammer out paper thin quick and sound much much worse. And contrary to a popular belief you usually can't just put a new bearing in and go happily about your business. 90% percent of the time not only has the bearing flattened out the hammering makes the big end of the rod egg shaped so the new bearing fails soon as it hammers out of shape.

 

[Tom Weeks]

sounds like a broken flex plate vary common if you have a automatic transmission