I have this weird knocking kind of clapping sound coming from the engine compartment. At first it was quite could not hear it in the engine compartment, only from the driver’s seat in the truck. Engine was just rebuilt 3000 miles ago. So I checked the valves, all were tight reset to .010” I & .020” E, and re-torqued converter bolts, checked all line dampers. Was quite no noise the first day. Next day I noticed a puddle of oil under truck, and it started making the noise again. Well oil came from valve cover gasket out of place, had to drive it a few days that way. Got it fixed re-checked all valves since I was in there all good. Now it is making more noise than before very loud. Coming from drivers side. It is the loudest under the truck, about under the drives seat. Sent oil sample off, it came back lab said all was normal. I cut the oil filter apart, and there are some sparkly flakes in it, looks like aluminum, not magnetic. This is odd since oil test lab says no aluminum in oil. I am thinking maybe transmission, it does not make as much noise once it goes into lock up. So needless to say I am baffled. Maybe I should sent transmission oil off to be tested? Any advice where to start checking next would be great.

 

How's oil pressure? So you rechecked all the valves?
Sounds like a loose valve maybe a valve seat?

 

oil pressure is very good. Yes I reset all the valves, and checked them all again a week later, all are good. Head was just rebuilt, with the rest of the engine about 3000 miles ago. If a seat was loose would not one of the valves be tighter than the rest???

 

might could be a loose seat but with aluminum in the oil theres something goin on with a piston. maybe a piston cooling nozzle is stopped up on one cylinder and youre hearing the wrist pin knocking. Get a scan tool and shut off the injectors one by one and see if the noise goes away on a certain cylinder.

 

would I be able to just pull the wire connector on each pair of injectors to get a general idea if it is something in the cylinder or injector???

 

that would narrow it down to a pair of cylinders but would isolate one single cylinder. I don't think its injector prob. by shutting off the injector youd be taking the load of the cylinder and the knock/clap should clear out when you shut off the right one.

 

I am just going to pull the wires and see if it makes any difference, if it does then I will at least know where to start.

 

well pulled the wires on the paired injectors, the noise was still there. Still find it odd there were small metal particles in the filter but nothing showed up on the oil test.

 

could you have got your egts too hot and scored a piston.

 

Take all the convertor bolts out. And see if it is still making noise If it is you know it's not a trans problem