Scratching my head here. Purchased a 2001 GMC Topkick with cat 3126b with huei system. Little known about it. After a new starter relay and IPR valve (Old one was bent), she runs. Loud knock coming from what sounds like Cyl 1 or cyl 2 mid way up. Have engine torn down and all three inspection plates off. All 3 sets of followers look great as well as camshaft looks great, no play. Felt on rockers while running and they all felt tight, all same adjustment. No bent pushrods. I have brass or bronze looking fine metal in pleats oil filter. Pics attached. Any ideas of where to look for the metal coming from? What's brass or bronze in the engine that would give off loud knock? Engine seems to idle fine so I don't thinks it's injector related, but I dunno. Please help!
Could the “brass or bronze” possibly be copper.? If so there is a copper layer directly under the lead-tin overlay of the main & rod bearings and also in the wrist pin bushes.
I would drop the oilpan and check the rod bearings and then the mains. If a main bearing spun, it may have choked off the oil supply to a rod bearing. Also check the crankshaft thrust bearing
Only three places that would make that much copper, crank, cam, rod bushings. That's allot of material--whole engine should be loose as a goose, should have rev'd nice.
Heres what I got so far with Rod 1 and 2 off. Trashed crank on 2 and look at the discoloration of the crank by the mains and rods. I haven't got to the mains yet, but if they aren't trashed do you think this crank is good for a machine shop grind?
Rod 2 bearings. They were spinning
A discussion over a 3126 recently--about buying a used or reman. Depends on your wallet & time frame if your thinking about rebuilding. Figure the going price of the three options, and how much it will be used. This is a area that only the owner can decide, it's your money either way.
There seems to be more available C7 Cranks and rods vs 3126. Yes I'm referring to Ebay as my application for this engine is to get it going in a C7500 Kodiak I recently got for a work truck, so not crucial I buy the best money can get. That being said, are the internals the same on the 3126bs and Es and the C7s?