Engine Problems

[Lights]

I started my S52 that I swapped recently and I am hearing a screeching noise that comes on after the engine starts to warm up. I confirmed its not any pulleys because when the screeching started I took off the belt and then started it briefly and heard the same noise. I used a stethoscope and it almost sounds like it could be coming from the bottom end but I cannot tell. Could it be a bearing maybe due to heat expanding it once it starts to warm up? I'm not sure if anyone has any knowledge that would be awesome.

I also notice that there is a ticking coming from the top end and think it could be the lifters ticking. I bought the engine used with 127k miles and it came with an aftermarket AMC head so it must of overheated at some point I just need to figure out what parts have been damaged. I took the valve cover off and can see some rainbow colors on the cams. I probably made a crucial mistake and did not prime the oil pump before starting it for the first time so it would make sense if I ruined the cams or lifters by doing that. I plan on fixing the top end but I am more concerned about the screeching noise that occurs about 4 minutes after starting.
I read that it could also be my injectors ticking and making loud noises? I did refurbished the injectors with new filters and caps.

[jbontke]

Did the engine run fine before you got it? Did you do any disassembly before the swap? I bought a trashed 99 M3 from a guy that sat in a field for years. It was full of water, animal feces, a live snake, and most wires were chewed on by mice. I started it (never changed the oil), no noise.