Hi, I have a 2001 CL 713 with a EM7–300. The engine runs good however, it has a terrible intermittent squeak that resonates throughout the engine. The noise goes away sometimes for weeks Until recently it’s gotten a lot worse. Sound like it’s coming from the cam area #1 cylinder. Pulled the pan expecting to find metal but was clean. Pulled the EUPs and rollers all looked fine including guid pins and cam lobes. HRings all check ok. From underneath a couple intake and exhaust cam lobes Show some spalling and minor scratches but nothing chewed up.
Anybody have an idea what might be