I've been chasing a squeal at startup on my 93 300e 2.8 for way too long now. New belt, new tensioner, new idler pulley, and I still get a horrendous squeal for the first couple of minutes. I've disconnected the air pump clutch leads, and I think I've isolated it finally to the air pump clutch itself. When disengaged the outer pully rotates around the inner clutch, and I think I have some sort of interference there until things get toasty. I want to remove the air pump and run it without it for a few days to really isolate it as I'm tired of routinely replacing every single rotating part.

So, does anyone have experience with running a M104 engine without the air pump? Any idea what length belt would then be needed?