Mercedes SL Belt Squeal and Handover Issue

Belt squeal at that mileage is pretty common. Had a similar issue with my old Saab, though it was the water pump pulley causing the belt to jump, not the tensioner itself. Did you check the alignment of all the pulleys? Even slight misalignment can cause the belt to slip and squeal especially under load.

That's an interesting point about the pulley alignment. I hadn't considered that specifically. How exactly did you diagnose the water pump pulley as the root cause? And was your Saab's belt tensioner showing any signs of weakness or unusual movement at all? I am thinking about if replacing just the belt tensioner on my SL will actually resolve the belt handover problem.

My mechanic spotted the pulley wobble with a trained eye, I could not have seen it myself. The tensioner on the Saab looked fine, but the squeal was definitely coming from the pump area. If you're unsure, I'd recommend taking it to a trusted mechanic. Let them diagnose it properly. It could save you money in the long run.

Appreciate the insight regarding your Saab experience. You've convinced me. I'm scheduling an appointment with a reputable workshop to get a professional diagnosis. I'd rather spend a bit more on a correct diagnosis than throw parts at it and still have the belt squeal and handover issues. Thank you very much!