A Klasse hybrid engine noise issue

Strange engine noise on my 2019 Mercedes A Klasse hybrid, currently at 50453 km. The belt handover doesn't seem to be working right. I suspect a defective belt bringer or handover. Has anyone else run into this? Could it be the timing belt or tensioner pulley? I'm also worried about possible serpentine belt problems and what it means for car upkeep.

4 comment(s)

I've got a similar A Klasse hybrid. I had a similar issue, and it turned out to be the belt tensioner. Is the noise constant, or does it change as the engine speeds up? A bad tensioner pulley can definitely mess with belt handover.

Thanks for the quick response. The noise is louder at lower engine speeds, almost a rhythmic squeak. Did you swap out the whole tensioner assembly, or just the tensioner pulley?

I had to replace the whole tensioner assembly. With what you're describing, plus the belt handover problem, I'd really recommend getting the tensioner and serpentine belt checked out by a shop. Better to be safe.

Thanks for the advice. I took it to a shop, and you nailed it. The whole belt tensioner needed to be replaced. The repair was 455€. Thanks again for the help!

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