When my '81 W123 240D is thoroughly warmed up (not when it's first started) there is a intermittent clicking or chirping noise coming from the area of the alternator. If you squirt water directly on the alternator belt the noise will stop until the belt dries off. So, I replaced the alternator and still have the noise. The belt looks good and I replaced the water pump about a year ago. Those are the only things running off that belt. Any theories? Thanks.

Chirping is usually a slipping belt... might've tightened or replaced before buying a new alternator.

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1981 240D 4sp manual. Ivory White.

There is a product called “belt grip”. Re-adjust the belt and apply belt grip to the belt.

I can't imagine why you would spend the $$$ for an alternator and keep the old belt. I would replace the belt - if you spray it with water and the chirp goes away, it can only be a bad belt or a bent pulley.

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Milan Brown 1979 240D, rebuilt OM617.952 turbo diesel, rebuilt 722.315 transmission (my only daily driver)

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