81 240D Auto, god awful ringing racket at the front of engine.
 

I am looking at buying an 81 240d for my Dad as a replacement for his wrecked Honda. Trying to turn him to the dark (light?) side. At any rate. Car is in great condition with one exception, makes this god awful singing/jingling from the front of the engine at idle. Barely off idle it goes away. I was able to verify it wasn't the PS. PO says that the AC doesnt work and I noticed that the ALT belt was jumping at idle.

Any ideas? Water Pump? Vac? Again off idle goes away and purrs like a kitten.

Loose alternator fan would be my first guess.

My 240D used to make a ringing sound during acceleration from about 1500 to 2000 rpm (estimated). I never did find it. Eventually it stopped doing it. I was always suspicious of the alternator mounting bracket, but I never could actually pinpoint the source.

I had an AC compressor making a noise that could be described that way when I first purchased my white wagon. The clutch was just loose and near destroyed.....

I'll vote for a pulley with loose mounting nut)s)/bolt(s). I've seen idlers, ps, ac, alt, wp, pretty much any/all kinds of pulleys loose and rattling on their shafts, and they almost always make a ringing noise of one tone or another...

Check the altenator and it's mounting for loose, broken or missing bolts, including hollowed-out bolt holes in the alternator and mounting bracket. Check all the clips around the oil-pan that support the steel tranny cooler lines. Check the AC compressor and bracket for same as the alternator, and check the engine oil-cooler lines for any loose or missing support hardware, including the clamp & bolt that secures the lines to the AC compressor bracket. All these items needed attention on my '82 automatic 249D!

Happy Motoring, Mark

could be a siezing front crank bearing. I'd start taking the belts off.