Can anybody give me an idea of where to go on this? I get an intermitent load squealing noise a little above idle. At just above idle it continues until the rpms are up and then it stops. It is definitely belt related or pulley or tensioner or ? I'm new to this posting/ forum but have been lurking for years. My $500, 79 300D's first problem in 2 years since I bought it.

Is your alternator belt tight?

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

As Tom asked. Usually the issue with your description. A quick test is see if you can turn the alternator pulley by hand with the engine off. I usually use the external alternator fan blades to increase leverage a little. If so the belt is is quite loose.
If a case ever arises where you are not sure just rubbing a little bar soap on the belt in the v areas of it will shut it up temporarily. It acts like a belt dressing.
This is only to make sure if the standard test leaves you wondering. Again needless to say rub the soap on the belt with the engine off. This is good to increase belt traction for awhile if you are on a trip as well and develop slipping belt syndrome.
To stop this kind of occurance develop a program to check things like condition of belts and belt tension say once a year.
Only the serpentine belt system can be semi ignored and even they must be checked for excessive cracking and wear. Because their tension is automatically adjusted the alternator for example will never squeel. The downside is they usually just break at some point if not inspected periodically.
I believe it really pays to go over a car doing all the little things like lubrication of door hinges, Hood hinges on some type of schedule. For example if you have not lubricated your hood hinge pivot points find them and do them soon. Otherwise the hinge pin can seize and becomes a miserable job to repair. So bad you will never ignore it a second time. So many problems are just so easy to avoid. In a couple of hours once a year catches many things early. Remember the valves need clearance checked every 15k miles. This is an important item in my opinion.

I had the AC compressor freeze up on me and cause the same thing. It was momentary the first time but the second time there was no doubt as it smoked the belt right off.

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1977 300D Lost coolant while someone else was driving
1983 300D Can't run without oil
1985 300SD (gone but not forgotten)
1990 300TE 4matic Sold
1991 Yamaha Venture
1975 Kawsaki 250 triple
1974 Honda 200CL
1951 8N Ford
2008 Wildfire 650C

Thanks Tom W:

That's exactly what it was, loose alt. belt.

Great! a simple fix.

Tom W

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.