I'll bet you dime to a dollar that the Timing Belt Tensioner is on the way out.

Replace it ! Don't screw around. My '86 740 Turbo did the same thing. You maybe have baked and thrown some of the ball bearings in the tensioner assembly, you need to make sure that you take off the lower dust cover - that means you MUST pull off the Crank Pulley. Make sure you inspect that cover and make damn sure there is NO, ZERO, NADA, shrapnel inside that lower cover OR behind the crank pulley BEFORE you reassemble all the parts. You will be fornicating yourself with a large long device of some sort if you don't replace that tensioner. It could be very painful and I would suggest you take me seriously.

You are already there, so don't bypass this step, you'll be sorry if you do and I am speaking from experience. If there is ANY shrapnel in there (bearings) and you put that back together without cleaning and inspecting you are going to be in for a huge PITA !

You can call me if you send me an email - we are neighbors, or I can call you if you send an email with your phone but, DON'T screw with this ! Trust me.

Abe Lincoln said it was a smart man who learned from his own mistakes - only a genius could learn from someone else's..........

Cousin John
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'92 740 B230F Wagon::'92 B230F 240::'86 B230FT Wagon (RIP-Parts Car):'83 320I::'79 320I::'81 320I::'74 2002::'70 Torino GT Convertible(351C)::1970 Dodge Dart GT 340::'70 Monte Carlo::1979 Dodge Tradesman B300 Custom(360)::'84 SAAB 900S::2004 Dodge Dakota