Yep,,,, I stopped by Harbor Freight and bought a new stethascope.
Car was knocking like crazy at idle at stop lights.
Wanted to make sure it was an injector or the vac pump or whatever.

So drive home shut off car unwrapped new steth and restarted car.

No knock,,,,,heck smooootttthhh.

Drive to work today smootthh, cruise control started working, sun roof not as noisey.

I think it was afraid I was going to check its tail pipe.

Honest a miracle,,, or was it the "gallon" of Lucas injector treatment put into 10 gallons of fuel 2 tanks ago???

Weird,, this cars is weird.

Dave

Weird is the operative word. The 77 300d sounded really bad towards the rear of the engine. Noise dissapeared with no intervention at all.
It really sounded serious at the time. I guess not really unknown on the 616 and 617 engines. I never remember anything like this on any gas engine in the past.
Exception being a piece of carbon breaking loose perhaps is all I can remember. I was just basically happy the noise went away and never resurfaced with this type of thing.