I'm getting this odd rumbling from about 30 mph through 50 mph in my 300TD
Turbo. It may have always done this since I got the car, but I haven't
noticed it as much until lately because it's gotten cooler outside and I've
been keeping the windows up and the roof closed.
Along with it is a sort of 'pulsing' vibration. It's similar to what you
would feel and hear if you were driving something with about 400 HP with
headers and turbo mufflers. It has plenty of power and I've changed the fuel
The actual ride is smooth, but there's this pesky vibration.
I want to think it's nothing more than the prop shaft bearing, but now and
then I get the sense it's coming from the engine or transmission. It doesn't
seem to get any worse or better when accelerating or decelerating, but seems
to be worse when crusing at around 50 mph.
It's very noticeable when you accelerate to your desired speed and then back
off the throttle to maintain that speed.