As i've read the rpm's on this model run
high at higher speeds. Is it normal to hear
a high pitch whining noise when I go above
70 mph? The engine sounds smooth as silk till
i get over 70, and that whining starts. I
assume it's just because of high rpm?
Thanks
81 300D
242K miles

A good way to determine if it is engine noise or otherwise would be to carefully shift to neutral and let the engine idle while you're above seventy. However, I wouldn't put it back into drive at that speed, I'd coast to a near stop before putting it back into drive, just to be on the safe side.

If the noise goes away it's in the engine. If the noise is elsewhere, you'll still hear it, and without the engine noise, it might even be more apparent where it's coming from.

Good luck,

------------------
Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

If the noise does not occur in coast at 70 MPH it could also be drivetrain related as the drivetrain is not being driven when in nuetral. Possibly trans, rear, bearings. Coming from an old Jeep I have found that different sounds occur in coast and driven situations. My bet...some bearing.
If you wait it will get easier to diagnose.
You do have a cell phone, right?
Good luck!

Thanks Zach and Larry.

I will try this and let you know what happens. I hope all is ok, because I'm
going on a 1000 mile trip tomorrow.

Another thing I noticed is that I hear and feel a distinct "clunk" under the car when I put on brake just before I come to a stop.
havn't been able to pinpoint exactly where
it's coming from yet. Any ideas on that
I'd appreciate it. Think i'll go ahead and post that as a new topic also.Thanks

Phill,

The clunk could be anything from a bottle rolling around to suspension components. If you're sure there's nothing loose and rolling around, I would raise the car and start shaking things and maybe prying around with a bar to see what's loose.

Good luck,


------------------
Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Thanks Larry,

I took everything out of trunk that might cause the noise. I did check underneath, but just looked at it visually, need to do a little shaking and prying like you said.
If you never hear from again, you'll know the trip wasn't a success
Phill