'87 300D-Turbo...whinning noise?

[khule-1]

...recent history - came to school and left car in NJ; harsh winter & mostly sat; would not start in spring; got it running and replaced radiator

I brought it down to VA last month and it drove just like I remembered (how beautiful). Now to my question, a friend borrowed it for a week (back up to PA) and I now hear a subtle whinning noise from 1st through 4th. I can feel a slight humming under my feet through the floor, and am wondering if this might be a transmission issue, etc...

May it simply be my tires wearing down?

I tend to get easily freaked by new noises as some have cost me a pretty penny...

[pkmaven]

The most common source of whining noise that changes pitch as one accelerates, is amplified alternator whine by the radio. It usually comes through the speakers. If it's the tranny, it might occur of one has not changed the tranny oil and filter in too long a time. The turbo definitely can produce a whine but most engine noises are not audible when the bottom cover shield is in place. P.

[khule-1]

...how do I determine which one it may be.

...well, its not the radio (currently not working).

...I can chage the tranny oil & filter (probably a good idea anyway). How much should this cost & any particular recommendations (or is all tranny fluid & filters the same).

...how can I teel if it is the turbo, and what do I do if it is?

[pkmaven]

The usual whining sound comes from the speakers even if the radio doesn't work. The speakers and tape/radio in a 16 year old 124.133 are garbage. When you remove the radio (very easy to do) to replace it with a CD head unit, remember to also replace the paper faced speakers with aftermarket coaxial speakers (also 4 ohms). If the whining pitch increases as you accelerate, it's alternator whine.

To change the transmission fluid (once/year), the car must be up on a lift. The fluid drains from the tranny first and then the torque converter in front. The converter must be rotated to allow the fluid to drain. Replace the rubber gasket at that time. P.

[AC_A340-500]

Check to make sure that the clutch fan (radiator cooling fan) hasn't seized up. That could cause a subtle humming sound.

[pkmaven]

Usually when the flex disks are shot one can hear droning vibration at cruising speed, or a clunk whe backing off on the gas pedal. P.