Wailing noise from center of dash
 

Hi everyone,

I'll get to my question in a second, but first a word of thanks.

A couple weeks ago, I decided that I wanted to buy an old diesel Mercedes. I began researching them on the web because I'd never even been in a Mercedes before. I didn't know what the different model numbers meant or what I should be looking for. During my search, I came across this forum and it has been fantastic. So thanks to all of you for the knowledge you've provided me - before I even have a Mercedes. Not only that, but reading these posts took me from considering an old Mercedes to I-will-buy-nothing-other-than-an-old-Mercedes status.

Ok, now for the question. I think I have found my car. It's a 1980 240d and is in great shape. I test drove it this morning and it ran great, but it makes a loud whistling/shrieking/wailing-like-a-banshee noise. It only makes the noise when the car is moving and it's doesn't seem to be tied to the engine. If I rev the engine or put it in neutral as I'm moving along, the noise does not change. When at a stop and idling, there is no noise. It sounds like it's coming from the center of the dash, possibly through the center vents. I think I closed them by sliding that mysterious lever, but it had no effect on the noise. I tried all combinations of the climate controls and it had no effect on the noise. Even if the fan was completely off, the noise was still present. My best guess is that it is wind noise somehow making it into the car. But it's extremely loud. It varies in pitch and stops every once in awhile (while moving). I've scanned this forum for over an hour and can't find any other mention of this particular noise. Any thoughts are greatly appreciated.

Thanks,
Flop

My car does that, too, but it needs door and window seals replaced. If I'm going 50 mph or less, its not bad, unless I hit a strong head wind, or a strong gust from the side hits.

Try cracking a window and see what happens.

your odometer and speedometer could be making the noise. Mine did that/Tom

i kinda have the same thing, i hear a wisteling noise coming from the climate control area, i think it may be a vac leak

Ghost.

























:D

Seriously, I would also take a look at the spedo. Mine howls like a banshee when it is cold.

Seat belt warning buzzer maybe?
It makes a horrible noise to me.

Louis.

I've got something sorta like that too, only it only does it every now and again. It started right after I replaced the ignition switch (and had the instrument cluster out). I guess this may be why? I'll look up about dealing with the speedo/odo I guess.

Thanks for the suggestions. How would I determine if the speedometer cable is the cause?

mine did that same thing yesterday but it was only over 60 mph and it was about 25 outside

I'm not absoultely sure that it applies in this case, but in some vehicles you can lubricate the speedo cable, and possibly use a light lubricant on the gearing of the speedo, if you can see it.
In this case, I think I'd try spraying some cable lubricant down the cable from the end at the back of the speedo, and see if it quiets down.

In the motorcycle communities, another solution to stiff cables is to fasten a small funnel to the upper end of a cable and put a little light weight oil in it, allowing gravity to work the oil in over a period of time. It seems to work well, but can be messy, if you don't want the oil coming out at the other end.

Update on the wailing banshee noise.....

I ended up buying the car. The banshee noise started up as I started moving. It really did sound like a very loud ghost. About 20 minutes into the drive home, the sound stop and has not returned. I took the car out a couple times later in the day and no wailing banshee. I'm not complaining, but am still curious to know what it was/is.

since it stopped, it may have been polterguists... they stayed at home...









anyway, it looks like the speedo cable warmed up and it's quiet now.
I would reach up behind the dash, and pull the speedo cable out and put some oil in it like the above post said.
John
Oh, and Welcome to the forum as a certified Mercedes owner!
I hope you don't end up like me and fill your yard with 6 of them for no apparent reason...
John

Thanks for the welcome.....and for the warning about stockpiling. I have to admit that that is in my blood. I'm an avid cyclist and have somehow managed to amass 9 bicycles. I can fully explain a need for up to 5, but 9 indicates I have a problem. And I do already have my eye on another Mercedes I've seen. Luckily, my driveway will only hold 3 cars, I have no front yard, and a fence prevents cars from entering my backyard (at least it does at the moment).

I started collecting bicycles long before I got hooked on diesel Mercedes. I can no longer fit anymore bicycles into my basement nor anymore cars into my driveway... I was looking for a car storage place yesterday.

I gotta take an overhead pic of my estate of cars... something like 26 in the yard..."hello, My name is John Sheridan, and I am an autoaholic"...
I am really glad that I got into MB's they are SO much easier to work on, and the ride and Brakes are phenomenal.
John