1989 300E w124: I get a grinding, screeching sound whenever I change gears (P, Dr, R) - PeachParts Mercedes-Benz Forum

vexman2k3 · #1 08-08-2007, 02:25 PM

It makes this squealing sound whenever I apply the breaks too. I just replaced the brakes as well). The ABS break, and check engine light are lit as well, but not when I'm driving it.

Also, then I'm driving, I get this sound as if something is scraping against another. The sound comes from the engine. I'm guessing it has something to do with the transmission.

***Edit***

This scratching/scrapping sound increases as I gather speed.

There's also a little grinding and screeching whenever I turn the steering wheel. This only happens when it's in reverse, or drive.

vexman2k3 · #2 08-08-2007, 04:14 PM

Could anyone please help?

david s poole · #3 08-08-2007, 06:10 PM

check to see if the serpentine belt tensioner has gone bye bye and now you have a loose belt.

vexman2k3 · #4 08-08-2007, 06:32 PM

Where would that be located?

Also, are there any other possible causes for these irritating noises.

---
Also, I ONLY get this scratching/scrapping noise when the car is being driven. When it's on, but not in motion, I don't get the noise.

The steering wheel grinding/squealing noise occurs when it's in reverse or drive, even when I have the brake depressed and I'm obviously not moving.

The brakes squeal sometimes when I come to a stop.

I hope this helps.

brewtoo · #5 08-08-2007, 07:01 PM

Fan hitting the fan shroud?

vexman2k3 · #6 08-08-2007, 07:12 PM

Could be, but the sound hard gotten INCREASINGLY louder in the four days I've been driving it. It just went overboard today, and the steering turning squealing began. I'm too embarrassed to go anywhere. It sounds terrible.

Richard Wooldridge · #7 08-08-2007, 07:52 PM

I think David hit the nail on the head with the loose serpentine belt diagnosis. The serpentine belt is the wide flat belt that goes around the pulleys at the front of the engine. With the engine OFF, check the tension by pulling on the belt. It should be very taut. If you can twist the belt until it's up on edge, it's too loose. The belt tensioner is the most likely fix, but you could also have a defective belt. If the belt is loose, it will cause the alternator to slip on the belt whenever any electrical load is applied, like the headlights or brakelights. This will create quite a squealing sound. If the belt is loose, whenever you turn the steering wheel while the car is stopped will cause the power steering pump pulley to slip on the belt, causing quite a shriek or squealing sound. Should you turn on the climate control (heater/AC unit), the belt will surely slip on the compressor pulley, causing a loud shrieking noise. My daughter has a Range Rover that had the belt installed incorrectly, and whenever the lights were turned on the belt slipped on the alternator pulley and made an unbearable noise. In that case, all it took was a new belt installed correctly.

ps2cho · #8 08-08-2007, 07:54 PM

As for the squeeling brakes, you said you just got them replaced correct? It's very normal. You can either apply a thin layer of special brake anti-squeek grease (name?) or what I found with mine to help cure the problem faster is find a hill and go down it at about 40-50mph holding the brakes while holding the accelerator down at the same time. You should smell those brakes when you come to a stop! It really helped mine.

vexman2k3 · #9 08-08-2007, 08:15 PM

Richard, I just went out and pulled on the belt. It seems pretty tight. I mean, I could only pull it a few millimeters at best.

But I find the AC/Heater thing quite interesting though. Whenever I try to use the AC/Heater (which don't work at all), I get some loud shrieking sound, as if the fan is turning and sucking air but not producing anything. It's weird.

I think something just got tangled up and is touching something. That's why I might be getting these sounds. The steering grinding noise and trnsmission grinding noise might be a whole different case.

But anyone with anymore ideas please help.

vexman2k3 · #10 08-08-2007, 09:59 PM

Anyone else?

brewtoo · #11 08-08-2007, 10:23 PM

Quote:

Originally Posted by Richard Wooldridge

Should you turn on the climate control (heater/AC unit), the belt will surely slip on the compressor pulley, causing a loud shrieking noise.

If this happens, the compressor speed sensor will signal the discrepancy and shut down the compressor almost immediately.

Ferdman · #12 08-09-2007, 02:04 AM

Check if the fan is rubbing against the fan shroud. If so, you probably need to replace the engine mounts.

vexman2k3 · #13 08-09-2007, 08:06 AM

Alright, I'm going to take it to my work and see if they can check it out for me.