Metal On Metal Squeal on 300e

Hi,

I have a 1990 300e that has an intermittent problem.
From time to time, I get a metal-on-metal squeal from the left side fo the car. It goes away immediately when I tap the brakes.
Sometimes it returns immediately and at other times, it takes a few minutes. Any ideas?

Also, the car idles roughly. I just had the cap, rotor and wires done with no change. The mechanic tells me it's not the idle control valve ( I have one ) but that it might be injectors. That sounds expensive. Is there a good way to clean them?

I live in CA and use Chevron gas and put Techron in from time to time.

Thanks,

Richard

[ymsin]

I have the same squeal too (I think), when the car has been running hot. Its on the left side and intermittent. Thought it was sorted out with new discs and pads.

Does the squeal come on when its running hot too?

You are right, it doesn't happen when the car is cold, only after about 20-30 minutes of running time. It's strange!

Richard

[d2bernhard]

I had this too, then it got really bad, all the time. I thought for sure it was the front, but had my stalwart co-tech (wife) stand outside while I slowly drove by the house. It was the rear. Wheel bearing and Hub need replacement. Brakes and E-Brake shoes got done too at the same time as they were shot. This on the ‘86 300E with157k.

[goldstone]

See the following thread that I started a few days ago:

Please! Help kill the mouse under my 1989 420SEL

Seems like we're all having the same problem!

David, did replacing the bearing and hub actually fix the problem for you? Or do you still have the squeal DESPITE the repair work? (It wasn't clear from your posting.)

I ruled out the brakes as the cause, since I had mine done (rotors, pads, and calipers), and it made no difference: The whining persisted.

If indeed the bearing/hub replacement solved the problem, may I ask if it was an expensive fix?

Thanks for responding...

[d2bernhard]

My squeal is fixed. As well as some of my handling problem (the rest will only get fixed by the suspension rubber replacement). My brake rotor moved a cm in and out (toward the diff) on the one side. I have a trusty mechanic who usually does VW. He was reluctant, but agreed. He said it's all the same as a VW as far as rear bearing and hub.
So here's the list (all rear) (All parts OEM, except Hub which is OE and was only $2 more than OEM):
1 hub
1 bearing
2 rotors, Balo
4 pads Textar yellow box
4 EBrake Shoes, Lemforder I think
$550 parts and labor

[ymsin]

Originally posted by d2bernhard
My brake rotor moved a cm in and out (toward the diff) on the one side.

I assume that was the cause of the squeal? If so, was the rotor movement very prominent to the extent that you could actually move it (wriggle it)?

[csnow]

Richard may want to eliminate more mainstream problems first.
Brake squeal is a fairly common problem, where bearings tend to last a very long time.

[d2bernhard]

I don't know what two pieces of metal were rubbing. The rotor movement was independant of caliper and wheel carrier. From everything I've learned here and other sources, that's a bearing.

Hello Everyone,

Thanks for the input. It needs an oil change soon, while I have it in, I'll have them check the wheel bearing. Hopefully, that is the problem. Tha car does have 140K on the clock, so it just might be time for one of them to go.

Best Regards,

Richard

[ymsin]

Had the weekend where the 126 made an appointment at the garage where they were taken to task in locating the squealer.

They checked the dics to the bearings and finally had a look at the rear hand brake shoe (which had a lot of dust and dirt). They zeroed in on the brake shoe and removed it to clean it through and through. It seems that solved the squeling, for now ...