Noisy w124: please help

[e36bob]

Could anyone help me with a w124 230 te estate.
I can hear a droning noise from the front of the car. The noise becomes intrusive above 60mph.
The car has 143,000 on the clock, but as there is no service history, the mileage cannot be verified.
I have spun all the wheels, there is no play on the bearings, and no obvious noise either.
My previous car , an Audi 90 , suffered the same, until I replaced both rear wheel bearings.
I have looked underneath, and the rear driveshafts look okay, and all cv boots are intact.
All brake pads and discs are okay.
This work on the merc will cost a lot more, so I need to find out if there is a way of determining where the noise is coming from.
The auto box changes smoothly, and the engine is quiet, with good acceleration.
I hope someone can shed some light on this, as it is spoiling a nice car.
Thanks for any replies.

 

[joe bloggs]

Need to know if the noise is engine speed, or road speed related, knock it into neutral briefly (careful, not reverse), does the noise go away?, does it alter when turning corners (loading the wheel bearings)

 

[Terminator]

First of all check that the splash guards behind your front discs are not making contact with the discs. If so prize away. If this is not the cause of the problem and having eliminated play in your front bearings I suggest you check the following:

I would recommend you check and replace if necessary the following, having eliminated worn front wheel bearings:

1/ Check to see whether front brake calipers have seized.
2/ Worn anti roll bar bushes.
3/ Front propshaft coupling (prone to wear).
4/ Steering damper.
5/ Check tracking and suspension geometry.
6/ Check condition of coil springs and shock absorbers.

Good Luck!

 

[tom7035]

Sounds like a straight-forward front wheel bearing job? (Not expensive if you're doing the job yourself).

 

[davidsl500]

Has similar sort of noise on my Sl which turned out to be a nearside front wheel bearing. No noticeable play - 3 weeks ealier it had sailed through the M.O.T

 

[tom7035]

Further to my post above, if you are doing the job yourself, a way to cut costs even more is to buy the bearings from an independent bearing vendor, although you would have to give them the bearing no. from your old ones. (Not MB part number, but the number stamped on the actual outer race of the bearing). A fraction of the cost of MB boxed part and still a quality bearing such as Skefco or FAG etc. You would need to buy the grease seals from Merc separately. Also of course you'd have to be able to have the car offroad a little longer during the process of acquiring bearings independently.

For what it's worth.

Cheers, Tom.

 

[190]

try www.eurocarparts.com they will cost you less than £20 a side including the seal. Very easy to fit.

 

[tom7035]

Yes 190, seems a very fair price. Would save the car being offroaded for more than the fitting time too.

 

[e36bob]

noisy w124 please help

Thanks to all for the replies.
I took the car to star motors in reading, and the car was road tested.
The technician listened whilst driving the car, and said the engine, box, and diff were ok.But, noticed the tyres were of foreign produce, which he said might be the reason.
Since the tyres were worn anyway, I replaced all four with pirellis.
The noise is still there, but has dropped to an acceptable level, so the tyre theory was correct to a degree.
I am reluctant to drop the auto box into neutral at motorway speeds, so I will follow the concensus concerning the front wheel bearings, and replace both, which I can do myself.
Thanks again for the replies.

 

[e36bob]

noisy w124 please help

Took the car to seventy mph, with the drone in full flow. and slipped the box into neutral, and no gas on the pedal.
Noise dissapeared completely,suggesting no wheel bearing or rear axle drone etc.
Back to square one.
Whilst at idle form test, I blipped the throttle hard a few times, and heard
some noise from the exhaust system, which sounded like resonance, coming from the central are of the car although the drone sounds to come from the front of the car.

Any ideas anyone.

 

[OlafMaxwell]

Exhausts do sometimes disintegrate inside the silencer but I have not seen that for a while. We used do a job on them when we had motorbikes to make them more powerful by increasing resonance. However the noise side effects were a bit extreme. Seems wheel bearings etc all ok.....CV on front wheel drive occasionally did that to us.

How about the underbody shields, though this would still make noise in neutral if it were loose......only other thing is an engine speed related malfunction.......bearing /water pump? alternator? fan? underbody shield vibrating off exhaust [one under the transmission?]

 

[turnipsock]

I have had a noticable drone on my 230TE as well. I have recently had my box done and the drone is still there.

Prior to this I thought it was the prop shaft and replaced the centre bearing (there is a thread about it somewhere).

I wouldn't eliminate your running gear just because the noise disappears when you stick it in neutral. When in neutral it's still going round but there isn't any load on it.

The 'expert' that did my gearbox, thought it was the diff...even though the noise sounds like it is coming from the front somewhere.

I have also replaced a wheel bearing recently, that was a different sort of noise.

Within the last 5000 miles I have replaced the complete exhast, the anti roll bar bushes and a spring. I have also replaced the oil with a synthetic type. The drone is still the same.

 

[Bolide]

Droning on...

If the noise is a speed-related drone, and it has a single cause, it's related to something that turns at roadwheel speed. So it has to be:

* gearbox
* prop
* diff
* rear driveshafts
* wheel bearings

If the car has 143k and no history it's either got 143k or 250k+. Based on that I'd suspect the diff is worn

If the noise goes in neutral at speed it may well be gearbox-related. The prop will still be rotating at road speed (as will the rear driveshafts, front & rear wheelbearings, etc) but the engine will be at idle and part of the auto box will be running at idle speed. But there will be little load on the diff when in neutral at speed so I don't think it's a conclusive test. What happens when you come on & off the throttle at speed? Does the noise change?

Did Star put the car on a ramp and give it a good look over? The state of the underside, brakes and suspension will give a good indication as to the general condition of the car


Nick Froome
http://www.w124.co.uk

 

[TheJim]

One possibility is the cat is breaking down- mine is at the moment. The heat shield had been damaged and so the red hot cat had come in to contact with cold water from puddles. Death to a cat apparently. So mine now resonates when the car is at about 1900 RPM. It also rattles when I go over bumps.
I don't know how you can confirm this. With me it is more a process of elimination than anything else.
Good luck.

 

[turnipsock]

...except, I don't think my car has a cat :???:

I'm not sure about e36bob 's, I guess his name is his reg number, so his won't have one either.

 

[TheJim]

As I found with mine, cats were fitted on some cars going back to late 89.
Bugger only knows why.

 

[e36bob]

noisy w124 please help

Thanks for all the recent replies.
I have noticed that the engine does produce a small amount of vibration at idle, and blipping the throttle seems to increase the level.
I checked the engine mounts, and both are okay.
The engine has been retuned to use unleaded according to a sticker on the front engine bay cross member.so I will check the ignition timing tommorrow.
I listened to the various pumps etc, and only the power steering unit was noisy, but my wifes E36 unit is noisy too, and she doesnt get the drone.
The camshaft noise is very slightly noisier than what I would expect from 145000 miles, so maybe this is part of the problem too.
I rechecked under the car, exhaust seems fine, no leaks, checked both front wheels, again nothing obvious.
I will change the front wheel bearings soon, as I can do that myself, so the process of elimination continues.
Is this problem particular to the w124 class only ?
Thanks again for all the replies.
Bob

 

[e36bob]

noisy w124 please help

Bolide,
I forgot to answer your questions, sorry.
Star motors didnt have the car up on the ramps.
I have checked underneath her as best as I could, but until I see her on the ramps, I cant really form an opinion.
As far as the mileage goes, without history, she might have been to the moon and back, although she has only used a minute amount of oil in 2,500 miles I have driven.
The drone does reduce when the throttle is backed off, and resumes when the gas is reapplied.
Thanks for the replies.
Bob

 

[mike65]

I took the car to star motors in reading, and the car was road tested.
The technician listened whilst driving the car, and said the engine, box, and diff were ok.But, noticed the tyres were of foreign produce, which he said might be the reason.

Since the tyres were worn anyway, I replaced all four with pirellis.

Foreign tyres to blame ?????? Heard it all now. Pirelli is Italian.

Mike.

 

[tom7035]

Just a thought re. this elusive drone. I'm no Merc expert but I'm sure I read somewhere about OE exhaust downpipes being double skinned. Might it not be a cheap aftermarket non-Merc pipe has been fitted sometime which could be responsible for this?