Pulley bearing failing

[996jimbo]

I've got a nasty noise coming from the front of the engine which at worst is a pulsing screeching and at best is a pulsing (light) grinding. Sounds like a pulley bearing failing. Took it to the garage and they reckon probably idle pulley bearing but not sure.

Contenders I guess are alternator (unlikely?), power steering, water pump (no losses or cooling probs though), A/c compressor, idle pulley (is there more than one?), errr, can't think of anything else.

My question therefore:

1. Anyone had bearing failure on a pulley running off the fan belt? If so which one?

2. What kind of bill will I be looking at (big, obviously (!), but just how enourmous)?

3. Anyone got a spare car for 3 days as the garage can't look at it 'till Tuesday!

Car's a C43 by the way.

Cheers,
Jim

 

[Andy W]

My last car a W202 C180 used to squeal like a pig as soon as you engaged gear but once you were moving it stopped but once stopped and still in drive or reverse it would emitt an high pitched squeal. I removed the auxillary belt so that I could check the water pump, air con pulley, power steering pump and auxillary belt tensioner. I noticed that the water pump pulley had collapsed bearings and was rough when you spun it by hand and there was a lot of up and down pulley movement as well. I replaced the water pump which cost me £55 and the noise was still there. Further investigation with a screw driver convinced me it was the auxillary belt tensioner. I obtained a new one, fitted it and it cured the noise. On my car it had the old type tensioner which did not have a shock absorber to dampen the pulley body so I had to purchase the 2 items, I think the total bill came to about £95 for the parts and I fitted them myself, quite easy to do actually.

 

[996jimbo]

I've had a long peer at it. There's not a lot of room to see what's going on but it appears that the belt is being deflected back slightly to the rear of the idle pulley by the crank pulley and consequently is rubbing on some engine casing.

The crank pulley appears to have a sleeve/guide around it for the belt. Can anyone give me any more detail about the crank pulley? I've found some lumps of rubber under the bonnet and was wondering if the rubber is (was) a bush for the crank pulley?

 

[normanr]

Hi jimbo

I just love those nanas

:bannana: :bannana: :bannana: :bannana: :bannana: :bannana:

 

[996jimbo]

Hi jimbo

I just love those nanas

:bannana: :bannana: :bannana: :bannana: :bannana: :bannana:

Ah, but now they've stopped moving!


Doh! Logged off and back on again and they're doing their silly dance!

 

[996jimbo]

Slight update: the belt is misaligned on the fan, the idle pulley and the crank but back in line on the a/c compressor (I assume that is the one that comes after the crank). The crank appears to be the only pulley that can cause the misalignment being a flanged pulley so am pretty sure that is the culprit.

Would therefore still appreciate if anyone can describe the make-up of the crank pulley.

Thanks.

 

[grober]

POSSIBLY CRANKSHAFT DAMPER FAILURE COMMON FAULT. If it lets go at speed it can damage the sump and timing gearcase= big bucks. Relatively cheap to fix at moment if its that. see http://mbclub.co.uk/forums/showthread.php?t=28288&highlight=CRANKSHAFT+DAMPER

 

[Dieselman]

The crank pulleys are dual mass pulleys and it sounds like yours is collapsing. The pulley can wreck the chain casing if left so deal with it soon.

 

[996jimbo]

Update:

It was the crank pulley. Total cost to repair £195 including parts, labour & VAT.

Thanks to everyone for the info - saved some time as they could order the part first thing.

 

[Ian B Walker]

Update:

It was the crank pulley. Total cost to repair £195 including parts, labour & VAT.

Me thinks they are having a laugh.

 

[Dieselman]

Me thinks they are having a laugh.

Why is that? The pulley is probably £130 or so.

 

[Ian B Walker]

Why is that? The pulley is probably £130 or so.

£86 from Mb £53 from local motor factor. An hours work at the most too

 

[C43AMG]

This was posted a couple of years ago, never found out if it was worlwide.

www.whnet.com/4x4/pix/SC2005020003.pdf

 

[996jimbo]

£86 from Mb £53 from local motor factor. An hours work at the most too

Pulley £49.26 Labour £115, both plus VAT.

They had to remove the radiator so the labour represents (I guess) 2.5 hours work.

 

[Ade B]

Hi there

There is an interesting noise that has started on my 51k 1991 300CE 24V from the pulley area... a kind of light squeak/ tick can be heard at tickover shortly after start up.

The noise goes away when the engine revs.. it can't be heard at all from inside the car.

Doesn't appear to be the belt tensioner damper (prodded it whilst the engine was ticking over and has no discernable movement) and seems to be coming from the PAS pump side.

Everything is really jammed in there so its very difficult to inspect... but the PAS pump pulley has a few mm of play along the axis of the pulley shaft (ie it moves a bit front to back but is tight in any other direction). The belt is on pretty tight, there is no discernable slack (should there be?)

Any advice on how I can find the source of the noise for sure - spoke with local recommended specialist and they want £60 to diagnose the problem...

Is there a trick to getting at the bits without taking out the rad? I have the Haynes manual but its not great..

Advice much appreciated.

Ade

 

[Ade B]

Spoke with the weegie specialists who inspected the car before I bought it and they reckoned that the noise wasn't there when they inspected it.. of course...

they suggested that the belt was on its way out and that as a temporary stop gap I squirt the old WD40 on it - my kind of repair and lo & behold, noise went away....

and then came back

after several cycles decided to take it to local MB indy as it wasn't going away on its own..

dropped the car off this morning, at first they tell me its just a new belt, next call is to say it needs a new tensioner as the existing one is siezed...

£120 labour + parts...

Parts: tensioner, rod and damper £146.48 and belt £30

Ouch

Ade