ML 320 Cdi turbo noise

[mickeyJ]

Having recently bought an early ML320 Cdi, I,ve being sorting out various engine oil leaks which I understand are fairly common on this engine.
One of the leaks was a drip from the turbo to intercooler noise damper unit.
My local indy told me that MB don,t supply the seals separately and so a new damper was fitted. Solved the oil drip, but left me with a very annoying noise when decelerating, almost like a shot wheel bearing rumble.
Wondered if anyone else has experienced this, and is there a mod or fix for it ?

 

[kid-jensen]

If you have an early W164 (your info doesn't say), they are prone to front Diff bearing failure, due to suspect bearings from one specific factory.

If it sounds like a bearing, it might be!

 

[mickeyJ]

Hello and many thanks for your input. Yes, the noise could well be mistaken for a diff bearing or similar but the problem is apparent even when the car is stationary.
With engine running, apply some throttle 1500-2000 rpm and then release pedal - horrible rumbling noise that stops when back at idle.
According to the main stealers who supplied the part, this is apparently normal - some do make a noise,and some don,t but there surely must be a reason as the original leaky unit didn,t make this noise at all

 

[kid-jensen]

I guess the question you need to ask the stealer is: "how can you prove to me that the noise damper is not faulty?.....it's making a noise, so obviously not doing it's job"

 

[mickeyJ]

Easier said than done I,m afraid, our local stealer has a serious dose of " not effing interested " - the part was fitted to cure an oil leak which it has, so I can,t really argue that point.
Issue is further compounded by the indy,s confirmation that this noise is not unusual.

 

[mickeyJ]

If you have an early W164 (your info doesn't say), they are prone to front Diff bearing failure, due to suspect bearings from one specific factory.

If it sounds like a bearing, it might be!

Looks like you are probably quite correct with your diagnosis. Replaced the front hub bearings but the noise persisted
I finally got round to draining the front diff oil for a look see and not a pretty sight !
Full of white metal particles, so I expect the inner carrier bearings must be breaking up.
Suppose it,s time for a front diff overhaul.
Having a brief look at the setup, it looks like a fairly straighforward job to drop the diff.
Does anyone know if the front hubs have to be dismantled or can they be eased back with the upper lower ball joints and track rods disconnected in order to release the driveshafts ?