Engine & Gearbox mounts changed today - is this normal?

[such]

Had all 3 mounts changed today - febi bilstein engine mounts and lemforder gearbox.
The original MB mounts were worn with the rubber screw insert part collapsing into the body of the mount on both sides, and the gearbox mount worn.
The reason for change was preventative maintenance - I did not notice any undue vibrations, except a slight steering vibration at motorway speeds.
I was surprised when seeing how bad the old mounts were that I had not noticed anything to indicate they were that knackered.

On the 40 mile drive back the car felt smooth and quiet, noticeably better than before, on fast roads.
After a few hours standing, when getting back in the car and moving off, the gearbox sounds much louder and I can feel vibrations from the bottom of the car and also through the accelerator.
The car does not feel smooth at all at low speeds and when slowing down feels like it's going to stall. It feels like there is a constant vibration going through the cabin, which was not present before - in fact a colleague recently mentioned how smooth the drive was.
Is it possible the mounts may be defective?

 

[sonic]

In 56 years of driving I have never changed an engine mount, & I have had 6 MB's which are normally kept to over 100K miles.
I have a 212 E350CDI 2011 version, how many miles is on yours?
I am just wondering if the engine mounts are masking something else?

 

[star]

I have changed plenty and seen lots of aftermarket mounts not last.

 

[such]

In 56 years of driving I have never changed an engine mount, & I have had 6 MB's which are normally kept to over 100K miles.
I have a 212 E350CDI 2011 version, how many miles is on yours?
I am just wondering if the engine mounts are masking something else?

Currently on 183k

 

[such]

I have changed plenty and seen lots of aftermarket mounts not last.

Surely they would last more than 40miles?

 

[such]

I'll see what it's like today and have a chat with the garage if still the same.

 

[s5tuart]

I wonder if the mounts need to be at the correct torque setting?

Got me worried as I'll be changing mine in a couple of weeks


ETA....my local garage man, non MB, says there's nothing wrong with the engine mounts. Result!!!

 

[such]

Well it was very rough this morning, lots of vibrations seemed to quieten down with more driving.
Booked back with specialist on Monday.

 

[rayhennig]

Had all 3 mounts changed today - febi bilstein engine mounts and lemforder gearbox.

I've seen others who've said that Febi supplies solid mounts instead of hydraulic ones. No direct experience so this is hearsay. But Febi can be a lottery in terms of quality.

RayH

 

[such]

Both mounts were hydro. Just checked my order.

 

[markben]

In 56 years of driving I have never changed an engine mount, & I have had 6 MB's which are normally kept to over 100K miles.
I have a 212 E350CDI 2011 version, how many miles is on yours?
I am just wondering if the engine mounts are masking something else?

Both mounts were hydro. Just checked my order.

If it helps...?

I have a similar engine (and / or drivetrain?) NVH issue with my otherwise immaculate & well-maintained 2004 140k mile W220 S 320 inline-6 cdi (which, especially, should be super-smooth & quiet). The Symptoms: vibration felt through steering wheel and (and front wings!) when in 'N' or 'P' at idle. Raucous, deep 'rasping' noise from engine when starting & pulling away from cold, less-so when warm - but still there. Excessive engine shudder when shutting down. Some rear drivetrain NVH at low revs in higher gears. Otherwise, it performs brilliantly with fantastic fuel economy for a W220 'Limo'

Work / investigations done by my local Indie & local garage: 1. New Mercedes supplied OE 'Boge' stamped engine & Trans mounts - but virtually NO improvement on the original 120k mile ones. Grrr... 2. Indie checked if new engine mounts have been wrongly fitted 'L' / 'R' handed due to different part numbers / possibly differing technical specs - but says they are 'ok'. Mmmm? 3. Indie has replaced various Drivetrain components including Propshaft Flexi couplings, rear (front) Subframe bushes, rear NHS suspension arm + bushings, etc etc. Plus replaced Turbo Intercooler exhaust bracket which he says is a common engine NVH problem.

Despite all this: virtually NO improvement in the various NVH symptoms. Grrr again.

After some research on other respected Mercedes technical forums, it seems that there are a myriad of issues which might (stress might..) conspire to contribute to this type of NVH problem including any or all of:

Injector faults (at high mileage ?), Cylinder combustion imbalance or shut-down valve faults, Manifold inlet & outlet gasket leaks, Worn / loose Airbox rubber mounts, EGR soot issues (again, at high mileage?), worn Crankshaft Harmonic Balancer, Ancilliary Serpentine Belt etc.

Of course, a competent & patient Mercedes Indie should (stress 'should!..') be able to join the NVH diagnostic dots with the help of SDS: but sadly, from experience, it doesn't always work that way unless a Customer's car has a seriously disabling driving / mechanical / safety fault. Enuff said?

Hope this helps in some way. I'll follow this thread with interest and update on any progress with my (similar) NVH symptoms / fixes as appropriate.

MB

'The Best or Nothing'

 

[markben]

Both mounts were hydro. Just checked my order.

I have a similar engine (and / or drivetrain?) NVH issue with my otherwise immaculate & well-maintained 2004 140k mile W220 S 320 inline-6 cdi (which, especially, should be super-smooth & quiet). The Symptoms: vibration felt through steering wheel and (and front wings!) when in 'N' or 'P' at idle. Raucous, deep 'rasping' noise from engine when starting & pulling away from cold, less-so when warm - but still there. Excessive engine shudder when shutting down. Some rear drivetrain NVH at low revs in higher gears. Otherwise, it performs brilliantly with fantastic fuel economy for a W220 'Limo'

Work / investigations done by my local Indie & local garage: 1. New Mercedes supplied OE 'Boge' stamped engine & Trans mounts - but virtually NO improvement on the original 120k mile ones. Grrr... 2. Indie checked if new engine mounts have been wrongly fitted 'L' / 'R' handed due to different part numbers / possibly differing technical specs - but says they are 'ok'. Mmmm? 3. Indie has replaced various Drivetrain components including Propshaft Flexi couplings, rear (front) Subframe bushes, rear NHS suspension arm + bushings, etc etc. Plus replaced Turbo Intercooler exhaust bracket which he says is a common engine NVH problem.

Despite all this: virtually NO improvement in the various NVH symptoms. Grrr again.

After some research on other respected Mercedes technical forums, it seems that there are a myriad of issues which might (stress might..) conspire to contribute to this type of NVH problem including any or all of:

Injector faults (at high mileage ?), Cylinder combustion imbalance or shut-down valve faults, Manifold inlet & outlet gasket leaks, Worn / loose Airbox rubber mounts, EGR soot issues (again, at high mileage?), worn Crankshaft Harmonic Balancer, Ancilliary Serpentine Belt etc.

Of course, a competent & patient Mercedes Indie should (stress 'should!..') be able to join the NVH diagnostic dots with the help of SDS: but sadly, from experience, it doesn't always work that way unless a Customer's car has a seriously disabling driving / mechanical / safety fault. Enuff said?

Hope this helps in some way. I'll follow this thread with interest and update on any progress with my (similar) NVH symptoms / fixes as appropriate.

MB

'The Best or Nothing'

 

[such]

Pardon my ignorance - what's NVH?

 

[Blobcat]

Pardon my ignorance - what's NVH?

Noise, Vibration, Harshness

 

[markben]

Pardon my ignorance - what's NVH?

No worry . The Term 'NVH' (Noise, Vibration & Harshness) is an automotive Industry / Manufacturers' term & Parameters for 'Acceptably' Quiet & Comfortable - within reason & measurable limits on New Vehicles). 'Excessive' NVH on older cars can be attributed to any or all of Engine & Transmission faults or other issues. But, of course, on older cars, 'excessive' NVH can be due to any manner of other faults for a variety of reasons including poor maintenance etc. And.. and to confuse the issue further (!).. an owner's perception of what 'excessive NVH' means has to be taken in context.

Either way, please keep us posted on your investigations and I'll be happy to share notes from my side of a similar NVH issue.

 

[such]

I hope it's something simple - I never had any NVH prior to the mounts being changed. The car has been well maintained with everything needed being done and oil changes every 8k

 

[markben]

I hope it's something simple - I never had any NVH prior to the mounts being changed. The car has been well maintained with everything needed being done and oil changes every 8k

Yes, that's the frustrating paradox! New OE engine mounts etc.. but the same (or more) NVH?! As someone else here said: maybe.. the new e/mounts (although not the principal cause) might have have highlighted or revealed a NVH issue somewhere else in either your engine or drivetrain. Again: my best suggestion is to take your car to a recommended / trusted Mercedes Indie and ask them to systematically work-through & eliminate ALL of the possible causes - with some help from SDS (the Mercedes Star Diagnostic System).

Good luck & keep us posted

 

[such]

I will do- it's going back to Alex Crow to look at on Monday, the engine is very smooth - I have noticed it doesn't feel like its jumping around when cold starting now.

 

[such]

Well the drivers side Febi engine mount lasted approx 40miles.
It collapsed with the fluid leaking out.
Replaced with MB mount and now no vibrations.
I really wasn't expecting the febi mount to cause any issues so soon.

 

[Conor]

It would be worth investigating the state of Guibo / Propshaft coupling / "donut" etc. One on each end of the propshaft.

These are rubber and prone to failure also.

I recently changed my 3 mounts out for Lemforder units. Car was on about 225k miles.

At the same time I changed my propshaft couples and they were quite worn. It's possible the NVH might be from there but the transmission was picking it up and hiding.

I've hears stories before of guys chasing NVH on high mile cars.. changing out one rubber just shows up something else.