2009 E220 CDi S211 - Vibration in D & R at idle (Eng & Trans Mounts done)

[Mintymoo]

I know vibration threads have been done to death and all fingers normally point at engine or trans mount but this doesn't fit the usual criteria so looking for any out of the box thoughts or suggestions (hate that phrase but it's applicable here).

2009 S211 OM646 220 cdi 5spd Auto with currently about 129k on the clock. Great history pre and post sale to me in 2021.

So Transmission oil & filter change done at Merc indy in late 2021 because I had just purchased the car and it hadn't been done yet, then new Lemforder engine and transmission mounts fitted in July 2022 as the car was at 125k on originals and the merc specialist health check had mentioned they were worn. All mounts changed and didn't notice any real difference to be honest but at least they were ticked off the to do list.

By September 2022 I was noticing excessive vibration of the interior plastics and a noise like you would get if an exhaust wasn't fitted properly and vibrating against the underside of the car. Only happens while stationary if you select D or R. When stopped at traffic lights it's so annoying to me that I put it in neutral but here's the thing....this only happens in the first 30 minutes of running the car, get it nice and hot on a run and the problem totally dissappears.

Injectors all replaced (brand new) and various other fuel system components when trying to zero in on a rough idle issue last year but still this problem remains. Now here's something that maybe something or nothing...my wife mentioned it took a few cranks to fire up the other day, hooked up the code reader and it stated a historic EGR 20A3 but when I inspected the EGR last summer it was amazingly clean (non DPF car).

So is this potentially transmission, prop/bearing related or downstream effect of perhaps intake manifold/EGR shenanigans? Or none of the above?

I have been underneath and looked for unwanted contact points between exhaust and body (nada) I loosened all the exhaust fitting bolts and retightened in the hope it hadn't settled since the mounts were done (nada).

I just live with it now but sh/t like this bugs me. I like to know because prevention is better than cure and all that.

 

[Wighty]

I get how that would be annoying , nothing worse than problems you can’t pin down .
So if you restart the car after an hour or two of a run does it show no symptoms of the problem?
Have you checked the gearbox oil level , there is a dipstick tube on the 5g gearbox .
Does anyone know if gearbox Torque converter problems disappear when things are hot ?

 

[malcolm E53 AMG]

My intuition is telling me it’s the gearbox early signs of a clutch or torque converter problem, the issue for me is that transmission had it’s first service at 130k miles which is way to long a period/miles, my E350cdi has had two trans fluid changes in 80k miles

 

[Larkone]

Only happens while stationary if you select D or R.
prop/bearing related

You can delete the prop/bearing as being an issue - it would only show when moving

What @malcolm210 said.

 

[rich.g.williams]

My intuition is telling me it’s the gearbox

Yes as malcolm210 I would be thinking Torque Converter.

When you are in Drive (or Reverse) the transmission is fully engaged in 1st or 2nd gear (depending upon W/S C/S setting) so the Torque Converter has to be slipping for the car to stay still. If the Torque Converter is faulty or the Lock Up clutch inside is not properly disengaged you will get heavy vibration.

Interesting however that you don't report vibration problems during normal driving at lower speeds in higher gears. The problem likely goes away after say the 30 min because the transmission ATF is warmed up to working temperature and much less viscous thus allowing the Torque Converter Lock Up clutch to slip more readily and avoid the vibration.

This does not have to be entirely inside the Torque Converter, it could be:- 1) Seals on shafts that couple from the transmission into the Torque Converter 2) A electric TCC solenoid problem 3) A hydraulic valve problem 4) Electronic ETC problem.

The Mercedes Star system is able (as a diagnostic test) to turn off the Lock Up clutch completely temporarily for a test drive and this test might be useful (if the vibration goes away) but not necessarily conclusive.

Other possibilities less likely:-

- transmission ATF pump related, flex plate between engine and Torque Converter, Engine problem when cold having to drive the Torque Converter at idle speed.

-it is noted elsewhere that any Glycol (antifreeze) contamination in the ATF can cause these sorts of problems. Apparently in some cars Glycol has squeezed through from the radiator into the ATF fluid cooler.

Low cost remedies worth trying:-

- replace the ATF fluid a second time (not the filter), in the process check for any metal filings in the transmission sump.

In answer to your question "So is this potentially transmission, prop/bearing related" It cannot be anything behind the transmission output because the car is not moving therefore the prop shaft etc are not moving, for the same reason its unlikely to be anything inside the transmission gearing because no movement if there were movement the ETC would sense it and throw an error code.

Much more likely Torque Converter or possibly engine under load at low (idle) rpm.

What happens to the vibration if you are stationary in Drive and you rev the engine a little? Does the vibration get worse or go away?

Please let us know the eventual outcome. Good luck.

 

[Mintymoo]

Wighty, Malcolm, Larkone, & Rich Thank you so much for your comments. Apologies for the long delay in reply. I got no notifications to say there had been responses to the thread coupled with family holiday and then a dose of covid meant it's been a trying few weeks!

Wighty - I haven't pulled the transmission dip stick on the assumption the indy got the level right but will do and report back.

Malcolm - The more I've thought about it and that the problem specifically dissappears when warm makes me think along your lines too. I too was dismayed to see the gearbox had never been serviced too but this is largely thanks to the absurd ethos of many manufacturers of the time stating that it wasn't a requirement (sealed for life) and therfore only got done if the owner was savvy and had done their homework.

Larkone - Thanks, sounds logical to me. I shall forget that side things.

Rich G Williams - Thank you for that superb summary of potentials. I must admit there is a little bit of rumble when pulling through the gears which I initially discounted when thinking along the lines of it must be contact between exhaust and body, it's not hugely noticeable but it's there and soon fades as engine/trans temp increases.

I had discounted the Gycol in trans issue as I was under the impression that this only affected pre-facelift W211's with the valeo radiators, is it still a potential issue in later cars?

The star diagnostics testing on lock up clutch would certainly rule it in or out. If I throw in the towel and hand it over to an indy I'll insist that it's done.

I like the sound of trying a 2nd trans fluid change from a cost perspective as it could well work and yes indeed checking for metal in the sump would be a must, do they have a magnet in the sump on these?

I visited a garage in my Truck today and was talking to a truck tech about it and although he's not familiar with Mercedes he said it does sound like an actuator of some kind due to the fact the issue resolves when run up to temp.

I will get back to you guys when I have filled in some of the blanks above but really appreciate your input

Cheers

Chris

 

[mioba]

flexible coupling

 

[markben]

Hello Mintymoo. I'm following this thread with interest since I have the same problem - albeit with a different model.

My immaculate & well-maintained 140k mile 2004 W220 S320L cdi (OM648 inline-6 engine) has similar NVH (Noise, Vibration & Harshness) issue when starting from cold. I.e. noticeable vibration felt through the steering wheel (and even the front wings!) when stationary and in 'Park / Neutral'. Plus.. an un-Mercedes-like loud 'Droning / Rasping' discordant engine noise when pulling away at low revs - different to the gentle high-pitched rattle of the legendary ultra-smooth & quiet OM648 engine even in diesel form. My NVH issue persists when the engine is warm, albeit very slight less-so. But it still doesn't sound & feel 'right'.

Like you, I've had the engine & transmission mounts replaced with Mercedes main dealer supplied OE 'Boge' parts, but with no improvement. Also, my local Indie has replaced the turbo intercooler / exhaust bracket which they say is 'the usual NVH culprit': but again, with zero improvement. Grrr...

Further down the Drivetrain, I've had the prop-shaft UV joints checked for wear (negligible), rear subframe bushes replaced, transmission ATF renewed + conductor plate. In the meantime, my 5G auto transmission changes as smooth as silk, with no nasty jolts or vibration from the prop-shaft or beyond. But... That (front / engine originated?) NVH issue persists regardless! And.. No fault codes on SDS for any related issues (e.g. cylinder shut-off valves / injector problems etc).

If it helps..? All I can suggest is that, like me, you might (stress might..) have a currently un-diagnosed issue with a worn / loose / leaking inlet or exhaust manifold & gasket: and / or a loose / rattling heat shield or air filter box which is causing that irritating NVH issue? Or... (just a long-shot..) a worn / faulty Crankshaft Harmonic Balancer pulley - which can also be a source of excessive engine NVH.

I'm not criticising Mercedes main dealers or Indies for their usually good service. That said, and from experience: they don't always have the time and / or interest in digging deep-enough into what they consider to be minor / more complex issues on 'older' (!) cars, so long as a Customer's car is 'safe, reliable & roadworthy'. Enuff said?

Either way, and as they say: 'A Mercedes should be seen, not heard'.

Best wishes & looking forward to comparing notes.

Mark B. (Somerset UK)

'The Best or Nothing'

 

[rich.g.williams]

I had discounted the Gycol in trans issue as I was under the impression that this only affected pre-facelift W211's with the valeo radiators, is it still a potential issue in later cars?

Not something I know about, a lot depends on physical separation between ATF cooler and Glycol cooler,

" like the sound of trying a 2nd trans fluid change from a cost perspective as it could well work and yes indeed checking for metal in the sump would be a must, do they have a magnet in the sump on these?"

Oh magnet yes they do, sometimes older magnets (2003) not thought to be powerful enough, but for this check point also is "metal filings" that includes Aluminium flecks that could come from a percentage of transmission parts - that said ferrous chunks would be worrying.

"I visited a garage in my Truck today and was talking to a truck tech about it and although he's not familiar with Mercedes he said it does sound like an actuator of some kind due to the fact the issue resolves when run up to temp"

There are six electrical solenoids - one of which could cause your issues is the TCC solenoid if it was allowing the lock up clutch to engage at idle, an electrical wiring fault would be seen by the ETC (TCU) and throw a code. Maybe your truck tech means hydraulic valves and yes could be cause??

How about engine idle speed is it low enough? If transmission is sweet changing through all gears then its pointing back to the Torque Converter (TCC) binding and its in a good place to make a fair amount of heavy noise (inside the bell housing). When you are getting vibration do the engine rpm drop a little? what I'm asking is the engine putting power into the wheels? Are you needing to hold the footbrake a little extra hard? If yes then again Torque Converter is coupling too much power at idle rpm.

Worth remembering is that once you select Drive the transmission is quickly locked into 1st (or 2nd gear) so transmission input shaft cannot turn unless car moves forward. So as soon as Drive selected the TCC must slip, if it does not slip engine must (and does) stall, if the TCC Lock Up clutch is (by chance because of fault) engaged - engine must and will stall.

Then there is the engine itself - engines can make plenty vibration at idle rpm if something is not right with the engine.

Have you considered something totally different causing the vibration such as something that's driven by the serpentine belt? For example the Power Steering pump, Alternator or AC Compressor?

 

[rich.g.williams]

flexible coupling

do you mean the flex plate? or the rubber couplings either end of propshaft? the rubber couplings cannot be reason for fault as described because propshaft is not turning when "stopped at lights"

 

[Mintymoo]

Not something I know about, a lot depends on physical separation between ATF cooler and Glycol cooler,

" like the sound of trying a 2nd trans fluid change from a cost perspective as it could well work and yes indeed checking for metal in the sump would be a must, do they have a magnet in the sump on these?"

Oh magnet yes they do, sometimes older magnets (2003) not thought to be powerful enough, but for this check point also is "metal filings" that includes Aluminium flecks that could come from a percentage of transmission parts - that said ferrous chunks would be worrying.

"I visited a garage in my Truck today and was talking to a truck tech about it and although he's not familiar with Mercedes he said it does sound like an actuator of some kind due to the fact the issue resolves when run up to temp"

There are six electrical solenoids - one of which could cause your issues is the TCC solenoid if it was allowing the lock up clutch to engage at idle, an electrical wiring fault would be seen by the ETC (TCU) and throw a code. Maybe your truck tech means hydraulic valves and yes could be cause??

How about engine idle speed is it low enough? If transmission is sweet changing through all gears then its pointing back to the Torque Converter (TCC) binding and its in a good place to make a fair amount of heavy noise (inside the bell housing). When you are getting vibration do the engine rpm drop a little? what I'm asking is the engine putting power into the wheels? Are you needing to hold the footbrake a little extra hard? If yes then again Torque Converter is coupling too much power at idle rpm.

Worth remembering is that once you select Drive the transmission is quickly locked into 1st (or 2nd gear) so transmission input shaft cannot turn unless car moves forward. So as soon as Drive selected the TCC must slip, if it does not slip engine must (and does) stall, if the TCC Lock Up clutch is (by chance because of fault) engaged - engine must and will stall.

Then there is the engine itself - engines can make plenty vibration at idle rpm if something is not right with the engine.

Have you considered something totally different causing the vibration such as something that's driven by the serpentine belt? For example the Power Steering pump, Alternator or AC Compressor?

Hi Rich, I went out to the car this morning to test trans oil level and quickly realised I need go buy one of those aftermarket transmission dip sticks so will do that at some point.

The car is my wife's daily runabout so I go entire weeks without driving it but this morning I started it and put it into drive and noticed a fair jolt and thud as it goes from N to D. I have just spent 20 minutes reading your incredible and very brave journey with this type of gearbox and I am seriously impressed at your thorough approach and understanding of the engineering.

Also, the revs do drop only a small amount but it does almost sound and feel like it's approaching the point of stall.

Also much of the fuel system replaced including 4 brand new delphi injectors in last 6 months so pretty sure its not a fueling issue or injector blow by. I have an icarsoft MB v2 and regularly check for codes and nothing stored of note.

I figured that adding this rough shift (when cold) symptoms might add valuable info.

Cheers

Chris

 

[00slk]

My s211 had the harsh shifts when cold, the thumps into drive and reverse. I replaced the transmission and TC from a parts car and have fixed that problem.
It was the TC locking up, it worked superbly when the car reached normal temperature. Once the TC's start this strange phenomenon it tends to spread fine shavings and scurf through the transmission. I killed a good replacement transmission by only changing the gearbox, thinking it was the problem.
Hope you get it sorted.

 

[rich.g.williams]

Hi Rich, I went out to the car this morning to test trans oil level and quickly realised I need go buy one of those aftermarket transmission dip sticks so will do that at some point.

The car is my wife's daily runabout so I go entire weeks without driving it but this morning I started it and put it into drive and noticed a fair jolt and thud as it goes from N to D. I have just spent 20 minutes reading your incredible and very brave journey with this type of gearbox and I am seriously impressed at your thorough approach and understanding of the engineering.

Also, the revs do drop only a small amount but it does almost sound and feel like it's approaching the point of stall.

Also much of the fuel system replaced including 4 brand new delphi injectors in last 6 months so pretty sure its not a fueling issue or injector blow by. I have an icarsoft MB v2 and regularly check for codes and nothing stored of note.

I figured that adding this rough shift (when cold) symptoms might add valuable info.

Cheers

Chris

Yes it does and puts a different perspective on the problem.

Quoting my own words "Worth remembering is that once you select Drive the transmission is quickly locked into 1st (or 2nd gear) so transmission input shaft cannot turn unless car moves forward. So as soon as Drive selected the TCC must slip, if it does not slip engine must (and does) stall, if the TCC Lock Up clutching is (by chance because of fault) engaged - engine must and will stall"

Following from above even the TCC cannot cope with a very quick selection of 1st (or 2nd) gear it needs approx a second so selection of 1st 2nd from Neutral in the 722.6 is specially sequenced using hydraulic valves, B2 brake and controlled by the ETC. You will get a very rough jerky engagement if the ETC is not working properly or not working, It's the default limp home mode. It's a really heavy thud as Drive is selected, engine does not stall because the Torque Converter has absorbed it fully after about 900mSec depending on ATF viscosity (Temperature).

Can't give you a certain reason for the fault but now you are into reading for codes and replacing things such as conductor plate then maybe solenoids and possibly servicing the valve body but be prepared for trouble inside the transmission and and/or a faulty Torque Converter.

Maybe read my own thread on 722.6

Slightly nagging Transmission problem 5G-Tronic 722.6 Five Speed Automatic Transmission

Good luck to op there is indy on here who offers solenoid repair, replacement plus oil n filter change at a pretty reasonable cost. When remember who, where I may go to get my tranny oiln filter changed, now at 65 odd k miles @alexanderfoti ? Maybe

forums.mercedesclub.org.uk

The link starts in page 2 but maybe worth reading from beginning and scanning through to the end.

It might help you to get a star system (or equivalent) to turn off the Torque Converter lock up clutch, if your problems go away it's telling you something. As for what's inside the TCC maybe have a look at this thread

722.6 Torque Converter (Part Number A2112500902) - Disassembly Photos

I have been trying to fix my 722.6 5G-Tronic transmission recently. My strategy is to disassemble, inspect and test everything. I reached a point where the only thing I could not get inside to inspect (and I could not rule it out as causing my fault) was the Torque Converter. I had already...

forums.mercedesclub.org.uk

cheers rich

 

[Mintymoo]

I get how that would be annoying , nothing worse than problems you can’t pin down .
So if you restart the car after an hour or two of a run does it show no symptoms of the problem?
Have you checked the gearbox oil level , there is a dipstick tube on the 5g gearbox .
Does anyone know if gearbox Torque converter problems disappear when things are hot ?

Hello Mintymoo. I'm following this thread with interest since I have the same problem - albeit with a different model.

My immaculate & well-maintained 140k mile 2004 W220 S320L cdi (OM648 inline-6 engine) has similar NVH (Noise, Vibration & Harshness) issue when starting from cold. I.e. noticeable vibration felt through the steering wheel (and even the front wings!) when stationary and in 'Park / Neutral'. Plus.. an un-Mercedes-like loud 'Droning / Rasping' discordant engine noise when pulling away at low revs - different to the gentle high-pitched rattle of the legendary ultra-smooth & quiet OM648 engine even in diesel form. My NVH issue persists when the engine is warm, albeit very slight less-so. But it still doesn't sound & feel 'right'.

Like you, I've had the engine & transmission mounts replaced with Mercedes main dealer supplied OE 'Boge' parts, but with no improvement. Also, my local Indie has replaced the turbo intercooler / exhaust bracket which they say is 'the usual NVH culprit': but again, with zero improvement. Grrr...

Further down the Drivetrain, I've had the prop-shaft UV joints checked for wear (negligible), rear subframe bushes replaced, transmission ATF renewed + conductor plate. In the meantime, my 5G auto transmission changes as smooth as silk, with no nasty jolts or vibration from the prop-shaft or beyond. But... That (front / engine originated?) NVH issue persists regardless! And.. No fault codes on SDS for any related issues (e.g. cylinder shut-off valves / injector problems etc).

If it helps..? All I can suggest is that, like me, you might (stress might..) have a currently un-diagnosed issue with a worn / loose / leaking inlet or exhaust manifold & gasket: and / or a loose / rattling heat shield or air filter box which is causing that irritating NVH issue? Or... (just a long-shot..) a worn / faulty Crankshaft Harmonic Balancer pulley - which can also be a source of excessive engine NVH.

I'm not criticising Mercedes main dealers or Indies for their usually good service. That said, and from experience: they don't always have the time and / or interest in digging deep-enough into what they consider to be minor / more complex issues on 'older' (!) cars, so long as a Customer's car is 'safe, reliable & roadworthy'. Enuff said?

Either way, and as they say: 'A Mercedes should be seen, not heard'.

Best wishes & looking forward to comparing notes.

Mark B. (Somerset UK)

'The Best or Nothing'

Thanks for your thoughts Mark. Wow you have really been down the rabbit hole with yours and I have genuine sympathy for your situation and the frustration it causes especially when you have generously opened your wallet to solve the issue to no avail.

I have had the problem since about last September and have not gone down the road of an indy yet in the hope it was going to be something other than the trans which I could remedy myself but my gut is now saying it is the actual trans. Harmonic balancer was something I pondered on for some time but this engine isn't known for that issue and there is no noticeable wobbling of the pulley when looking down at it at idle.

I did wonder about intake and exhaust manifolds too but again it doesn't quite fit because the issue is only present when engine is cold and only when D or R is selected while stationary.

As you rightly say, it's very un-mercedes like!

Good to have you along for this bush tucker trial

 

[Mintymoo]

My s211 had the harsh shifts when cold, the thumps into drive and reverse. I replaced the transmission and TC from a parts car and have fixed that problem.
It was the TC locking up, it worked superbly when the car reached normal temperature. Once the TC's start this strange phenomenon it tends to spread fine shavings and scurf through the transmission. I killed a good replacement transmission by only changing the gearbox, thinking it was the problem.
Hope you get it sorted.

Hmm very interesting. Thanks for your input and I feel for you pal, that's a ****** hard lesson to learn

 

[markben]

Thanks for your thoughts Mark. Wow you have really been down the rabbit hole with yours and I have genuine sympathy for your situation and the frustration it causes especially when you have generously opened your wallet to solve the issue to no avail.

I have had the problem since about last September and have not gone down the road of an indy yet in the hope it was going to be something other than the trans which I could remedy myself but my gut is now saying it is the actual trans. Harmonic balancer was something I pondered on for some time but this engine isn't known for that issue and there is no noticeable wobbling of the pulley when looking down at it at idle.

I did wonder about intake and exhaust manifolds too but again it doesn't quite fit because the issue is only present when engine is cold and only when D or R is selected while stationary.

As you rightly say, it's very un-mercedes like!

Good to have you along for this bush tucker trial

Thanks too, Chris.

Well, yes: in 6+ years' ownership of my now elderly & treasured (but IMHO still 'timelessly elegant') W220 'S' Class, I'm still (!) trying to resolve a similarly irritating NVH issue to yours - plus a 'mystery' Airmatic / ADS glitch which keeps the suspension in 'Hard' mode as opposed to the 'Magic Carpet' Ride despite much money spent on new OE parts and, despite which, various Mercedes Indies have failed to resolve it. But Hey ho.... I see it as 'work in progress' / a project more than a reason to lose sleep.

In the meantime, and on reflection: my nearly 19 year-old now 140k mile 'S' as been remarkably reliable & economical (for such an electronically complex, powerful & heavy car) and has never let me-down apart from a relatively minor battery-drain issue which was quickly resolved by an expert local auto electrician. Phew...!

I guess the bottom-line on these types of 'mystery' faults is: if our Mercedes cars (or any car for that matter?) start, drive, stop & perform reliably and safely, that's the main thing? And especially for us or those of our N&D (like your wife?) who use them as Daily Drivers.

In my long & varied Life's experience (Ha ha!) I've learned that, sometimes, adopting a 'Good Enough' attitude (within reason & in context..) can be easier on the Mind than seeking Perfection at all costs - Food for Thought..? . That said: I can understand and relate to your desire to get your NVH issue fixed .

Either way, looking forward to comparing notes - and with tons of expert technical help & advice from others on this friendly & helpful forum.

MB

 

[rich.g.williams]

Hello Mintymoo. I'm following this thread with interest since I have the same problem - albeit with a different model.

My immaculate & well-maintained 140k mile 2004 W220 S320L cdi (OM648 inline-6 engine) has similar NVH (Noise, Vibration & Harshness) issue when starting from cold. I.e. noticeable vibration felt through the steering wheel (and even the front wings!) when stationary and in 'Park / Neutral'. Plus.. an un-Mercedes-like loud 'Droning / Rasping' discordant engine noise when pulling away at low revs - different to the gentle high-pitched rattle of the legendary ultra-smooth & quiet OM648 engine even in diesel form. My NVH issue persists when the engine is warm, albeit very slight less-so. But it still doesn't sound & feel 'right'.

Like you, I've had the engine & transmission mounts replaced with Mercedes main dealer supplied OE 'Boge' parts, but with no improvement. Also, my local Indie has replaced the turbo intercooler / exhaust bracket which they say is 'the usual NVH culprit': but again, with zero improvement. Grrr...

Further down the Drivetrain, I've had the prop-shaft UV joints checked for wear (negligible), rear subframe bushes replaced, transmission ATF renewed + conductor plate. In the meantime, my 5G auto transmission changes as smooth as silk, with no nasty jolts or vibration from the prop-shaft or beyond. But... That (front / engine originated?) NVH issue persists regardless! And.. No fault codes on SDS for any related issues (e.g. cylinder shut-off valves / injector problems etc).

If it helps..? All I can suggest is that, like me, you might (stress might..) have a currently un-diagnosed issue with a worn / loose / leaking inlet or exhaust manifold & gasket: and / or a loose / rattling heat shield or air filter box which is causing that irritating NVH issue? Or... (just a long-shot..) a worn / faulty Crankshaft Harmonic Balancer pulley - which can also be a source of excessive engine NVH.

I'm not criticising Mercedes main dealers or Indies for their usually good service. That said, and from experience: they don't always have the time and / or interest in digging deep-enough into what they consider to be minor / more complex issues on 'older' (!) cars, so long as a Customer's car is 'safe, reliable & roadworthy'. Enuff said?

Either way, and as they say: 'A Mercedes should be seen, not heard'.

Best wishes & looking forward to comparing notes.

Mark B. (Somerset UK)

'The Best or Nothing'

Hello Mark,

So a six cylinder 648.960 vibrating starting from cold.

Yes absolute certainty needed that all manifold seals turbo, intercooler etc all sealed and absolutely no cracks. Entire exhaust 100% no cracks no rattling guard plates. Glow plugs all working the same any imbalance in cold weather would create vibration, all injectors tested working 100% no injector leaks of seal to cylinder head. Fuel supply to the common rail is good and common rail pressure is normal.

Noisy startup is a diesel engine thing, too cold in the cylinder at first irregular firing noise vibration. Cylinder head porosity problems or even a tiny gasket leak could cause problems

Then you have possible valve problems, chain wear chain guide wear.

Then there is everything attached to the serpentine belt, suggest try removing the serpentine belt, starting and running engine for a short time without the serpentine belt (not too long because water pump not pumping and Alternator not charging) long enough to decide if any noise vibration has has not wonderfully gone away.

Then is the engine getting enough air are you sure no soot in the intake, often worth removing everything and cleaning out the inlet and exhaust manifolds etc and any EGR equipment around and about, I have seen unbelievable amounts of soot in diesel engine air supply, severe shortage of air will be imbalanced cylinder to cylinder and will cause vibration at low rpm .

Also fault codes , a detailed analysis and search for fault codes from the engine ECU might shed some light as would study of the real time ECU parameters via the Star diagnostic system.

Lastly a very thorough inspection of the exhaust system mountings clearances etc, even a slightly mis-positioned exhaust can sound bad.

It's worth thinking carefully about the symptoms, for instance does the engine create noise (at low road speeds) when trying to accelerate or when foot off decelerating, if the latter simply the Alternator can do this.

 

[markben]

Hello Mark,

So a six cylinder 648.960 vibrating starting from cold.

Yes absolute certainty needed that all manifold seals turbo, intercooler etc all sealed and absolutely no cracks. Entire exhaust 100% no cracks no rattling guard plates. Glow plugs all working the same any imbalance in cold weather would create vibration, all injectors tested working 100% no injector leaks of seal to cylinder head. Fuel supply to the common rail is good and common rail pressure is normal.

Noisy startup is a diesel engine thing, too cold in the cylinder at first irregular firing noise vibration. Cylinder head porosity problems or even a tiny gasket leak could cause problems

Then you have possible valve problems, chain wear chain guide wear.

Then there is everything attached to the serpentine belt, suggest try removing the serpentine belt, starting and running engine for a short time without the serpentine belt (not too long because water pump not pumping and Alternator not charging) long enough to decide if any noise vibration has has not wonderfully gone away.

Then is the engine getting enough air are you sure no soot in the intake, often worth removing everything and cleaning out the inlet and exhaust manifolds etc and any EGR equipment around and about, I have seen unbelievable amounts of soot in diesel engine air supply, severe shortage of air will be imbalanced cylinder to cylinder and will cause vibration at low rpm .

Also fault codes , a detailed analysis and search for fault codes from the engine ECU might shed some light as would study of the real time ECU parameters via the Star diagnostic system.

Lastly a very thorough inspection of the exhaust system mountings clearances etc, even a slightly mis-positioned exhaust can sound bad.

It's worth thinking carefully about the symptoms, for instan appreciate yoiur thoughtce does the engine create noise (at low road speeds) when trying to accelerate or when foot off decelerating, if the latter simply the Alternator can do this.

Thanks Rich!

Yes, that NVH & irritating 'rasping / blowing / droning' noise is mainly at low speeds when starting the engine & driving from cold, the worst symptoms, and only slightly milder when warmed-up. The engine & transmission feel perfect otherwise (no engine mis-fires, ultra smooth transmission changes etc).

Like you suggest, my money's on a (possible slight) inlet / exhaust manifold gasket leak... OR some even slight metal-to-metal contact between the engine and / or exhaust system and the bodywork. But I get your thoughts about the other possible causes - that makes sense too.

Either way, I appreciate your thoughts / suggestions & will keep you up-dated on progress.

Back soon with more.. thanks again

MB

 

[rich.g.williams]

Chris,

Have been scanning through your thread again, just a few quick comments.

See that you have noticed some possible TCC noise through the gears. Maybe worth having a read about so called "rumble strip noise (RSN)" There is no end of chatter about it on the net - here is just one thread :-

RSN

Think your low cost options are to have a look at the ATF inside the transmission sump and maybe get the valve body out (messy but doable) give it and the conductor plate a good clean. There are some small filters in there and metal filings can gum up the speed sensors.

If you are lucky you might just disturb/clean something that fixes things.

If that does not improve things, then more work on the TCC/transmission maybe on the cards.

 

[tavernole]

Thanks too, Chris.

Well, yes: in 6+ years' ownership of my now elderly & treasured (but IMHO still 'timelessly elegant') W220 'S' Class, I'm still (!) trying to resolve a similarly irritating NVH issue to yours - plus a 'mystery' Airmatic / ADS glitch which keeps the suspension in 'Hard' mode as opposed to the 'Magic Carpet' Ride despite much money spent on new OE parts and, despite which, various Mercedes Indies have failed to resolve it. But Hey ho.... I see it as 'work in progress' / a project more than a reason to lose sleep.

In the meantime, and on reflection: my nearly 19 year-old now 140k mile 'S' as been remarkably reliable & economical (for such an electronically complex, powerful & heavy car) and has never let me-down apart from a relatively minor battery-drain issue which was quickly resolved by an expert local auto electrician. Phew...!

I guess the bottom-line on these types of 'mystery' faults is: if our Mercedes cars (or any car for that matter?) start, drive, stop & perform reliably and safely, that's the main thing? And especially for us or those of our N&D (like your wife?) who use them as Daily Drivers.

In my long & varied Life's experience (Ha ha!) I've learned that, sometimes, adopting a 'Good Enough' attitude (within reason & in context..) can be easier on the Mind than seeking Perfection at all costs - Food for Thought..? . That said: I can understand and relate to your desire to get your NVH issue fixed .

Either way, looking forward to comparing notes - and with tons of expert technical help & advice from others on this friendly & helpful forum.

MB

Hi markben, a good tip someone mentioned to fix the hard suspension issue was to unplug the electrical contacts near the top of the suspension on both side and spray with electrical contact cleaner, it solved the problem I had with hard suspension