Vibrations after replacing engine mounts
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W212 E550 4matic M273
Vibrations after replacing engine mounts
Hey guys! I am having the following issue - I have had strong vibrations in the steering wheel and seat so I decided to go for new engine and gearbox mounts. I have been advised from my mechanic to put only OEM parts because the after market parts are trash and the replacement on the 4matic models is pain in the bum, especially being the W212 with V8 engine. After the replacement itself the car was performing like an electric vehicle while at full stop at a traffic light, you couldn't understand that it's actually working (maintaining 600 rpm on second gear with absolutely no vibrations). However, in 3 weeks, again vibrations started to show. I am excluding the possibility for the OEM parts to go bad for like 3 weeks after install. I have paid 1000 EUR or 1100 USD for this service with the labour. I went back to my mechanic and he said that the vibrations that it has are quite normal, other guy told me that on the 4matic models, there are always vibrations. But why then they disappeared totally after the replacement? I am very confused.
Another strange thing was that couple of days ago it went to 0 vibrations as well but it was only for the day, now it has like 20% vibrations again.
Vibrations before - 100%
Vibrations after - 0%
Vibrations now - 20%
Another strange thing was that couple of days ago it went to 0 vibrations as well but it was only for the day, now it has like 20% vibrations again.
Vibrations before - 100%
Vibrations after - 0%
Vibrations now - 20%
Last edited by adicolor212; Apr 7, 2025 at 07:44 AM.
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From: Fleriduh
W212 E63S Wagon - GSL580 - E63 - E350 - C300
Been in your shoes. The OE mounts are fluid filled. I have heard (second hand from my mechanic) that there have been instances of bad from the factory (NOS issues) or the fluid area gets damaged if someone trys to pound in the new mount in the tight area. I am not certain if you can see the fluid leaking out -
Oh, did you change the trans mount as well?
Oh, did you change the trans mount as well?
Last edited by OldManAndHisCar; Apr 7, 2025 at 08:36 AM.
Thread Starter
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W212 E550 4matic M273
The mechanic that installed them is a professional and he knows all about them. Changed tranny mount yes. 2 engine mounts + trans mount OEM bought directly from MB. Is it possible to be rougher because of the cold weather ?
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
There is also the traditional way to test the engine mounts. Put the car in reverse, stand on the brake, give a little gas, and see if the engine rocks a lot (hood open). Make sure no one is behind you!
Last edited by JettaRed; Apr 7, 2025 at 04:34 PM.
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Since they are fluid filled, then yes, temperature can affect the stiffness. Was there significant temperature differences between now and right after replacement.
There is also the traditional way to test the engine mounts. Put the car in reverse, stand on the brake, give a little gas, and see if the engine rocks a lot (hood open). Make sure no one is behind you!
There is also the traditional way to test the engine mounts. Put the car in reverse, stand on the brake, give a little gas, and see if the engine rocks a lot (hood open). Make sure no one is behind you!
Out Of Control!!
Joined: Apr 2019
Posts: 12,172
Likes: 6,883
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
STANDARD UNEVEN CONTRIBUTIONS
Hey guys! I am having the following issue - I have had strong vibrations in the steering wheel and seat so I decided to go for new engine and gearbox mounts. I have been advised from my mechanic to put only OEM parts because the after market parts are trash and the replacement on the 4matic models is pain in the bum, especially being the W212 with V8 engine. After the replacement itself the car was performing like an electric vehicle while at full stop at a traffic light, you couldn't understand that it's actually working (maintaining 600 rpm on second gear with absolutely no vibrations). However, in 3 weeks, again vibrations started to show. I am excluding the possibility for the OEM parts to go bad for like 3 weeks after install. I have paid 1000 EUR or 1100 USD for this service with the labour. I went back to my mechanic and he said that the vibrations that it has are quite normal, other guy told me that on the 4matic models, there are always vibrations. But why then they disappeared totally after the replacement? I am very confused.
Another strange thing was that couple of days ago it went to 0 vibrations as well but it was only for the day, now it has like 20% vibrations again.
Vibrations before - 100%
Vibrations after - 0%
Vibrations now - 20%
Another strange thing was that couple of days ago it went to 0 vibrations as well but it was only for the day, now it has like 20% vibrations again.
Vibrations before - 100%
Vibrations after - 0%
Vibrations now - 20%
Engine vibrations are the marker sign of
This is a call for (ignition) service and to not stressing high output from few cylinders.
Your engine condition is the factory preferred course for aging vehicle... as this condition progress you will get "misfirings" CEL faults.
> Let Me Ask For Your Inputs :
-A- How old are the ignition parts?
(spark plugs + boots /coils)
-B- What oil is in use ?
(standard 0W-40 for 10,000.Mi )
-C- How old are the loose chain tensioners ??
(originals)
-D- How much oil does the engine consumes ?
(over 1Qt?)
-E- How old are the exhaust Lambda sensors ??
(dirty originals)
-F- How lean are your engine fuel trims ??
(lean LTFT-9)
Refrain from "Italian tune-up" (high Rpm) your engine is running unevenly on few cylinders.
It needs service by your local MB specialist.
Last edited by CaliBenzDriver; Apr 7, 2025 at 06:22 PM.
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From: MA Coast
W204 2010 C300 4matic Sport M272
Just throwing this out there, have you inspected the exhaust? May have a loose connection/clamp, or worn hanger. I had to replace all my exhaust clamps because they were all rusted.
Few months ago I was feeling a slight vibration at red lights where I was thinking it may be engine or trans mounts. I happen to have a bottle of Techron so used it in the gas tank, within a few days I forgot all about the vibrations.
Few months ago I was feeling a slight vibration at red lights where I was thinking it may be engine or trans mounts. I happen to have a bottle of Techron so used it in the gas tank, within a few days I forgot all about the vibrations.
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Just throwing this out there, have you inspected the exhaust? May have a loose connection/clamp, or worn hanger. I had to replace all my exhaust clamps because they were all rusted.
Few months ago I was feeling a slight vibration at red lights where I was thinking it may be engine or trans mounts. I happen to have a bottle of Techron so used it in the gas tank, within a few days I forgot all about the vibrations.
Few months ago I was feeling a slight vibration at red lights where I was thinking it may be engine or trans mounts. I happen to have a bottle of Techron so used it in the gas tank, within a few days I forgot all about the vibrations.
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Joined: May 2018
Posts: 6,647
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From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
How many miles is the car and how old ?
Engine>>.Tranny>>>Driveline>>>if 4matic two drive lines front and back.
Isolate your vibration : is it from driveline or engine ?
In neutral/park, rev engine slowly to max allowed RPM ( engine must be warm ) , see if vibration exist ?
If while car is moving, what RPM and what speed and what gear was it vibrating worst ?
Engine>>.Tranny>>>Driveline>>>if 4matic two drive lines front and back.
Isolate your vibration : is it from driveline or engine ?
In neutral/park, rev engine slowly to max allowed RPM ( engine must be warm ) , see if vibration exist ?
If while car is moving, what RPM and what speed and what gear was it vibrating worst ?
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 26
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W212 E550 4matic M273
Does this vibration coming and going help you realize your engine is the cause, not the new mounts ??
Engine vibrations are the marker sign ofpoor unsettled combustion timings... literally crank acceleration/deceleration on each contribution.
This is a call for (ignition) service and to not stressing high output from few cylinders.
Your engine condition is the factory preferred course for aging vehicle... as this condition progress you will get "misfirings" CEL faults.
> Let Me Ask For Your Inputs :
-A- How old are the ignition parts?
(spark plugs + boots /coils)
-B- What oil is in use ?
(standard 0W-40 for 10,000.Mi )
-C- How old are the loose chain tensioners ??
(originals)
-D- How much oil does the engine consumes ?
(over 1Qt?)
-E- How old are the exhaust Lambda sensors ??
(dirty originals)
-F- How lean are your engine fuel trims ??
(lean LTFT-9)
Refrain from "Italian tune-up" (high Rpm) your engine is running unevenly on few cylinders.
It needs service by your local MB specialist.
Engine vibrations are the marker sign of
This is a call for (ignition) service and to not stressing high output from few cylinders.
Your engine condition is the factory preferred course for aging vehicle... as this condition progress you will get "misfirings" CEL faults.
> Let Me Ask For Your Inputs :
-A- How old are the ignition parts?
(spark plugs + boots /coils)
-B- What oil is in use ?
(standard 0W-40 for 10,000.Mi )
-C- How old are the loose chain tensioners ??
(originals)
-D- How much oil does the engine consumes ?
(over 1Qt?)
-E- How old are the exhaust Lambda sensors ??
(dirty originals)
-F- How lean are your engine fuel trims ??
(lean LTFT-9)
Refrain from "Italian tune-up" (high Rpm) your engine is running unevenly on few cylinders.
It needs service by your local MB specialist.
Car is read with Xentry original mercedes diagnostics - no faults, no codes, nothing.
Spark plugs are like 10k miles
Oil is changed every 6k miles (5-40 liqui moly 229.5)
Engine consumes about 500 ml per 6k miles
Coils are original.
Fuel trims are normal, however, when I was replacing the old air filters from the previous owner, the guy put literally the cheapest thing on the market, so I have bought TB cleaner + MAF cleaner but I haven't clean them yet because the car is at Mercedes Benz for replacing rear subframe (you know that they rot).
BTW! The rear subframe was cracked, might this cause vibrations while at full stop but on D gear ?
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 26
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W212 E550 4matic M273
How many miles is the car and how old ?
Engine>>.Tranny>>>Driveline>>>if 4matic two drive lines front and back.
Isolate your vibration : is it from driveline or engine ?
In neutral/park, rev engine slowly to max allowed RPM ( engine must be warm ) , see if vibration exist ?
If while car is moving, what RPM and what speed and what gear was it vibrating worst ?
Engine>>.Tranny>>>Driveline>>>if 4matic two drive lines front and back.
Isolate your vibration : is it from driveline or engine ?
In neutral/park, rev engine slowly to max allowed RPM ( engine must be warm ) , see if vibration exist ?
If while car is moving, what RPM and what speed and what gear was it vibrating worst ?
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 26
Likes: 0
W212 E550 4matic M273
Just throwing this out there, have you inspected the exhaust? May have a loose connection/clamp, or worn hanger. I had to replace all my exhaust clamps because they were all rusted.
Few months ago I was feeling a slight vibration at red lights where I was thinking it may be engine or trans mounts. I happen to have a bottle of Techron so used it in the gas tank, within a few days I forgot all about the vibrations.
Few months ago I was feeling a slight vibration at red lights where I was thinking it may be engine or trans mounts. I happen to have a bottle of Techron so used it in the gas tank, within a few days I forgot all about the vibrations.
I am running LPG system so the car doesn't work on gasoline that often, but when it does, it makes no difference. You cannot differentiate between running on LPG or gas.
Out Of Control!!
Joined: Apr 2019
Posts: 12,172
Likes: 6,883
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
LTFT ?
Hey hey! thank you for the exhaustive answer.
Car is read with Xentry original mercedes diagnostics - no faults, no codes, nothing.
Spark plugs are like 10k miles
Oil is changed every 6k miles (5-40 liqui moly 229.5)
Engine consumes about 500 ml per 6k miles
Coils are original.
Fuel trims are normal, however, when I was replacing the old air filters from the previous owner, the guy put literally the cheapest thing on the market, so I have bought TB cleaner + MAF cleaner but I haven't clean them yet because the car is at Mercedes Benz for replacing rear subframe (you know that they rot).
BTW! The rear subframe was cracked, might this cause vibrations while at full stop but on D gear ?
Car is read with Xentry original mercedes diagnostics - no faults, no codes, nothing.
Spark plugs are like 10k miles
Oil is changed every 6k miles (5-40 liqui moly 229.5)
Engine consumes about 500 ml per 6k miles
Coils are original.
Fuel trims are normal, however, when I was replacing the old air filters from the previous owner, the guy put literally the cheapest thing on the market, so I have bought TB cleaner + MAF cleaner but I haven't clean them yet because the car is at Mercedes Benz for replacing rear subframe (you know that they rot).
BTW! The rear subframe was cracked, might this cause vibrations while at full stop but on D gear ?
No obvious cause stands out.
What value are each banks LongTerm Fuel-Trims at idle?
This will tell you how efficiently combustions are running. The vibrations you're sensing are from lean misfires regardless of 10k new sparkplugs only ignition (no codes).
Thread Starter
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W212 E550 4matic M273
Yesterday I did some testing (I am QA Engineer by profession so.. 
) When I drive the car and I stop and I am still in gear and holding the brake, there are vibrations, however, if I put it on P and then back to D - no vibrations
) When I drive the car and I stop and I am still in gear and holding the brake, there are vibrations, however, if I put it on P and then back to D - no vibrations
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From: Chicago
19 GLA45, 86 560SL, former: 14 E550 4Matic, 09 E350 4Matic, 83 240D manual, 78 450SLC, 81 500SLC
Longshot here, but I had similar problems when I replaced the transmission mount on my 240D a long time ago. It was solved by loosening the mount and letting the transmission's weight rest fully on the mount and then re-tightening it.
Sometimes if a mount isn't tightened in the right position, it can transmit vibrations in one situation or another...
Sometimes if a mount isn't tightened in the right position, it can transmit vibrations in one situation or another...
