Engine Mount Replacement
Junior Member
Joined: Apr 2014
Posts: 20
Likes: 0
05 C230, 15 C300
Amazing difference
I recently changed the two engine mounts and the transmission mount on my 2005 C230. The difference is amazing. I bought the car used and now I can only imagine that this is what it felt like when it was new. Like everyone said the transmission and passenger's side mount was easy to replace. However the driver's side was challenging. There is limited space to reach the top bolt on the driver's side. I tried with a short wrench but I could not loosen it. I finally gave up and bought the Assenmacher M1620 tool. It made the job a lot easier. I used Lemforder mounts. The right and left had the same part number but the cover is not used on the driver's side.
MBWorld Fanatic!
Joined: Oct 2004
Posts: 1,305
Likes: 37
From: Las Vegas, Nevada
2013 C350 Coupe, 2005 C230K Kleemann Sedan, 2013 GLK350 4matic
boom132, WIS says "remove the compressor". I have a feeling that it's not an option for you 
Someone has replaced the driver's side mount himself, but didn't give any specific comments, except that "it was hard to get to the upper bolt" or smth. I thought with a 'flat' wrench you could get to it?
Someone has replaced the driver's side mount himself, but didn't give any specific comments, except that "it was hard to get to the upper bolt" or smth. I thought with a 'flat' wrench you could get to it?
Super Member
Joined: Mar 2012
Posts: 968
Likes: 62
From: San Francisco, CA
2005 c230SS
This unfortunately sucks. I already paid over $1000 to the dealership to replace one faulty tensioner several years back, and now mine is starting to warble again if I turn on the AC when I first start the engine. Fortunately I think it's about time to replace the supercharger as well (maybe the AC compressor too for good measure.)
MBWorld Fanatic!
Joined: May 2017
Posts: 2,290
Likes: 434
C320
I just did the mounts on my 02 C320 last week. I ordered Lemforder mounts for an E320 because they were $25 a side cheaper than the C320 mounts. As far as I can tell the only difference is that the C320 mounts come with a silicone cover to protect them from grease and heat, and the E320 mounts don't I just reused the old covers.
Driver's side was easy, just pull the alternator, passenger side I had to replace the seized AC compressor so good time to do the mounts.
Despite looking different, the E320 mounts popped right in and now the car as smooth as **** from a duck's ***.
Driver's side was easy, just pull the alternator, passenger side I had to replace the seized AC compressor so good time to do the mounts.
Despite looking different, the E320 mounts popped right in and now the car as smooth as **** from a duck's ***.
MBWorld Fanatic!
Joined: Jun 2002
Posts: 7,268
Likes: 172
From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Great info. I'm quite certain mine are gone. Ah, finally pass smog..wonder how long till something else?
Not long... but hey, 245K still runs great, and no payments. Look forward to completing this job.
Not long... but hey, 245K still runs great, and no payments. Look forward to completing this job.
MBWorld Fanatic!
Joined: Jun 2002
Posts: 7,268
Likes: 172
From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Holy Crap! $ A grand for a tensioner? I recently replaced one of mine (m111 has 2)
for the supercharger. With the OD pulley it tends to wear them out, and they make a horrible noise at idle, oscillating.
I will say this, I didn't pay attention to the orientation of the part when I removed it, and getting all
the bolts to line up on reinstall was a real PIA. I could only stand in the position necessary for a while, before I got
too sore to continue, and it ended up taking multiple sessions, trying again and again to thread all the bolts.
Finally after a week of trying on and off, I got it. Wow, that was really a beetch!
I'd done it before no problemo, so very frustrating that I couldn't get it.
Still I mean, it's an 80 dollar part (I ordered the INA one from RockAuto and ended up getting the
OEM one which is Lemforder I think) so how they can justify 1 grand is beyond me.
My lady's ML siezed the pulley and consequently ate the belt on her Ml350, so new pulley belt and tensioner, and
I got it done in like 20 minutes...go figure. Fortunately I was following her when it failed, we jumped in the car, drove
straight to the dealer before they closed and got it fixed before it got dark.
for the supercharger. With the OD pulley it tends to wear them out, and they make a horrible noise at idle, oscillating.
I will say this, I didn't pay attention to the orientation of the part when I removed it, and getting all
the bolts to line up on reinstall was a real PIA. I could only stand in the position necessary for a while, before I got
too sore to continue, and it ended up taking multiple sessions, trying again and again to thread all the bolts.
Finally after a week of trying on and off, I got it. Wow, that was really a beetch!
I'd done it before no problemo, so very frustrating that I couldn't get it.
Still I mean, it's an 80 dollar part (I ordered the INA one from RockAuto and ended up getting the
OEM one which is Lemforder I think) so how they can justify 1 grand is beyond me.
My lady's ML siezed the pulley and consequently ate the belt on her Ml350, so new pulley belt and tensioner, and
I got it done in like 20 minutes...go figure. Fortunately I was following her when it failed, we jumped in the car, drove
straight to the dealer before they closed and got it fixed before it got dark.
This unfortunately sucks. I already paid over $1000 to the dealership to replace one faulty tensioner several years back, and now mine is starting to warble again if I turn on the AC when I first start the engine. Fortunately I think it's about time to replace the supercharger as well (maybe the AC compressor too for good measure.)
Super Member
Joined: Jul 2002
Posts: 591
Likes: 3
From: Mid-Atlantic USA
W203 & W204 3.0L 4matics & MR2 Supercharger
Holy Crap! $ A grand for a tensioner? I recently replaced one of mine (m111 has 2)
for the supercharger. With the OD pulley it tends to wear them out, and they make a horrible noise at idle, oscillating.
I will say this, I didn't pay attention to the orientation of the part when I removed it, and getting all
the bolts to line up on reinstall was a real PIA. I could only stand in the position necessary for a while, before I got
too sore to continue, and it ended up taking multiple sessions, trying again and again to thread all the bolts.
Finally after a week of trying on and off, I got it. Wow, that was really a beetch!
I'd done it before no problemo, so very frustrating that I couldn't get it.
Still I mean, it's an 80 dollar part (I ordered the INA one from RockAuto and ended up getting the
OEM one which is Lemforder I think) so how they can justify 1 grand is beyond me.
My lady's ML siezed the pulley and consequently ate the belt on her Ml350, so new pulley belt and tensioner, and
I got it done in like 20 minutes...go figure. Fortunately I was following her when it failed, we jumped in the car, drove
straight to the dealer before they closed and got it fixed before it got dark.
for the supercharger. With the OD pulley it tends to wear them out, and they make a horrible noise at idle, oscillating.
I will say this, I didn't pay attention to the orientation of the part when I removed it, and getting all
the bolts to line up on reinstall was a real PIA. I could only stand in the position necessary for a while, before I got
too sore to continue, and it ended up taking multiple sessions, trying again and again to thread all the bolts.
Finally after a week of trying on and off, I got it. Wow, that was really a beetch!
I'd done it before no problemo, so very frustrating that I couldn't get it.
Still I mean, it's an 80 dollar part (I ordered the INA one from RockAuto and ended up getting the
OEM one which is Lemforder I think) so how they can justify 1 grand is beyond me.
My lady's ML siezed the pulley and consequently ate the belt on her Ml350, so new pulley belt and tensioner, and
I got it done in like 20 minutes...go figure. Fortunately I was following her when it failed, we jumped in the car, drove
straight to the dealer before they closed and got it fixed before it got dark.
Super Member
Joined: Mar 2012
Posts: 968
Likes: 62
From: San Francisco, CA
2005 c230SS
The serpentine belt tensioner is a $100 part ... My $1k price tag was due to the 4 hrs of book labor at dealership labor rates for replacement of that part ... evidently the compressor needs to come out in order to access the rear mounting bolt. For all M271 owners I would definitely recommend replacing the tensioner whenever you remove the compressor.
Btw I haven't replaced this myself yet ... I am not using the car as much recently so my repair plans are getting spread out. Next up for me is the weld crack in the exhaust manifold, then the AC compressor pulley bearing (or just replace the entire AC compressor).
-- John
Btw I haven't replaced this myself yet ... I am not using the car as much recently so my repair plans are getting spread out. Next up for me is the weld crack in the exhaust manifold, then the AC compressor pulley bearing (or just replace the entire AC compressor).
-- John
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Newbie
Joined: Sep 2019
Posts: 1
Likes: 1
W212 E200 Year 2011 Sedan
HOLY COW, what a differance the new mounts made. My first newbie post (way back when) asked why this car was so loud... well, now I know... the mounts were trashed. My car is 10X quieter than it was before. There used to be a lot of clanking, ratchety, type noise on startup, at stop signs, at drive throughs... now.. all GONE. And as strange as it may seem... it sorta feels like it handles better.
There is still a rattling noise coming from the drivers side... and I'm assuming its because that mount is gone; and I can't get to it.
BTW, 115K miles on the car... for referance...
There is still a rattling noise coming from the drivers side... and I'm assuming its because that mount is gone; and I can't get to it.
BTW, 115K miles on the car... for referance...
MBWorld Fanatic!
Joined: Dec 2003
Posts: 3,275
Likes: 236
From: BC, Canada
2003 C230K Coupe Orion Blue
Replaced my engine and transmission mounts last year as part of a larger repair (crankcase breather check valve replacement). Photos and notes in link.
Mileage was 235k km. Everything was shot. The rubber on the engine mounts had basically turned into leather. The bottom rubber was cracked all around, and the top rubber had completely peeled away. Both mounts had also collapsed by 15-20mm and were leaking, though it was only obvious once I tilted and a pile of brown liquid spilled out.
Can confirm that the car now rides extremely smoothly. The engine used to vibrate all the time, especially when idling, but I had simply gotten used to it over the years. The difference is instantly noticeable.
Seeing the poor condition of the original mounts, I would recommend a much shorter change interval. Maybe 150k km? The PN I used was 2x 203-240-19-17 (as listed by FCP), but both came with the rubber dust boot. I imagine 2x 203-240-20-17 is identical other than maybe the inclusion of the aforementioned boot. All I know is that the 19-17 part from FCP included the boots. If the ones you order do not include the boot, just reuse the old ones. So while the car orignally had the boot on 1 side, I now have them installed on both sides.
The new mounts are of a different design and hopefully will last longer. Guess I can give an update in a few years.
The transmission mount was also in fair to poor shape. The rubber had cracked, and there was a 6mm sag. The PN I used was 212-240-03-18, which is what the parts site suggested.
Mileage was 235k km. Everything was shot. The rubber on the engine mounts had basically turned into leather. The bottom rubber was cracked all around, and the top rubber had completely peeled away. Both mounts had also collapsed by 15-20mm and were leaking, though it was only obvious once I tilted and a pile of brown liquid spilled out.
Can confirm that the car now rides extremely smoothly. The engine used to vibrate all the time, especially when idling, but I had simply gotten used to it over the years. The difference is instantly noticeable.
Seeing the poor condition of the original mounts, I would recommend a much shorter change interval. Maybe 150k km? The PN I used was 2x 203-240-19-17 (as listed by FCP), but both came with the rubber dust boot. I imagine 2x 203-240-20-17 is identical other than maybe the inclusion of the aforementioned boot. All I know is that the 19-17 part from FCP included the boots. If the ones you order do not include the boot, just reuse the old ones. So while the car orignally had the boot on 1 side, I now have them installed on both sides.
The new mounts are of a different design and hopefully will last longer. Guess I can give an update in a few years.
The transmission mount was also in fair to poor shape. The rubber had cracked, and there was a 6mm sag. The PN I used was 212-240-03-18, which is what the parts site suggested.
Last edited by slammer111; Sep 7, 2022 at 06:00 AM.
Newbie
Joined: Feb 2022
Posts: 1
Likes: 0
W203 - 6-speed manual transmission, year 2004 (facelift)
Hey jkowtko,
Did you notice anything different(vibration, noise...) when your tranny mount was replaced??
I just got my front 2 engine mounts replaced but didn't notice much difference or I was expecting too much?? Hoping to quite down my "rumble" and exhaust leak like noise by replacing my tranny mount next week....
BTW my 05 C230 has 102k miles.....
Did you notice anything different(vibration, noise...) when your tranny mount was replaced??
I just got my front 2 engine mounts replaced but didn't notice much difference or I was expecting too much?? Hoping to quite down my "rumble" and exhaust leak like noise by replacing my tranny mount next week....
BTW my 05 C230 has 102k miles.....
I know this is a very old thread, but my car's symptoms is exactly as you described: "rumble" and exhaust leak like noise. Did you solved the issue? Planning to change both the engine mount and the tranny mount soon. Btw, the engine is M271 inside my W203 manufactured in 2004. It is a facelifted model with 6-speed manual transmission, and it is right-hand drive.
Any respond from any people here is much appreciated.
Junior Member
Joined: Jan 2016
Posts: 46
Likes: 0
From: Fremont, California
2005 C230 Sport
When I changed both my motor mounts and tranny mount, it made a whole world of a difference in smoothness for my car. I would recommend to always change both (motor and tranny mounts) when the time comes. My car is a 2005 C230 Kompressor sedan M271 motor with 170,000 miles in it.
Super Member
Joined: Mar 2012
Posts: 968
Likes: 62
From: San Francisco, CA
2005 c230SS
+1
Unless you live in a part of the world where there isn't much gravity ... seems like these need replacing after several years.
With the proper tools and a bit of time and patience these were relatively easy DIYs for me.
-- John
Unless you live in a part of the world where there isn't much gravity
... seems like these need replacing after several years. With the proper tools and a bit of time and patience these were relatively easy DIYs for me.
-- John
