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So it turns out the mechanical fan is sitting close to the bottom of the radiator, and upon hard braking is getting close enough to actually hit the radiator. Yikes! Is it possible I didn't align my new motor mounts correctly when I installed them?
So last night I jacked up the car, checked the motor mounts, and found that they were perfectly aligned with the little "tab" nicely fitting through the heatshield that sits above them. They were also firmly bolted in place.
It is a bit difficult to diagnose the sound, because it only does it while driving, and seemingly while braking, but last night as I tested it around the neighborhood the noise would occur when I wasn't braking either. It also won't start making the noise until I have surpassed 30 mph?
Also making things difficult is the fact that the radiator already had indentations in it from when the motor mount was flattened and the fan contacted the shroud and so I can't really tell if the fan is hitting the radiator or not.
Does anyone know how much forward movement the engine has when driving (in inches?). I played around with the fan shroud (moving it around then going for a test drive), and actually bent the radiator support away from the fan, so it looks like I have almost 2 inches of clearance from the fan now. I also, by hand with the engine running, shook the engine back and forth, front and back, as much as I could on the mounts, and the most it would move in any one direction was 0.5", which would not be enough for it to contact the shroud.
So the noise persists. I gave up after about 1.5 hours last night to reconsider my options.
This noise only started happening after I changed the motor mounts, and if history is a judge, that means I changed something to cause this noise.
However, the noise, a "racka-tacka-racka-tacka-tacka-tacka-tacka" type sound.
My next step is to remove the fan, remove the fan shroud, reinstall the fan, and go for a test drive to either confirm or eliminate the fan shroud as the cause of the noise.
Any thoughts? Could I be mistaken about the source of the noise? I have a growing hunch it may be somehow tied to the ABS pump.
Is it possible that your new motor mounts have caused an incorrect angle in relation to your transmission mount resulting in the interference? I'm assuming your transmission mount hasn't been replaced.
This probably doesn't make any sense, but it's all I can come up with currently.
Is it possible that your new motor mounts have caused an incorrect angle in relation to your transmission mount resulting in the interference? I'm assuming your transmission mount hasn't been replaced.
This probably doesn't make any sense, but it's all I can come up with currently.
Thanks for the feedback. I should have added my transmission mount is only 3 months old.
I really am going nuts about this thing, but am renting the fan clutch removal tool from Advance Auto tonight and will try removing the fan shroud and driving around.
I am also considering trying to take a video of the engine compartment where the fan sits while driving so I can better see what is going on/how much engine movement is occurring.
I rented the fan clutch removal tool from Advance last night but unfortunately it was the wrong size. Kept slipping off the nut holding the fan to the output shaft. Will have to track down the right tool before proceeding.
I also contemplated pulling what I think to be the ABS relay in the right hand corner (driver's side) of the engine compartment to do a test run last night to see if that changed anything. Seems like a long shot but I wasn't sure if it definitely was the ABS relay so I held off. I think it is the black relay on the right hand-side (towards the back) in this picture. Anyone know?
Okay so I tried to make a video of the noise under the hood, showing engine movement in relation to the fan. It is pretty tight in there so it was hard to get a good angle with my iPhone and include an LED light.
Fast forward towards the 1:30 minute mark at which point I have just accelerated up to a little over 30 mph and as I apply the brakes the noise starts.
The video does not show any clear-cut sign of the fan hitting the shroud, but you definitely hear the noise.
Any thoughts? Apologies for the led light directly in front of the lens.
Okay so last night I was able to get the fan shroud off using one of the tools I got from Advance, and locking pliers for the nut attached to the fan clutch. Re-installed the fan and took a test drive this morning. No more noise!
Because of the proximity of the fan to the radiator and shroud it is very difficult to see where the fan is in relation to the shroud. I thought I had more than enough room, but I guess not.
For the time being, I am going to leave the fan shroud off. I know it is there for more efficient cooling, so I will see if it becomes an issue.
So I have had a chance to get some more seat time in the E55 since removing the fan shroud.
The rattling noise is almost entirely gone, however, it seems that between 30-40 mph if I hit a bump just in a certain way I will get a little rattling and then it goes away after a few seconds – it is not nearly as loud or as persistent as it was before.
This weekend I actually loosened up the motor mounts, checked their alignment (to ensure the little metal guide pin on the top of the mounts was properly positioned through the heat shield) and re-tightened the bolts on each mount.
This has been frustrating as hell – and I still feel like I haven’t totally solved the issue.
IanB – To answer your question, it is difficult, because it is hard for me to tell where fresh marks are and where marks are from prior “incidents”. The fan blades aren’t particularly banged up which is strange. The fan shroud has a flat portion on the right hand side (if you are facing the front of the vehicle) that rests up against the radiator (hard to explain) – it does have indentations/scratches from the fan contacting there. Hard to tell how recent. Additionally, the radiator, at 1 o’clock and between 5 and 7 o’clock, has indentations on the metal fins from the fan. Again, hard to discern if these are new or old indentations.
I am going to keep driving it and see if the noise gets worse. I have a hunch that as the motor mounts settle a bit from the weight of the engine the noise will dissipate but only more driving time will tell.
Basically, it looks like I bought motor mounts for the wrong chassis.
From my research (the best source I found was AutohausAZ's site), our W210 E55s actually had three (yes, you heard me right, three) different styles of motor mounts, and you need to refer to your chassis number to select the correct one.
I am still trying to figure out how different the various models of engine mounts are, but I have established I purchased the Lemforder mount (#2662401) which is for chassis # up to A8400000
My chassis # is A918077, so I should have purchased Lemforder mount (#2775501). See picture below of the different types.
I guess I will order the later motor mount style and see if that solves my problem. Any idea how different these parts are from one another?
BTW I will just add that the motor mounts I pulled out of the vehicle looked the same in terms of style/type as the ones I installed - so not really sure if this is the end of my issues or not.
Here is a little more information. Pasted below I have included the chassis number (which is the last six digits of your VIN), together with the correct Mercedes part number for the motor mount:
> Chassis #: below and up to A840001 – Mercedes Part #: 202-240-29-17
> Chassis #: A840002 through A962231 (instead of ‘A962231’ sometimes the part lookup states “through 6/1999” or June 1999, I guess to refer to the fact that this was the cut-off for this chassis style?) – Mercedes Part #: 202-240-44-17
> Chassis #: A962232 and up (instead of ‘A962232’ sometimes the part lookup states “from 6/1999”) – Mercedes Part #: 202-240-49-17
So I went ahead and ordered Corteco branded motor mounts from Pelican Parts tonight with part # 202-240-44-17. What a PIA this has turned out to be.
I spoke to a rep from RMEuropean and from Mercedes of Chantilly about the nuances in parts, and neither of them knew what the difference in the part I installed was (for earlier chassis - part 202-240-29-17) and the newer part. However, they both affirmatively told me I had installed the wrong part ().
I also confirmed by build-date by looking at the sticker in my driver's side door jam (April 1999) to be sure I didn't require the newerst style (part 202-240-49-17).
When I receive the new mounts I will closely compare the two to see what the difference is.
I'm not sure about the differences, but I'm assuming they vary in levels stiffness. They are identical in fitment. Did you order from autohaus? I ordered mounts for my W211 E55 there a few years ago they sent me E550 (non AMG) mounts. I didn't know and put them on and they were bad again after approx. 3k mi.
For my w210, I put on W211 E55 Corteco mounts. They are stiffer and I hope they last longer.
Last edited by desired_speeds; 08-04-2015 at 01:57 PM.
I'm not sure about the differences, but it may be due to varying stiffness levels. Did you order from autohaus? I ordered mounts for my W211 E55 there a few years ago they sent me E550 (non amg) mounts. I didn't know and put them on and they were bad again after approx. 3k mi.
For my w210, I put on W211 E55 mounts. They are stiffer and I hope they last longer.
Thanks for the feedback. I originally ordered my mounts from Amazon.com - which was bad on me for not doing sufficient research. I used the "Check Fit" option on Amazon - which I am sure is far from bullet-proof, especially on these nuanced parts.
I ordered the replacements from Pelican Parts so I am going to scrutinize the new mounts when I receive them.
Additionally, as an update regarding moving the fan shroud, yesterday I drove home in about 92* ambient temps with the AC running, for the first time I can recall, the auxiliary electric fan kicked on. It has never done that before. So clearly the fan shroud makes a difference in cooling ability of the mechanical fan, especially on those hot days. I plan to re-install the shroud once I get the correct mounts in and see what happens.
I've been through similar experiences. Once in a while simple jobs can turn into sanity checks!
I would make sure the mounts you put in were wrong. I doubt they would fit if they were wrong. Check the trans mount too for the correct part.
I have noticed you have not mentioned checking that the radiator is seated properly. If it isn't down all they way, you could get interference on the bottom end of the shroud.
Fortunately this is a simple job and the car is running fine most of the time. Something is wrong and you will find it. Be patient and don't throw physical labor at it before you carefully inspect everything.
Lastly, is it possible your fan or fan clutch is the wrong part?
Last edited by Schweinhund; 08-05-2015 at 10:22 AM.
I've been through similar experiences. Once in a while simple jobs can turn into sanity checks!
I would make sure the mounts you put in were wrong. I doubt they would fit if they were wrong. Check the trans mount too for the correct part.
I have noticed you have not mentioned checking that the radiator is seated properly. If it isn't down all they way, you could get interference on the bottom end of the shroud.
Fortunately this is a simple job and the car is running fine most of the time. Something is wrong and you will find it. Be patient and don't throw physical labor at it before you carefully inspect everything.
Lastly, is it possible your fan or fan clutch is the wrong part?
Thanks for the feedback. The encouraging words do help believe it or not. My wife and I are doing a week long trip to Cape Cod starting this weekend and I was really looking forward to taking the E55, but alas it seems that will not happen with the ongoing issues with the motor mounts. Oh well.
I have confirmed definitively that the motor mounts I installed are not correct for the chassis # of my E55. From looking at pictures of the different mounts that are available for our cars, I actually think many of them look the same, but they have different spring rates. I find it hard to believe that is the case, but I was getting the tires changed on my wife's Jetta today and talked to the service rep who was helping me. I like this shop a lot (independent family-run place called G&C Auto in Chantilly), and they work on European makes frequently. He said AMG models have very specific parts, down to the VIN/chassis #, and can be very finicky if you install the wrong parts.
My new mounts will be here tonight and I will likely try to install them tonight. So we will find out! Will post up pics of the two different mounts.
i put genuine w211 E55 AMG Kompressor engine mounts in my C43, car felt more solid after.
less vibrations, hopefully these mounts will last longer than c43 mounts coz they are made stiffer for w211 E55AMG
Bad news. Installed the new mounts last night. The noise is virtually unchanged. When stopping hard I can still hear what sounds like the fan hitting the shroud. I am about to break down and take it into a local shop I like for an assessment to see if they can crack the code.
Pretty disappointed to spend the coin on two sets of mounts and it not resolve the issue. The annoying thing is because the noise only occurs when the vehicle is in motion, it makes it very difficult to diagnose.
Took some pics. The old mount I removed is on the left (Lemforder brand, part # 202-240-29-17) and the correct mount for my chassis is on the right (Corteco brand, part # 202-240-44-17). As you can see, the mounts are different, but in comparing them closely the dimensions are basically the same.
Also for anyone thinking of doing this job, this is what my set up looked like mid-install. Don't be fooled, the weight of the car is on the two jack stands you see - NOT the bottle jack. I only have the bottle jack pushing the engine upwards an inch or two.
Pic of the old mount still installed (Driver’s side)
Pic of the new mount installed (Passenger side)
My trusty canine companion consoling me after a third evening spent fiddling with engine mounts without success, and scolding me for buying a high-mileage used Mercedes
07-29-2015, 09:53 AM
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