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2001 E320 - Motor Mount Replacement - You Can Do It!

144K views 124 replies 62 participants last post by  Eversurfer  
#1 ·
Rough idle? Rough acceleration? Really rough in reverse? Over 50,000 miles? I bet your motor mounts have leaked out all their oil and your engine is sitting on your frame - metal touching metal! I speak from experience.

I replaced my motor mounts today. It looks hard and was easy and took about three hours. Here's the details.

Remove the plastic splash guard from under the motor. There are holes in the crossmember that allow easy access to the motor mount's lower bolts. Remove the lower bolts. By the way, purchase a set of ratchet wrenches before you start - you'll want them when you work on the upper bolts. I would have paid alot for a set when I needed them!

The passanger side upper mount is best reached from the top. Remove it and the metal shield under it. This will take a while because you can get about 1/12th of a turn before running out of room between the motor and the inner fender. Thus the value of the ratchet wrench - there is not enough room for a socket wrench.

The driver side upper bolt is best reached from under the car. You might as well unbolt the AC compressor now, because you'll need to slide it forward to make a path big enough to remove the driver side mount later. The driver side upper bolt is best reached throught the space where the compressor was. By the way, only three bolts hold the compressor to the engine and it's easier to remove if you take off the surpentine belt before loosening the bolts. While wearing gloves, you can pull on the belt sufficiently to displace the auto tensioner and slide off the belt. Remove the upper bolt and metal shield.

I used a one foot long 2X4 and a floor jack to raise the engine. I positioned the 2X4 across the oil pan (perpendicular to the drive shaft) and raised the engine about 1 inch.

The passenger side mount is removed to the rear over the stearing rack and the driver side mount is removed to the front where the AC compressor was. Both are a tight fit.

I had to raise the motor another inch for the new mounts. Be sure and line up the little post on the top of each mount with the slot it fits in. You'll know what I mean when you're doing this repair.

Don't torque the bottom bolts until threading the top bolts or the top bolts may not line up well. Tighten all four bolts, bolt on the AC compressor and attach the splash guard.

I was able to pull the surpentine belt tight enough by hand (in a glove) to move the auto-tension pulley over far enough for me to put a screwdriver handle in the space between the tensioner pulley and the water pump pulley. (This tip should suggest how accomplished a mechanic I am!) This creates just enough slach in the serpentine belt path that you can get it back on. Remember to remove the screwdriver!

Start your car and enjoy being amazed at the improvement this repair makes. It is worth the trouble - just not worth the hundreds of dollars of labor charges everyone wants!

Good Luck - you can do it!
 
#4 ·
I just had mine done (98 E430) by a local indy...wish I would've done them myself.

AllData lists 2.4 hours per side, so the garage quoted me based on just under 5 hours. I happened to come back in about 90 minutes and they were already done! I checked and it looks like they were done properly. An interesting negotiation ensued with the shop manager that wasn't very satisfying.

Does the factory procedure call for a different approach? I know AllData is frequently "off" but this seems excessive....

c
 
#5 ·
Flat rate...

Actually, Curt, that's pretty typical. Most every repair that can be done is based on flat rate, which is pretty much the time it would take a competent mechanic with the proper tools following a standard procedure to do the job. Of course once they've done it several times they've learned all kinds of tricks and shortcuts, sometimes they make or modify tools to speed it up. Then the flat rate is much more profitable. The only way around that is to pre-negotiate and most shops won't do that. Their point of view is you agreed to a set price and their competence is what saved them time, you're paying for their competence as well as the job itself.

For a different take on flat-rate and shortcuts, I had a friend who was a mechanic in Tucson, had a mid-80s Jag in his shop one day, he was pulling the engine and tranny. I asked him what the heck he was doing and he said, "heater core". Turns out that the flat rate for the heater core was something like 24 hours because you have to disassemble the whole dash. Then you have to try and get it all back together without missing one of the millions of fasteners and not pinch any wires, etc. And hope you don't have any rattles. Good luck. Anyway, he'd learned that you can pull the engine and tranny, do a quick cut-out on the firewall, swap out the heater core, patch up the firewall, drop the engine/tranny back in and have it done in about 6-7 hours. He was honest with his customers, though, and didn't charge full flat-rate, plus he figured they should know he would be cutting their firewall. :)

Anyway, so long as the job was done right and they didn't exceed their quote, that's the most you can hope for at any shop. It hurts, but look on the bright side: at least you don't drive a Taurus. ;)

Take care and enjoy the ride,
Greg
 
#7 · (Edited)
I got mine replaced yesterday just in time before getting metal to metal. The Dealer charged me US$. 60,00 for each mount and i had the Bosch Car Service to change it. They charged me US$. 50,00 an hour.

The Bosch Tech lift the car on a dock and lift the engine a little and took both mount out from the rear. He slide each one(new) back inside and titghen it. After he lowered the engine on the mount and lowered the car

Over time the hydraulics will fail and the engine will drop slowly on the mount making the car idle rough. This is common for MB and VW cars.

Eddie
 
#9 ·
What kind and where did you buy your mounts?

Hi Patrick,

Thanks for the great info on changing the motor mounts. My 1997 W210 is running rough and I suspect it is time to change out the mounts. Where did you buy yours and what kind? Do you know if the procedures that you described would apply to my year/model?

Thanks!
 
#11 ·
The mounts on the diesel 210 chassis can be done without disconnecting anything else. You can access both the top and bottom bolts on both sides without removing or moving any other components.

Len
 
#16 ·
Found a pictoral from another website, not sure if its the same car.

Howto: Change engine mounts - MBClub Forums
That appears to be a Euro diesel model and hints in there suggest to me that it's an I configuration, either I4 or I6. The fact that the motor mounts are different numbers right and left confirm that it's definitely not the W210. Either way, it's pretty clear that MB has quite a bit of consistency across their model lines and I certainly enjoyed the bloke's humour.

The more I read about the motor mounts the more comfortable I feel with doing this when the time comes. Gotta get my stubby fine-tooth ratchet, though. :)

Take care and enjoy the ride,
Greg
 
#18 · (Edited)
Just finished mine. 2000 e430. It was pretty easy. 3 hours
No need to disconnect anything. I covered my alternator with a thick rag.
Stubby ratchet helps to get bolts out of the top of mounts but I had to use my 5/8 closed end wrench to break them loose. Other than that here are a few pointers
Use blue locktite on the bolts.
Bolts are 16mm on top 13mm on bottom or use 5/8 and 1/2
Watch the fan shround when jacking up the engine. The fan blades hit the shroud.
Jack one side up a little more while working on that side. I used a bottle jack and a stick.
Mark the old mounts on the front of them with a L and R using a sharpie marker before you pull them out.
Put the old mounts next to the new mounts and mark the new mounts L and R in the same place as the old ones. Huge help putting them back in.
 
#21 ·
No

and no.Get it on a lift and check for a blown gasket or a bad cat.Bad mounts lead to vibrations and excessive engine lift,not loud booming noises.Have it checked out ,before something checks out:eek:
:bowdown:
 
#24 ·
Report my own successful experience

Just finished my 1999 E320 Wagon (standard transmission, not AWD). It took me a total of four hours. (including about 1 hour for loosening the top bolt on the driver's side!)

To confirm: the top bolt is 16mm. Therefore unfortunately my I did not have a correct size ratchet wrench. I was able to loosen/tighten the top bolt with a low profile 16mm socket wrench.

I had to temporarily move the A/C compressor out of the way, but there was no need to disconnect any hoses or cables.

I did one side at a time, first the passenger's side and then the driver's side.
The top part of the motor mount has a pin that fits into a corresponding slot on the motor side, thus the motor mount "aligns itself".

Conclusion: Success. Now my car idles as smoothly as a new car.
 
#27 ·
2000 E320 Wagon

To confirm: the top bolt is 16mm. Therefore unfortunately my I did not have a correct size ratchet wrench. I was able to loosen/tighten the top bolt with a low profile 16mm socket wrench.

I had to temporarily move the A/C compressor out of the way, but there was no need to disconnect any hoses or cables.

I did one side at a time, first the passenger's side and then the driver's side.
The top part of the motor mount has a pin that fits into a corresponding slot on the motor side, thus the motor mount "aligns itself".
I took a look at mine yesterday on ramps, and I cannot see how you can get into the passenger side top bolt to get it off, from the top it seems like the airbox is in the way? The driver side seems like the AC compressor moved will allow access, but the passenger side is confusing me a little. I have a 5/8 ratchet wrench but seems too long to get in there. Do you have any other helpful hints? Thanks.
 
#25 ·
#26 ·
Nothing wrong with two, I like the variation. ;) However, Merging is not the answer anyway because it would ruin the threads the way the software handles it (basically it weaves the threads into one, aligning the posts chronologically...which would be a mess).

Theoretically a nice idea, but rather than worry about the two DIYs on engine mounts, I'd be much happier if noobs would learn to use the search function so we wouldn't have dozens of posts on "MAF code" "regular fuel" and all the others that come up all the time. :rolleyes:

Take care and enjoy the ride,
Greg
 
#28 ·
I managed to take out my passenger side mounts from below using the '5 Stubby tool' from autozone. See this thread and you will see the pic. No need to come from the top unless you want to remove airbox which ofcourse is a one minute job.

I used ramps and all my work was done from under teh car. Took me 6 hours but I am a newbie.

The hardest thing was torquing all bolts (50NM for top bolts and 35NM for lower bolts) as my torque wrench would not fit. Lower bolts are OK as there is enough space for a torque wrench.

Good luck...
 
#32 ·
Engine Mounts - Many Thanks! and more!

The engine mount DIY posts are old, so I want to make sure the proper thank yous get sent out.
Very big thank you to texas-patrick and G-AMG for their DIYs on motor mount replacement! I finished the job today and OH MY GOODNESS what a difference! I have seen posts where people have said their gas cars felt like diesels when the mounts failed. That was me - now the car feels like it rides higher, smoother and quieter and yes I am enjoying the ride! Awesome and I can't thank you enough for the guidance - you saved me major $$!

I do have some comments about the DIYs and other posts from other owners in hopes that I am making a contribution (I am a shade tree mechanic with no access to a lift):

1) Space in doing this job is VERY limited. I have larger than average forearms. Doing the passenger side mount wasn't that much of a problem when it came to space. The driver's side was different. I employed someone smaller than I with strength to get to, unbolt, and replace the top side motor mount bolt. I couldn't get to it seemingly no matter what I did. So, a small payment to a kid that needed it - no big deal.

2) If your mounts are leaking oil as mine were, BE CAREFUL getting them out from beneath the car. The oil can end up in places on your face you don't want. It missed me, but that stuff is nasty!

3) I used rhino ramps for the car and a 4 ton Craftsman hydraulic jack to jack the engine up higher for removal and re-installation. Once replaced, especially the driver's side, it is easier to let the engine back down to fit the bolts correctly.

This is NOT an especially difficult DIY - but BE PATIENT and vigilent and you'll be absolutely pleased with the result.

Again, thanks to everyone for their posts and help!! I'm hooked and pondering a higher level of membership!
 
#42 ·
Yours mounts on the 98 E300D



looked like mine and on the top side had cracks all over. 108K miles, not sure if they were org. as my driver side mount did not have the rubber boot cover.

Just a tid bit to add. I changed my tranny mount at the same time. So I loosened the MM's top and bottom then placed a jack under a 2 x 4 and lifted at the front of by bell housing, just enough to get the weight off my tranny mount. and loosened up the mount and swapped it out. I left the bottom 2 bolts loose with only a few threads for alignment, then dropped the jack. then did like the post said and swapped out my Over worked MM. On the 300D, did not have to remove anything, as all were easy to get at. Then went back and tightened down the tranny bolts. Changed the oil at the same time. I went to start the engine and I over cranked the engine as I could not feel or hear it. I took it for a ride and O'my > If I knew better I would have changed them 20k miles ago. I had my wife take it for a drive, same thing, I found her cranking the engine when it was already running. I just changed my transmission oil 3 months a go, and I am thinking I might change out the mounts again the next time I do the tranny fluid. Like in 60K miles.
Great DIY guys.

Bill