ML Engine Mountings

[psmart]

Numerous discussions recently about engine mountings on 270cdi engines causing vibrations through the car. Symptoms are normally vibrations felt when the vehicle is cold, or around 2000rpm when vibrations can be felt in foot and steering wheel.

Below are photos of engine mountings from an ML270cdi, twice diagnosed by a dealership as being fault free.

If you look at the mounting, the lateral movement rubber is indeed intact, the vertical rubber has vanished, hence the vibration. Rubbing marks are evident where the upper and lower components of the mounting have been touching.

nb) On an ML270, replacing the mountings is not an easy job because of the location of the mountings. Basically, front wheels off, arch covers off, underbody panels off, water reservoir, accelerator sensor, oil cooler, oil reservoir, oil filter, charge air pipe and catalytic converter clip all need to come off and the engine lifted with an engine hoist. Some of the bolts are difficult to get to.

 

[Andy Wr]

Thanks for sharing that with us, would you say it is still a DIY job as long as you use an engine hoist?

 

[panason1c]

On an ML270, replacing the mountings is not an easy job because of the location of the mountings. Basically, front wheels off, arch covers off, underbody panels off, water reservoir, accelerator sensor, oil cooler, oil reservoir, oil filter, charge air pipe and catalytic converter clip all need to come off and the engine lifted with an engine hoist. Some of the bolts are difficult to get to.

I renewed the mountings on my ML a few weeks ago...

No need to remove some of the above nor the need for an engine hoist..........Raise the front of the car and support with axle stands, remove the front wheels and underbody panels, remove the inner arch covers ...... use a trolley jack with a suitable wooden block to support the engine (Commonsense necessary when positioning the block under the engine!)...remove the 3 engine mounting nuts and then remove the engine support arm (4 bolts) ..........the engine mounting will come away .........repeat on the other side.

 

[psmart]

Panason1c, where did you trolley jack? The sump is aluminium and we could find no angle or support point which we thought would carry the weight of the engine without damage to other components.

The oil cooler was necessary to get the left engine support bolt access, unless you've got some fancy tools other than a Torx set, universal joints and flexi couplings! The left engine mounting support was a right *beep* to gain access to and remove. Even when hoisted, we had to remove the servo bracket to get the mounting/support out. The tension on the pre-cat to cat was quite high (we thought we could get away without disconnecting it, but once you started hoisting, the tension on it didnt look good).

The gearbox mounting was a delight to do

Andy, its a DIY job but it takes time, perhaps Panason1c can elaborate on his method a bit more as that sump looks mighty fragile to jack on.

 

[panason1c]

psmart, The wooden block was used at the front/side edge of the sump, perhaps i was a bit braver than you in trusting that i didnt damage it... ..it was, after all, only supporting half the engine weight...you see engines on garage floors all the time sitting on their sumps...

Not sure why you had to remove the oil cooler though, it wasnt necessary on mine..unless i had a more extensive set of tools (extensions, uj's, etc)

Regarding the bit ......" Even when hoisted, we had to remove the servo bracket to get the mounting/support out. The tension on the pre-cat to cat was quite high (we thought we could get away without disconnecting it, but once you started hoisting, the tension on it didnt look good)."...

I hardly needed to raise the engine once i removed the support arms bolts ...(probably the reason why i didnt need to remove water reservoir, oil filter, etc..) .just a couple of inches raised was enough to free the mountings

The whole job took me about one and a half hours, and that included coffe breaks.

 

[psmart]

psmart, The wooden block was used at the front/side edge of the sump, perhaps i was a bit braver than you in trusting that i didnt damage it... ..it was, after all, only supporting half the engine weight...you see engines on garage floors all the time sitting on their sumps...

..true, but I wouldnt trust an engine like that (been their years ago), I err on the side of caution these days. The blocks iron, but it would have been just my luck if I cracked the sump/interface with the block!

I think its more of a case of experience, your more current, I just tend to do the jobs when I get prassed off with dealerships! I think its all down to tools and experience, which at 1.5 hours to (please dont laugh) 9 hours.... ok, 3-4 hours was deliberating, getting the hoist, having pow-wows with the neighbours etc.... Your way more up on speed than me, my only saving grace is I do err with caution.

Not sure why you had to remove the oil cooler though, it wasnt necessary on mine..unless i had a more extensive set of tools (extensions, uj's, etc)

Couldnt get to the left support bracket right top bolt (on the support to manifold bracket) with the Torx Spanners or Sockets I had, even when used with UJs and Flexi-Joints. By moving the cooler, you could feed a double extension bar down directly onto the bolt. The procedure of Merc recommends removal of all these parts. We didnt think the engine would need to be raised by more that a couple of inches, to clear the mounting to chassis thread length, but the left mounting was v.difficult. In fact, the engine would only raise on hoist by about 3 inches, even at this level, the left support bracket wouldnt come out until the servo bracket was moved!

 

[psmart]

Panason1c, would it be possible for you to DIY or send to Parrot the information to add to his excellent post?

My quoted time is from start (unpacking tools etc) to finish (all cleared up and beer in hand)! Still, actual work time was about 3-4 hours, so your method would be ideal for others who go down this route.

Ive driven my ML now (changed injector settings several times, reset gearbox etc) and Im really chuffed, nice and smooth. Next task, shox, but given the state of roads over here probably new shox wont help.

 

[panason1c]

Panason1c, would it be possible for you to DIY or send to Parrot the information to add to his excellent post?

psmart, Parrot is free to copy my method of renewing the engine mounts onto his 'sticky' if he wishes, otherwise, anyone using the 'search' button will find the info here.

Regarding your previous reference to 'experience' .....It's probably worth mentioning that i do have 40+ years as a mechanic (Semi-retired in Spain now) and tend to approach some tasks 'my way' rather than 'the book' way which might explain why my time was considerably shorter than yours...........Having said that, you are a million miles ahead of me when it comes to 'changing injector value's', remapping, etc

 

[psmart]

It's probably worth mentioning that i do have 40+ years as a mechanic (Semi-retired in Spain now) and tend to approach some tasks 'my way' rather than 'the book' way which might explain why my time was considerably shorter than yours....

Explains why your advise has always been v.good and helpful, you cant beat hands on experience!

Im still looking for a 2nd ECU for my ML before I remap again, darednt risk wiping it like I did last time!!! For some reason, there are a swathe of 220 or Vito cdi ECUs, but very few for the 270/320!