JohnnyV12

Hi guys,

I couldn't find anything on changing the motor mounts on the earlier NA V12. My car is a CL but it should be the same procedure on the W220 and there are more readers here, I guess.

As the car gets older and some (minor) vibrations start to show up, I planned to do something good to the car and change these mounts. Even if they aren't the culprit, hey those things aren't that expensive and probably weren't ever changed before. It won't go worse - were his last words .
It would be the first time for me, but because I've successfully tackled some other things in the past and believe to have the right set of tools at hand, I would like to have a try.

I did some 'rtfm' and WIS tells me to disassemble half of the engine including a part of the exhaust in order to reach those mounts. But because I know that we have plenty of clever DIYers in here, there has to be a better... let's say easier way.

Like I said before, I couldn't find any information on this topic on this board regarding the M137. In my understanding this means three things:The major issue should be accessability of the bolts and getting the mounts out & in again. The V12TT ones are extremely limited in space due to the turbos, right? I hope that it will be somewhat easier because my engine lacks those turbos.

Long story short: what has definately to be removed and which special tools are handy/needed?

Thanks in advance for your answers!

Kind regards

Plutoe

It's all listed very clearly and correctly within startekinfo.com----all else you will be back

JohnnyV12

Thank you for your message. The site looks to me like an online version of the workshop information system (WIS) which I already have access to.
My original question was if anybody has done this task differently in terms of less time consuming and without disassembling the exhaust/generator/etc.

Plutoe

I don't know your experience, however mine is that WIS instructions, although do not provide the DIY shortcuts and FU's, are the quickest from a customers point of view.

tim687

Do you have any updates?

tusabes

That guy hadn’t been here for 4 years and prob his early v12 was junked as they all are eventually when faced with a big repair bill

JohnnyV12

I did sell the car some years ago when one of the ABC-hoses went kaboom. In the end I never changed those motor mounts. Sorry that I can't be of any help.

tusabes

That’s the fate of all early v12cars , as soon as a major repair bill comes up they get sold and parted out , as they are worth way more in parts then as a broken complete car

Kebowers47

As the owner of a 2000 S-600, 101,000 mi, I have to agree that most get parted out. I have had the rear ABC hose to the rear pressure accumulator rupture. I changed that hose ($200 part) and shortly after the hose to the left rear strut popped. I decided to replace all the rear hoses. A real big job. I do not know what the labor charge would have been (maybe 40+ shop hours), but the parts alone are over $3000. There are over 10 separate hoses/pipes and one must disassemble the entire rear drive train and body shields to effect the replacement. I would have thought long and hard about replacing the ABC with conventional springs had I realized the magnitude of the hose and accumulator replacements work.

tim687

Has anyone ever replaced these mounts themselves?
I do not have access to an motor lift so that will be an challenge

SilberGrau57

So, I'll share my experience taking my 2004 W240 with 81,000 miles to the dealer for an inspection of motor mounts and suspension bushings. I felt some play in the steering wheel and heard some clunking sounds in the front suspension when going over humps and bumps at low speed. I brought it in and a test drive didn't alert them to anything, then they did a visual inspection and found leaking in the motor mounts, subframe bushings and control arm bushings. Then came the quote to replace said items. They determined that the control arm bushings could not be replaced and the entire control arm assembly would need to be replaced. This was a hard "no." At least the subframe bushings and motor mounts could be replaced, but required "major surgery" to do so. In then end, I opted for the latter two services and upon getting the car back, there is actually more suspension noise than before! Maybe they just need to be "broken in" but I regret opting to have this done. My recommendation is to just live with whatever symptoms you are experiencing and chalk it up to having an older car/suspension.

wallyp

Learning how to effectively search on the forums will give you some help. These were from three or four minutes of searching...

https://www.benzworld.org/threads/20.../#post-7985745
https://www.benzworld.org/threads/s6...#post-16338866
https://www.benzworld.org/threads/ur...#post-18250906
https://www.benzworld.org/threads/10...#post-17896339

tusabes

Creeks and noises going over bumps and humps are indeed the control arm bushings and ball joints, very common problem on all these cars. And you can’t just replace the bushings you need to change the entire control arms.they have the ball joints and bushings already pressed in

tim687

I did find all of those threads, but the main conclusion is to let an shop do it 😂

wallyp

A couple of comments about squeaks and creaks...

One possibility might be the anti-sway bar rubber mounts. A squirt of rubber lube on the mounts sometimes helps.

Another possibility is a dry ball joint. You can buy a sharp needle that has a grease fitting on one end for small money. You then stick the needle into the rubber boots and pump a good grease into each of the ball joints. It might be a temporary fix - but "temporary" might be a year or two for a cheap, easy fix.

PrometheusFD3S

I just. removed all my ABC system & converted to coilers, an S500 power steering pump, 6 rib belt, front & rear anti-roll/ stabilizer/ sway bar (whatever you want to call it, in your part of the world & replaced the front trailing arms from ABC type (no ball point to accommodate for the front stabilizer bar end links) to the AirMatic type (has the forward facing ball joint to accommodate the end links for the front stabilizer bar.

it took longer than expected, but it wasn't because the car is hard to work on (quite the opposite, the W220 is incredibly easy to work on) it was the lack of consolidated information & realitivly non reactive community members in the forums/ Facebook groups.

I also did coil packs, plugs, fluids & calibration

Luckily for me, I had a 2-post lift & full access to shop tools, so that definitely made things easier.

the biggest issue of working on any car is making sure you have all the parts. & a clear vision of what you are wanting/ needing to do.

I put my car back together without doing the motor mounts, because I didn't want to wait for them to arrive in the mail.

but replacing the motor mounts on an ABC equipped W220 is a 1 hour job for both sides, with a lift.

On ramps/ jack stands, its a 2-4 hour job.

make sure you get the car up high enough to drop the sub frame

break the motor mount bolts & subframe bolts loose, then brace your. engine oil pan/ transmission bell housing pad, with a block of wood & a hydraulic jack (just support the engine weight, don't lift the powertrain assembly.

drop the subframe & motor mount bolts from the side of the vehicle, so when the subframe starts coming down, you aren't in the way.

lower the subframe enough to access to 2x upper motor mounts that hold the mount to the mount arms.

make sure the subframe doesn't come down too far, or the steering column splines will slip out of the yolk & you will need another person to help you reinstall the splined steering shaft into the steering column (requires 2 people, one inside the car & one under the car)

tim687

Now this was the reply that I was hoping to get.


Yeah, I do notice that too lately, alot of people disappear from these forums when they know what they needed to know.

What did you calibrate?

Because you can't lower the subframe far enough?

How do you tackle this?
I usually make a list of all the things that I needed to do, then find the involved part numbers in EPC, buy them and write them down (make sure to check WIS if there are one time use parts involved).
When preparing to do the actual work, I take that same list and add the WIS document numbers to the items and proceed with doing the actual maintenance

By the way, how to you properly diagnose that these engine mounts are bad? It's a torque monster, so the engine will move if you rev it a little

PrometheusFD3S

I calibrated the coilover ride height, dampening & rebound.

you can lower the front subframe plenty on jackstands, it’s just a ***** working on ramps/ jackstands. I am 38, I have spent years working on cars on jackstands & that will never happen again, unless I’m at a track event, making slight adjustments.

I literally just plowed into this project, searching the forums, digging up old posts from the boneyards & the good ‘ol trisl & error method.

ask me how many times I repeated steps, because I doubted that I re-torqued a bolt correctly & my anxiety triggered me to tear it apart & re-check.

having a large amount of space to lay everything out in an order of operation is great.

labeling hardware & grouping it helps a lot.

sometimes fasters will be longer than others, so note & picture which spots use the fasteners with anomalies that separate them from the rest of the group they are part of.

Example:

coilpack bolts (there are 3 different size/ type fasteners within this group) look at the castings on the coilpacks & you will see the castings are thicker on the top of the coilpack (that’s where the longer bolts go)

if you’re not sure about what length fastener goes into what depth location, probe the bolt location with a piece of rigid wire/ a straight pick or use a piece of welding rod.

buy a CASE/ BOX of brake cleaner or engine degreaser & spray the hell out of the engine, then proceed to blow it out with compressed air to break loose any gunk that can cause you headaches (do this outside, in properly ventilated areas)

CHECK YOUR LOCAL JUNKYARD TO SEE IF THERE IS A DONOR CAR IN YOUR AREA!!!

This is huge, for tackling tasks that you are too nervous to try on your car, go trial the procedure on the junker. + you can grab spare hardware & modules.

Welwynnick

From experience, if you're going to drop the front subframe to get all those things you can't reach otherwise, I recommend loosening but leaving the rear subframe bolts in place, and tilting the subframe down at the front. This disturbs the steering column the least, because the universal joint is very close to the pivoting axis formed by the two rear bolts.
Be careful you don't strain the power steering cooling return pipe on the left hand side, and the wiring to the PAS valve and the ABC pressure regulator on the right hand side, as they're clipped to the subframe.
If you're going to replace the motor mounts, I'd recommend changing the diverter valves while you're in there, plus the ABC pipe from the pump to the pressure regulator.
Nick