W221 S600 V12 engine missing?

Page may contain affiliate links. Please see terms for details.
Completely understand the shock at the cost - but it is a well-documented cost of running the V12's. It's their equivalent of the Active Body Control or Roof leak issues on the SL500. But the good news is that there are plenty of refurbished units around, and Specialists know exactly how to do the awkward replacement.

The nice thing about doing this kind of maintenance is you realise just how well these things are designed and built.

We've come a long way since the fabulous, in their own time, Jaguar V12's

jaguar-xjseries-engine-3.jpg

Dont want to upset the thread but pretty sure thats a either a 3.2 or 4.0 straight six jag lump :p
 
Thank you. Yes I'm going to change all the plugs. I'll do a full service on the car. I found ngk iridium plugs for just under £200 so I'll go for those as I read the ngk ones are better than bosch?
Yep
 
Dont want to upset the thread but pretty sure thats a either a 3.2 or 4.0 straight six jag lump :p

Of course it is, apologies, Chaps, such a dumb mistake, made on the iPhone hoof




Sent from my iPhone using Tapatalk
 
This is why I love car forums, such helpful people with good knowledge!
Thank you guys for all your advise and suggestions!

Like you guys mentioned it's one of the expensive jobs on the S600 and if they need doing there's places that charge 1k which I think is reasonable when you think once it was a 120k car. Most of us don't like to throw money away but when something needs doing we just have to get it done and let's be honest, there's so many times we spend money on things that don't need changing like amg wheels, bumpers ect :D
 
Just a quick update here but at the same time I'll ask for some advise.

I had the car plugged in a computer and there were no faults for the coil packs. It had some other faults (mainly due to the battery that was weak) and I cleared them all.

One fault that didn't clear was coolant pressure switch fault. I ordered one and it's arrived so I'll get that changed.

I also changed the transmission mount (very easy job) and the vibration that I felt through out the whole car has gone away. I still have the engine mount to do.

What I wanted to ask is, would the coolant temp switch cause the car shake on idle?
Could this shake that I feel on idle be caused because of the engine mount that hasn't been changed yet?

If it was misfiring, a fault would have come up.

Could it be maybe an air leak somewhere and it's causing this problem?

I know I should check all the hoses for any air leak but it's always good to get different ideas as well.

Another thing that worried me a little bit is that I read you could damage the coil packs when removing them to do the plugs! How bad of a design are this coil packs! Now I'm worried to even change them

All your suggestions and advise is appreciated
 
The engine mount can 100% cause vibrations throughout the car. Is it especially bad when you turn the car off/on as this is a tell tale sign?
 
The engine mount can 100% cause vibrations throughout the car. Is it especially bad when you turn the car off/on as this is a tell tale sign?

Actually when I start the car up and turn it off there is no shaking at all.
When I put the car in gear and press the brakes and accelerate at the same time, I can see the engine lifting on passengers side, it's very obvious the let mount has gone.
Doing some research online, I found out it's the worst side to change, nice! :rolleyes:
 
Hello guys.

Another update

I had all 24 plugs done on the car and the coolant switch.

I noticed the last coil on the passanger side was a little loose, all three wires still attached to the coil pack but I think when Mercedes changed the plugs last time they damaged it slightly and also the metal shiny bit was slightly open.
The car still shakes on idle but when it's warm it gets better.

No faults in the system for the coil packs but im a bit concerned with the coil that is slightly damaged?

I still haven't done the engine mounts but I will get them done soon (hopefully).
I bought a tool from America as I read without that tool it's impossible to get the mounts off.

I don't want to get another coil pack for £1k but if I that's what's causing the car to shake then I will.

I read online that quite a few people have had this problem with their s350 and s550, shaking on idle and it was either air flow meter or throttle body.
When I changed the plugs the throttle body was very clean, it looked like new and the ones that had problem with throttle body said their ones was blocked so I don't think that's my problem.

I also read that some guy put some engine oil in the fuel tank and filled the car up with fuel to the max and it cured the shaking!

I will also do a full service and I thought, could the fuel filter be blocked?

As for anyone wondering how difficult it was to do the plugs on a v12 Mercedes, I'd say it was quite easy. I found the plugs on the cl500 more difficult to do than the s600. The only thing is that you have to be very careful when doing the plugs in the s600 as everything is so expensive, especially the coil packs so you don't want to break anything!

Also be prepared to get some new gaskets as they get stuck in the spark plugs and when you pull the coil packs out some can get damaged but they're not expensive from Mercedes. I got 12 for £40

I'll update the thread again once the engine mounts are done
 
Last edited:
Hello guys.



I don't want to get another coil pack for £1k but if I that's what's causing the car to shake then I will.

The most reliable sign of a failing ignition system is misfiring under load.
 
Hello guys.

Another update

I had all 24 plugs done on the car and the coolant switch.

I noticed the last coil on the passanger side was a little loose, all three wires still attached to the coil pack but I think when Mercedes changed the plugs last time they damaged it slightly and also the metal shiny bit was slightly open.
The car still shakes on idle but when it's warm it gets better.

No faults in the system for the coil packs but im a bit concerned with the coil that is slightly damaged?

I still haven't done the engine mounts but I will get them done soon (hopefully).
I bought a tool from America as I read without that tool it's impossible to get the mounts off.

I don't want to get another coil pack for £1k but if I that's what's causing the car to shake then I will.

I read online that quite a few people have had this problem with their s350 and s550, shaking on idle and it was either air flow meter or throttle body.
When I changed the plugs the throttle body was very clean, it looked like new and the ones that had problem with throttle body said their ones was blocked so I don't think that's my problem.

I also read that some guy put some engine oil in the fuel tank and filled the car up with fuel to the max and it cured the shaking!

I will also do a full service and I thought, could the fuel filter be blocked?

As for anyone wondering how difficult it was to do the plugs on a v12 Mercedes, I'd say it was quite easy. I found the plugs on the cl500 more difficult to do than the s600. The only thing is that you have to be very careful when doing the plugs in the s600 as everything is so expensive, especially the coil packs so you don't want to break anything!

Also be prepared to get some new gaskets as they get stuck in the spark plugs and when you pull the coil packs out some can get damaged but they're not expensive from Mercedes. I got 12 for £40

I'll update the thread again once the engine mounts are done
Do you have a link for the tool from America?
 
Hello
Under load is driving or on idle?
Sorry if its a stupid question.

'Load' is a synonym for torque. At idle the torque generated matches exactly the engine's internal frictions. To accelerate the vehicle, a much greater level of torque is required which is achieved via increased internal pressure in the working cylinders. It is in trying to introduce a spark into this increased pressure that a failing ignition system will falter.
 
Update

Engine mounts done last night. Nearside mount completely split and offside wasn't great either.

I will post a thread "HOW TO" because if I just say here how long it took to do both of them, I wouldn't be surprised if all of you don't believe me. Once I post the thread, how to, I have a feeling a few people will love how simply the top mounts can be changed and in such short time in this V12 engines
 
Well it has taken over two months for the engine mounts to be changed,something I pointed out in post 7,it will be interesting to find out how long it took to change them,with the car shaking then changing the engine mounts and gearbox mounts nearly always cure the problem,I do envy the op for having a W221 S600,I nearly bought one having been pointed towards a great example by my local indy, but it was sold by the time I got there,as for weak batteries, well we all know how crazy that can make a MB behave,I hope the op is going to post some pictures.
 
Well it has taken over two months for the engine mounts to be changed,something I pointed out in post 7,it will be interesting to find out how long it took to change them,with the car shaking then changing the engine mounts and gearbox mounts nearly always cure the problem,I do envy the op for having a W221 S600,I nearly bought one having been pointed towards a great example by my local indy, but it was sold by the time I got there,as for weak batteries, well we all know how crazy that can make a MB behave,I hope the op is going to post some pictures.

Oh wow I didn't realise I asked 2 months ago about this!

The job took 1 hour and 45 mins in total and no I am not kidding!

The left engine mount (passenger side) took 15 mins to get out! The drivers side took a bit longer as we had to disconnect the steering colum and we dropped the steering rack, just took the bolts off so it was hanging. Once we had the left engine mount off we relaxed a bit as we figured it wouldn't take us 13 hours like some people had said online. If we do this job again on another s600 it can take a bit less time without rushing the job

I had the new engine mounts for over a month in the boot but I have been so busy and to be honest from what I read online I was dreading doing this job and in a way i was avoiding doing the mounts. The S600 is a project car that I'm not in a rush to do that's why the progress has been slow. Once I post the new thread it might be a good idea to make it sticky for anyone in the future that would want to do this work instead of paying Mercedes crazy money.

By the way, the shaking has gone away with the new engine mounts

Also one more thing, you don't need the special tool they mention online. I bought it from USA and I still have it in the box unopened. They say without this tool it's impossible to do the job but you don't need it, save your money.
 
Last edited:
I hope the op is going to post some pictures.

I'll post some pics once it starts to look a bit better, at the moment it doesn't look very pretty because the s65amg bodykit is black and I've only fitted the rear bunper so I could fit the AMG exhaust tips.
I took the rear boxes off and it sounds nicer now, not too loud but enough to hear it coming.

One more thing that I learned which I thought was quite cool and it shows how far Mercedes thought when designing this cars is that, if you look at the S class, the AMG tips, they are flash with the bumper, you cant see fully the amg writting and that's how I fitted the exhaust but when I went for a test drive ( I must add, it was a spirited drive :D) I went to see the exhaust and it had come out about 1inch from the rear bumper! At this point I was a bit upset as I wanted the exhaust to look oem and couldn't understand why it was sticking out but once I let the car cool down for 15 mins or so the exhaust tips were flash with the bumper again. Anyways I thought i'd share this with you all as I thought it was quite cool and in all the years I had never seen an exhaust expand like that and it does cool down very quickly.

I also bought a private plate for it, soon to be revealed what it says.... it involves my OCD :p, it matches my other private plate that says TOO OCD
 

Users who are viewing this thread

Back
Top Bottom