CLK500 TWINS

Okay so as most of you know, I converted my suspension recently. I'm not sure if I'm just now feeling it due to the altered suspension or it just started.

When I start the car, I've noticed the car jumps slightly to the right. On a cold start, prior to putting the car into gear, I'll feel a slight tremble while idling. That's the only time however. I should mention, I feel no tremble or jump of the engine when accelerating. Let's say I drive to the store, park, come back out and restart it. The car still slightly jumps to the right, but no tremble during idle time while car is warm.
Does this sound like a motor mount? If it's jumping slightly to the right, which one is likely bad? I've read mount replacement can be a b*tch on the v12. Is there a simpler process that doesn't require lifting the engine. What is the typical cost of replacement?

biker349

when mine went it was like a bad front tires causing vibration from 0- about 50 mph.

CLK500 TWINS

So does this sound like it's maybe not a motor mount? What else could it be? Just normal and I'm only feeling it due to modified suspension?

ItalianJoe1

Easiest way to check is to look for fluid leaking from the mounts, if you can get to them. I haven't tried on mine to see if there is access with a mirror from the top but from the bottom you should be able to clearly see them. They are full of black hydraulic fluid, if the rupture it leaks out and is pretty obvious as it will leave streaks where it runs down.

Usually only the drivers side breaks, as it has to deal with the lifting force of the engine. The passenger side only gets compressed so it doesn't tear apart. But if you're changing one, change them both, the labor isn't much more at that point and it's not a job you want to do twice if the other one is worn out also and you still have vibrations.

biker349

what you describe could be an engine mount as well. take the advice and either look for yourself, or have a competent person check it out.

tusabes

You can check easy with the hood open , watch the engine while the car in drive with someone inside holding the brake and applying the gas while standing on the brake . If the engine jumps it's a bad motor mount

Don't stand in front of the car while testing like this ! Stand off to the side. No cheap or easy way to change mounts .

Welwynnick

I know where you're coming from, but whenever someone says the V12TT is expensive to maintain, I always beg to differ.

Raise the front end
Remove the covers
Undo six ABC hose brackets
Support the engine
Disconnect the steering rack
Remove six bolts
Drop the front subframe
Change the engine mounts

Yes, like everything else, its more difficult than other cars, but it isn't THAT difficult.

Nick

CLK500 TWINS

I'm not certain it's a mount as I don't understand why I would only feel a slight tremble after a cold start. I mean the engine does slightly rock to the right on startup at any temperature. But shouldn't I feel the trembling or even worse during any idling time or going from coast to heavy acceleration and back to coast? I feel nothing during normal idling times and the engine is super quiet. I went from a complete stop and gunned it off the line, felt/ heard nothing except the roar/ thrill of driving such a beautiful beast. Is there anything else that may cause a slight tremble only after a cold start? Stupid question but has anyone seen their engine while it's being started? Does it sit perfectly still or is it normal for it to slightly "jump" to the right? I watched a few YouTube videos on motor mount testing and the engine seems to jump up and pretty vigorously.
I have to try the visual test Tusabes mentioned. Nick I wish you were closer to me, if it is a mount, you seem to have done this before and me doing any of that myself I'm afraid is out of the question.

tusabes

I have a broken mount . Car is completely smooth except if you do the gas /brake test you can feel and see the engine jump

Welwynnick

If you were closer to me I would have fixed your ABC for you.

Nick

biker349

just a thought. if it turns out to be motor mounts you may want to change your tranny mount at the same time. others can chime in.

CLK500 TWINS

Yea that would have been ideal. You definitely know your way around this car without over complicating things. I wish I knew someone close by whom I could say the same about. Hell I wish I had the knowledge/ability myself. I'd love to be able to do my own work.

CLK500 TWINS

Really? That's interesting, I always thought they present themselves in very obvious ways. So is it a must do asap or can it wait? Will it cause any subsequent damage if you leave it be for a while?

CLK500 TWINS

I was wondering the same more or less. Really more or so how you would differentiate between a bad motor mount and a bad tranny mount? If it's a bad tranny mount are the symptoms similar? What about the flex disc? If that were an issue what symptoms would that present itself with?

2014CL600

Take it to a dealer and they will tell you what is wrong. How much could it cost you 125.00 for a diagnostic. If your motor mounts are gone, so is the trans mount. That is the W215 curse, you get beauty but you get troubles. These mounts are fluid filled, mine went out at 1,500 miles. Its age and sometimes its just defective parts. If you don't attend to it asap, you will break the neck of your radiator as there is NO give on the hose and it will crack if the motor moves upwards. Changing them requires the radiator to be drained, the engine lifted and I think they had to swing the front fenders out of the way to get the motor up. Either way don't let a jack leg work on it or he will for sure break the radiator neck.