Yea I think I was getting ahead of myself. Years of owning a Land Rover, I've learnt to assume the worst.
I'm actually in Canada these days.. So I too share the "quality" fuel.

But, back on topic. Plugs came in today and I just swapped them out. Honestly the easiest access engine I've ever worked on for plugs. Dealerships are cleaning up if they're charging more than an hour labour.

I took it for a quick drive, and it felt a lot better. There is still a very slight rumble but I think I'm just looking for something at this point. The major vibe is completely gone so I obviously had a misfire. I'll drive it for a few more days through warm/cold conditions and make sure, but looks like it was an easy fix. It does make sense as the car is 4.5 years old with 35,000km. That says a lot of stop and go city driving so the plugs probably never saw self-cleaning temp.

Now to get the energy to pin point the booster leak, and we're problem free.

 

This is awesome to hear! Please report back if it comes back because sometimes my car is good and then it just starts doing it again. So now when you're warmed up and you turn the wheel on pavement it's totally smooth? that sounds like a dream! It is weird just because Mercedes interval is 90,000 miles for sparkplugs.

If you have good results I'll probably be doing this job, does this engine have two plugs per cylinder?

 

Yea I've also noticed it can be a little intermittent, but it will usually do it at least a few sets of lights per drive once it is warm. On my test drive, nudda. So here's hoping.

1 plug per cylinder. Bosch YR7MPP33 is the factory plug and what I replaced mine with. Pre-gapped (although it's always good to double check them).

I will keep you posted on how the next few days go.

 

These plugs are designed to go a long way but run them out of the self cleaning range in stop start short trip motoring & they will foul & you can't clean them other than putting them in for a long trip. A plug cleaning machine (grit blaster) will ruin them.

 

Quick update.. Plugs were not the fix. The vibration was still there just as strong I guess It was just a little wishfull thinking and coincidental timing.

Since the C63 guys have a number of reports of overfilling causing rough idle, I decided to check that. The last fill was done by Mercedes, low and behold they overfilled it (8.4QT instead of 7.4QT). Yet another dealership that doesn't pay attention to the 4Matic's smaller pan spec.

While I was under there, I noticed an oil leak around the transmission pan. So I said screw it and dropped it off at Mercedes.

It wasn't the pan, turns out it was the shift lock o-ring. Tech claimed it couldn't be accessed without removing the transfer case (would love to know if that is true). I ended up with a $1350 bill for repairing the leak and some TCM/ECM software updates.

I couldn't believe they charged me for the software updates. My car was at a Mercedes dealership for routine service just 6 months ago (before warranty ran out), Is it not common practise to check for software updates?

Anyways. It's all left a little bit of a source taste in my mouth. I guess I had higher hopes for the dealership being Mercedes, but I've learnt unless you're playing with the real big boys like Ferrari/Lambo, you're getting the exact same ****ty service as you would at Kia.

 

Wow sorry to hear about all this.

Shift lock O - Ring? That's a first I heard on 7 speed, I guess just some bad luck. And I'm no expert, but isn't the transfer case built into the transmission on 4matics? How could they remove it? I guess after they removed the transfer case that include a full transmission fluid refill?

Funny thing is, I don't even think people have had great experiences with Lambo or especially Ferrari dealers, I think they can be just as bad! It's just the dealer way...

 

He called it a shift lock.. He meant the Parking Pawl. As to why he said remove the transfer case, your right. I even knew they were integrated when I took it in but that never clicked in my head. I'm going to get under their and confirm the access was as difficult as he said.

I know we're jumping around between a few different issues here, but you seem to have the exact same problems as me for the most part. We both have 2008's.

Would you mind PM'ing me your VIN? I want to check your engine build date. I'm starting to wonder if both of our idle issues are balance shaft related being early W204's.

P.S. I think it's absolutely ridicilious the amount of reasearch I have to do on my own to make up for incompetent dealers.

EDIT:

Well look like thats not the case (at least not for me). Engine Serials up to 2729..30 468993 had the faulty balance shaft/sprocket. Mine is 30 740607.

 

I was reading your threads with interest on your vibration issues, as I have had this problem with my 2009 C230 4MATIC Sports Package (Canadian Model) since purchased new.

I too note some kind of vibration in the steering wheel when I turn at a very slow speeds. When my vehicle is warm the idle drops to 500rpm (ALL THE TIME). It is usually at this time when I am braked at the lights that I will feel a vibration in the steering wheel at 3 and 9, and an intermittent pulsing through the seat. As you mentioned exactly, when I put the car in neutral the vibration disappears. Needless to say, this has been frustrating as hell. I have worked out most of the bugs and warranty issues with the car, except this one.

I have had the car into two of the local MB dealers several times. Of course the computer shows no codes. One of the dealers replaced the engine mounts under warranty, which seemed to 'lessen' the problem, but did not resolve it. Another dealer said that the transmission mounts were perfect and that this was not the problem.

I talked to several of the service managers and one said that the problem is likely due to a low idle which is driven by the computer (and cannot be adjusted). He said that there were several models/makers of computers out there for MB.

I tried switching gasoline, but this did not make a difference. I use 91 octane.

I also noticed that when I use an accessory such as rolling down a window or turning on the rear window defroster, that this exacerbates the vibration for a few seconds.

I am not an expert on cars, but wonder if there is a accessory load issue at play here? Also why doe this happen only when the brakes are applied? Could it be an issue as described in the threads above?

My next steps are to have a few buddies take a look at the vehicle and for one to try and isolate the source of the vibration, as this would seem like a two person exercise. he I will take this info back to the dealer.

In the mean time, I have been slipping the car into neutral at the lights. very frustrating for sure.

Not sure if this is related, but I have noticed that over the past 2 years (On occasion), when I start my car about 2 hours after if had been running (i.e. driving to the gym for a workout then starting after the workout), that the car will sometimes idle rough as if it is about to die out. The idle would read maybe 700-800rpm, but the hood sort of shakes from side to side just slightly. Once the car warms up this goes away, but its very odd. Which makes me wonder if the vibration issue and this 'intermittent' rough start issue might be related. Any ideas?

If any of you guys have any more to share on this I'd love to hear it.

What if we all banded together and sent Mercedes a letter? My car is still under warranty for 7 months, and I have extended the warranty for 3 years.

t.

 

I was reading your threads with interest on your vibration issues, as I have had this problem with my 2009 C230 4MATIC Sports Package (Canadian Model) since purchased new.

I too note some kind of vibration in the steering wheel when I turn at a very slow speeds. When my vehicle is warm the idle drops to 500rpm (ALL THE TIME). It is usually at this time when I am braked at the lights that I will feel a vibration in the steering wheel at 3 and 9, and an intermittent pulsing through the seat. As you mentioned exactly, when I put the car in neutral the vibration disappears. Needless to say, this has been frustrating as hell. I have worked out most of the bugs and warranty issues with the car, except this one.

I have had the car into two of the local MB dealers several times. Of course the computer shows no codes. One of the dealers replaced the engine mounts under warranty, which seemed to 'lessen' the problem, but did not resolve it. Another dealer said that the transmission mounts were perfect and that this was not the problem.

I talked to several of the service managers and one said that the problem is likely due to a low idle which is driven by the computer (and cannot be adjusted). He said that there were several models/makers of computers out there for MB.

I tried switching gasoline, but this did not make a difference. I use 91 octane.

I also noticed that when I use an accessory such as rolling down a window or turning on the rear window defroster, that this exacerbates the vibration for a few seconds.

I am not an expert on cars, but wonder if there is a accessory load issue at play here? Also why doe this happen only when the brakes are applied? Could it be an issue as described in the threads above?

My next steps are to have a few buddies take a look at the vehicle and for one to try and isolate the source of the vibration, as this would seem like a two person exercise. he I will take this info back to the dealer.

In the mean time, I have been slipping the car into neutral at the lights. very frustrating for sure.

Not sure if this is related, but I have noticed that over the past 2 years (On occasion), when I start my car about 2 hours after if had been running (i.e. driving to the gym for a workout then starting after the workout), that the car will sometimes idle rough as if it is about to die out. The idle would read maybe 700-800rpm, but the hood sort of shakes from side to side just slightly. Once the car warms up this goes away, but its very odd. Which makes me wonder if the vibration issue and this 'intermittent' rough start issue might be related. Any ideas?

If any of you guys have any more to share on this I'd love to hear it.

What if we all banded together and sent Mercedes a letter? My car is still under warranty for 7 months, and I have extended the warranty for 3 years.

t.

 

Sorry for the delay.

Unfortunately I have no good updates. I've given up on the car and already making plans to get rid of it. First Mercedes. Last Mercedes.