HBC350

My 2009 also has a whining type noise that can be heard at slow speeds on accel. I never thought much of it since I've heard many other MB's with the same motor make the same noise.

I can say that the noise you described above is certainly not piston slap.

blackc230benzo

no not the whine itself. I was saying my noise is heard during the whine sound. It sounds a bit like tapping your finger on your thigh at about 8bps. Adding oil seemed to help, but it is still there.

Going to the dealer tomorrow anyways.

Boris_C63

OK. VERY IMPORTANT news regarding ticking/clicking engine noise on C63’s. I just dropped off my car at the dealer. They said they will get back to me tomorrow with the results of the inspection, however, I was given preliminary assumptions that I would love to share! As posted by many and reflected in numerous YouTube videos, the loud ticking/clicking sound is NOT NORMAL, especially if the frequency of the sound increases in relation to the accelerator, i.e. the more you press the gas pedal, the faster is the noise. If the noise is somewhat loud and annoying but the frequency DOES NOT increase by applying the accelerator, than in most cases it is the purge valve issue and is very easily fixed by a $70 part replacement. If the noise is high pitch, very noticeable and the frequency DOES increase when pushing the accelerator, then most likely it is the LIFTERS! Now, the lifters themselves might be the issue, or it could be as bad as an OIL PUMP that must be replaced. Hopefully, your cars are still under warranty, since that repair is very costly. My car makes noise only when it warms up, as opposed to some of you that have that problem only at the start-up, when the car is cold or has been sitting in a garage for a while. The assumption that during start-up the lifters are not yet filled with oil and that’s why they make noise does not work. In my case, the issue is that not enough pressure is created to adequately distribute oil from the oil pump into the lifters, which can cause permanent engine damage!!! Please take you cars to the dealer and have them look at the lifters if you are experiencing similar symptoms. I will keep you guys updated, as I hear more from the dealer tomorrow. Best of luck!

Here is how mine sounds via You Tube:

http://www.youtube.com/watch?v=3nlTDoIP2Oo

Interwebz

Man if you guys drove a car that was actually noisy, you'd think it was gonna explode or something. The high-string LS6 in my corvette sounds like a combination of 500 sewing machines in the passenger seat - all completely normal. the C63 sounds like a purring tiger in comparison.

sighting

Remember that the C63 has more sound dampening materials than the corvette has body panels

seriously though. it's still a luxury car and you should not hear new sounds from inside that cabin. Most of us know our cars enough to know when some sound pops up if ti;s new or not. Don't listen to anyone that says some new weird sounds is normal. If it was you would probably would not have noticed it prop up in the first place.

Even if the dealer says it's normal. Get him to put that down on paper with his response to you pointing out. Trust me when stuff goes belly up 1k after your warranty expire and it turns out it was that weird ticking noise you will be on your own unless you can prove that you told them about it.

every car is unique and most of the time the owners know and can spot small changes way before they become larger ones. my 2cents

blackc230benzo

Boris, my sound was much less noticeable than yours. I could only produce the sound with the transmission under tension. It turned out to be just very very low oil. No noise at all since the oil change.

Hans Delbruck

Key word assumptions, that your post suggests are fact. You haven't heard facts from your dealer yet.

Before you scare everyone, please be clear that you are hearing lifter noise AFTER your car has been driven, as opposed to lifter noise on the occasional cold startup, which is the case for the rest us... and IS NORMAL.

GHAZAN

i've heard it at cold start and while driving/acceleration, but no way near that loud. It stayed the same level.

Boris_C63

NOT trying to scare anyone! However, after checking my car, yesterday, the dealer said it were the "CAMSHAFT ADJUSTERS" that were making the noise, NOT the lifters, and definitely NOT the purge valve, so they ordered the replacement parts and the warranty DOES cover it. These are indeed the facts. If your engine sounds like mine, just go get it checked. That's all I said. I am just trying to help people. Have a great day!

ZephyrAMG

Thanks Boris for your help and research into this! Good to know!

SonnyakaPig

Regarding knock, some mornings when I start my car (cold start), my car will make some very loud and aggressive thumping sounds coming from right under the dash (basically where the engine is). The "knocking" or thumping can be heard for about a minute. It's can be felt as it shakes the car very slightly.

I always wondered if it was bad 91 gas, but I only fill up at Shell or Chevron. I have experienced this with a half tank of Shell gas.

But, my car's ECU has been scanned at least several times and there is no code history for knock retard.

This is interesting. I have never felt or heard this thumping sound when I was driving. I have only experienced it when I was parked and warming up my car in the morning (cold start).

At idle, our cars' run a lean AFR. Into the 14's I think. I believe that's perfectly normal and even expected, and as you increase in rpms, as what happens when you drive, more fuel is delivered and the AFR richens up.

So, to me, in my very amateur theory, I'm thinking that knock retard will only be triggered when the car is driving. When it's still parked and warming up, it's normal for the AFR to be lean and therefore, knock retard would be superfulous.

If that's the case, unless our cars are knocking when we are driving (from say, bad fuel) then we may never truly know if the car is actually knocking upon cold start.

That said, my car has recently had the purge valve replaced because it was creating lean codes and my car even shut off when I was pulling into my driveway a couple of weeks ago.

(*btw, if anyone remembers my gripe with my SA at the dealership, here's another jewel from him: I'm told him that I was scared that my car can shut off when I'm driving and he said, "don't worry, lots of cars do that, we had one lady -- 80-years-old -- that it recently happened to.) just wow.

Even though there were two lean codes, there were no stored history of KR being triggered. And that is the case even though according to my dealer, my car shut off by itself to protect itself from a faulty purge valve which caused a lean state. And still, no knock when driving.

When it comes to ticking, I think most of us understand that our valvetrains tick constantly. But, there was one video I heard in one of the other threads that sounded very different and much worse than the normal ticking I've heard in my car.

Hans Delbruck

I didn't mean to be an A $$... Thanks for the update, good your car is going to get fixed, haven't heard that one before! Just didn't want anyone to panic as a lot of us have experienced the occasional (and disturbing) loud tick tick tick on startup. The title of the thread does a bit of a disservice to our beloved engine, the M156, so I have to jump in and put my arm around it.

Boris_C63

No problem! I hope it will get fixed. Don't trust dealers one bit. Will see.

coladin

This is exactly how my car sounded this morning, itsat for a day and a half and it was about 18 degrees this morning when I left, hardly a cold start. It said that the oil was 29degrees this morning at stratup, the lowest I have ever seen. It ticked for quiet a while until it was warm. it was embarrassing for my car to sound like that when I was at a stop light and under load it sounded like this vid...or a 94 Cavalier.

Guess I should go to the dealer or did this go away after it warmed up and they said it was fine?