Alex Dee

Hi

I have a 2007 c230 sedan with the M272 v6 2.5L. and it is making a terrible clicking sound that is perfectly consistant with engine revs. and sounds like its coming out of the rear of the driver side head(Canada car).when the car is warm the car get real loud. also when I start it I kick out a large puff of white smoke out the exhaust.

any suggestions, I seen some guy on you tube with the same noise in a M272 and he said that the cylinder walls in ONE cylinder is scored up. but that donest make to much sense to me. it is not the balancing shaft, my particular car is not effected by that mishalps ( I checked by vin).

any suggestions at all? I would guess valves but these valves cannot be adjusted at all.

thank you

pcy

Drop the drive belt and run the engine and see if the noise continues.

Is the coolant level going down?

dmac5356

I have the same problem with my C320. I have posted details elsewhere. Ideas include:

- Sounds like a stuck lifter?? Tick, tick, tick...
- Cam chain issue?
- Out of round harmonic balancer hitting something?
- Belt driven accessory noise? (try removing belt, start for just a minute to see if noise goes away)

So far I have not been able to figure out my ticking noise. Let us know if you do!

Alex Dee

I checked the Coolant, it was where it was suppose to be. and removed the accessory belt and the noise was still present. I very much appreciate the suggestions PCY, Thank you but the struggle continues .

Dmac5356, where in the engine does the noise sound like it is coming from? how long have you been driving with that noise (very important to me)? has the sound gotten worse or stayed the same?? I removed the valve covers and took a look, and there are no noticeable defects and when I spin the engine ( via crankshaft bolt) I cannot hear any sounds (I know I am spinning the motor at 3 rpm but it was worth a try). there is a guy on YouTube that claims the cylinder walls are all scored up... but it does not make too much sense for 1 cylinder to be damaged and not the other 5. take a look:
Thank you again
Alexander

02C240

Are you sure it's not the purge valve (just to make sure)? Looking at the video again I guess it it's coming from cyl 1 area...

dmac5356

I just bought my car about 3 months ago, and have only put ~4,000 miles on it. The noise does not seem to be changing over time. I checked the oil filter over closely, and it did not have any metal in it, so I don't think anything major is coming apart inside the engine.

I can't really tell where the noise is coming from in my car. One independent shop thought it was lifters on the passenger side. I then replaced all the lifters on that side as a DIY project. But that made no difference.

I then tried holding a long screwdriver on each valve cover while the engine was running as a "stethoscope" (be careful!) - ticking sound did not come through well, so I don't think it is the valve areas.

I removed my serpentine belt and ran the engine briefly, still ticks.

My harmonic balancer is out-of-round. Although the clearances are tight, I don't think it is actually hitting anything. I bought a new one anyway, but have not had time to install it.

Some people have suggested the timing chain or gear. That sounds like major surgery. I think a stretched chain would make more of a grinding noise as it rubs on things, not the tick-tick-tick I hear. Also, when I had the valve cover off I looked over the chain and there was no polishing where it might have been hitting something. The chain tensioner looked fine too.

The "scored cylinder wall" idea makes no sense to me. To make that much noise the piston would need to be very loose in the cylinder... much more than just scoring.

dmac5356

On my car the ticking varies directly with RPM. I did check the purge valve... I put my finger on it and could feel it vibrate when it is clicking, but it was much quieter and it does not tick directly with RPM.

Alex Dee

Thanks for all the INFO Dmac, I also checked my purge valve and it was not that. unless I looked at the wrong valve, my purge valve was not near cylinder 1 it was more to the driver side front of the engine bay.

My gf said she read somewhere that these cars car known for the catlitic converter element to separate from the housing, thus "making a sounds like a playing card in a bike rim" but how the hell do you test that? and as far as that scorded cyclinder thing I was thinking about jamming a camera down the spark plug hole to take a look.

I honestly feel better that your driving with this sound and are not getting any sense of damaging your car further. but I do really want to fix this because its a little embarrassing.

none the less I will keep close with updates on my finding

PelicanParts.com

Seriously might be a long shot, but it might be interesting to see if this makes at all a difference. I'm no expert, but I've had vehicles come in (non-Mercedes) and had something similar to this. Try doing a BG EPR treatment, change the oil, and put in a BG RF7. See if this at all quiets down your engine. Might just give you another idea of what could be going on. Might make a difference or might not. Not sure if you'll be able to find anything here, but can also take a look around our tech articles for assistance with diagnosing the issue as well. Good luck and let us know what you find out.

-Luccia

dmac5356

The purge valve is exactly where you thought it is.

A catalytic converter can rattle, yet probably not a precise tick-tick-tick that exactly matches RPM.

You could boroscope your cylinders (ie: jam a camera down the spark plug hole)... post your photos back here! I'll be very surprised if you find anything.

Yes - the ticking is embarrassing. My ticking seems more pronounced outside the car and at idle, or off-idle. It blends in with other sounds when going faster. I can barely hear it inside the car. Here is my ticking sound:


Another thought... years ago with a very different car I had a cracked exhaust manifold that made a very similar ticking sound whose repetitions also varied directly with rpm. Check out this YouTube video... maybe we have this guy's problem:

dmac5356

Alex - I just reread your original post. The white smoke and "louder when hot" symptoms are different than mine. My car just ticks.

I suspect you have a head gasket that is leaking. The white smoke is from coolant getting into the cylinder. The sound is the leak during the power stroke. Maybe it get's louder as the different metal parts heat up and expand at slightly different rates making the leak worse. The leak is between the cylinder and the water jacket, between the cylinder and the outside of the engine, or both. Symptoms might be oil in the coolant, coolant in the oil, coolant or oil leak to the outside, loss of coolant, coolant exiting the tail pipe (white smoke is steam) or visible exhaust staining near the block/head seam. The leak is probably very small... but should be fixed ASAP as it can erode the aluminum head and/or block.

rodrigra94

May help...I had the knocking on my M272 engine (almost identical to the video clips on this post). Anyway, all cylinders were inspected by local MB dealership and checked good. However, a couple of the main bearings were bad to include the shaft (all bearings and shaft replaced). Ten days later I picked up the car, it's been quiet as a mouse ever since.

Alex Dee

Hi all

sorry for the delayed response, the cracked exhaust is worth investigating, I am going to take a close look. as far as head gasket, I don't think that's the case with my car I do not have oil in my coolant or visa versa, and my coolant level is at its maximum as it was way before any of this jazz started. also the smoke is only on start up & only occasionally.

As far as bad crank bearings, did your oil light come on? because bad bearing should of dropped your oil pressure? I am temped to drop my pan and feel around.

Alex Dee

Take a look at this, albeit a newer m272

http://www.benzworld.org/forums/w211...er-dealer.html

Alex Dee

Good morning

I believe I figured out the puff of white smoke, my map sensor is not working correctly and is throwing an engine code.

dmac5356

Hopefully that will fix it, but I am not understanding the connection between a MAP code and white smoke on startup.

Alex Dee

Too much fuel,

rodrigra94

Main bearings...negative on oil lamp turning on, the car actually ran fine. The knocking/clattering was really evident in the AM while engine working its way to operating temperature.

dmac5356

Did the sensor replacement fix that part of the problem? Any news on the noise?

Alex Dee

Sorry for me not being present. But I've been ignoring the car. Anyway just pooped off the oil pan (lower piece where the oil pick up is) and seen tiny tiny shaveings, so I'll keep updating but 99%sure it's a main bearing. Which is terrible but at least I know the problem. So stop driving if you hot the loud tick

dmac5356

Updates?

Alex Dee

i took the motor out. this is the most i could see. Although you can see there is visual imperfections on the cylinder wall, it actually feels just as smooth as the rest of the cylinder walls.

i ve since put the motor back in and just been driving it, although the ticking is obnoxious certainly in Mercedes standards, what is a man to do. the car still technically works.

dmac5356

Wow - that sounds like a project!

It does look scored, but if it feels pretty smooth it's hard to imagine that is the cause. How is your oil consumption?

Was there any slop in the rod bearings? That's my biggest concern.

Alex Dee

i do believe my oil consumption has increased, but nothing exponential. and all the bearings were all fine.

atm my only recommendation for a fiz is ear plugs or turn up the mediocre sound system