Jkurth

I have a 2002 C240 Wagon with about 120k miles on it. There is a clicking noise that is coming from this little box behind the driver side headlight. There are two tubes that connect to this box and 2 wires at the top. It sounds like it is pumping/clicking and it is shaking while it does this. I noticed the same thing on my 2011 GLK350 but that one is not clicking.. any ideas? Is this connected to my vacuum lines or perhaps brake booster and should it be replaced if it is clicking like this? The other day, I got cut off and had to hit the brakes pretty hard- immediately after, there was no power to the engine. I would push the accelerator and nothing would happen- almost seemed like the engine turned off but it was still at about 1000 rpms and VERY slowly increasing. After turning the car off and then back on, it ran fine, but still noticed this clicking.

insame1

do some searching. It is the purge valve.

Jkurth

My research is now complete. How would one research this not knowing what it is? How would you go about your research? type clicking noise coming from engine? imagine how many results you would receive. not to mention the amount of time it would require to sift through all the various results. By going to a forum and posting an image of the part is in fact 'research'- in fact it is perhaps the best form. Got directly to those who may know.

Now although you answered my first question, there were others there remain unanswered, such as should this be replaced- There are no codes (yet) but it is clicking. Replace or can it be cleaned? Could there be any correlation between the purge valve and my hard braking/no acceleration. Thanks.

Paulmurphy

It's the evaporation solenoid that's it's normal sound, the function of this unit is to remove the build up of gas tank fumes and blend said fumes to the intake manifold for recycling .
you don't have a problem in my humble opinion.

insame1

http://bfy.tw/8zQm

First result on google. I literally typed in "w203 clicking noise from engine"


"Sometimes called the MOT valve (due to typical markings on it), the purge/regeneration valve works in conjunction with the vapor recovery canister as part of emission controls to ensure that raw fuel vapors are contained and not released to the atmosphere.

Yes, the ticking is normal. You can remove the valve and clean it with MAF spray if you wish, but that won't usually do anything for the ticking. The ticking seems to crop up after several years as the valve wears, since when the cars are new they simply pulse (you can feel it) with just a very low-volume noise, typically inaudible.

That said, unless the ticking bothers you, it can be ignored, otherwise replace the valve, it's nearly $100 though. It won't change anything in the car's operation, but it will be quieter.

OP, if your noise is NOT coming from the purge valve, but from the ABS, then you should get it checked out.

Good luck"


I dont post these comments to be a jerk. I just hate that all this info if already out there and relatively easy to find but, no one wants to take the time. Everyone just thinks they can come here post the same question for millionth time and we'll keep clicking out the answer like we get paid to do it or something.