This is my first time posting a thread here, a really awesome forum.

Have a 2004 W211 e320. I noticed recently that I can hear what sounds like light tapping sound from engine, when the engine is cold. It is particularly noticeable around 1500~2000 rpm. (the engine has about 71K)
when I drive. and the noise would become quieter once the car is warmed up.

I initially thought it was valve lifter or something related to it from threads I read here.

However; I decided to replicate the noise, by shifting transmission to neutral while stopped. slowly increase the engine speed to the rpm mentioned above. No Noise, the engine sounds smooth.

I am now curiously to see if anyone has had similar experience or possibly offer some advise on this.

thank you in advance.

 

how long have you had the car? Have you had an oil change performed on it yet, or is it still full of whatever the last guy put in? I would start with making sure you have the proper weight and type of oil, if you can not determine it has the proper oil, I would change it.

 

That is you have the same problem with mine...
That is call the leak coolant into trans fluild, and it destroy the trans, that is because the design of mercedes for the radiator ( google about this problem and you will know there are many many people got that). that sound look like your trans near to be died...
dont waste more time ( cus just 2 days after i got that and check by dealer, my trans just died for today), take to your shop or dealer near to you ( the best way is tow it, dont drive it any more)...
If you are lucky, u just need to replace radiator, torque converter, change all the fluid and coolant, ask them to do that at least 3 time, with that way you dont need to replace the trans ( if the trans is ok now)...
If you keep driving, and.....the trans is gone ....8k for the new trans from dealer..
If need more infor contract me: 408 512 0769 or mr_bin_can@yahoo.com
I will help you with my best

 

Thank you very much for your reply!

That is what I suspected too!, after reading several posts here at the forum.

however; I believe I have a Behr radiator instead of Varler radiator (not sure about the spelling, sorry) based on a lot of several posting.

besides the glycol test on the tranny fluid, how can one tell by looking at the coolant?

 

i think the dealer shoulld let you know( just make sure every thing ok cus maybe, the pre owner just only changed the radiator and didnt clean out the trans fluild...)

 

I agree that you need to get it checked out, I had similar (slight thumping noise by the right front tire) issues on my E350 however it turned out just to be the exhaust note and a slight leak in the HG... My question though has any of your Check lights been armed ?

 

no check light came on.

I will keep you guys posted, since I will be taking it in next week.

Based on what I found out from the forum and talking to a Indie MB shop

1. possible glycol contamination ( due to Valeo's badly designed radiator)

2. damaged conductor plate inside the tranny pan ( made of plastic part prolong to cracking which causes the noise)

3. damaged/worn torque converter

4. just low tranny fluid

 

Hey guys. I have a similar problem to this, but the slight ticking sound doesnt leave wether its in N, D or reverse. Its always there. I have taken it to 2 mechanics (one MB and one Private) and they both said this is a normal noise. When i got the car i swear it was perfectly silent and no ticking sound was heard. The noise is most heard when you pass a wall or barrier and when you drive into the garage. Its coming from underneath the driver side door (ticking is louder from the side of the car underneath the front right wheel then from the engine bay). So far what i found on forums here is that it can be exhaust leaking (but this would be alot louder wouldnt it?) lifters sticking or maybe one of the knock sensors stopped working. Always running Premium and fully synthetic oil. Does anyone have any help regarding this as its driving me nuts. Thanks

 

Engine ticking (piston slap like sound) when accelerating between 1200 & 3000 rpm motor mounts may need replacement to current, modified part.

Ticking always this may be purge valve located behind left headlight. Check this area to identify if this is the ticking you hear if so, you may need to replace valve to current part # 0004705593 (#10 in diagram).