Hello all,

Firstly i am a long time viewer of these forums but have never posted here before and just recently purchased a 2010 model E350 Cabrio.

I have owned the car for a few months now but noticed after delivery of the vehicle from the dealership there is a strange noise which begins approximately 20 sections or so after start up of the car.
I know when it comes to trying to explain the type of noise on an online forum it can be quite difficult of course lol but what id say is it sounds like a light pinging type of noise maybe.
Definitely sounds like something that is making the noise has to do with rotation of some sort.
At engine cold start you begin to hear the noise after about 20-30 seconds later and once selecting the R or D gear and with the revs of the engine lowering down id say the noise slightly increases.
If i rev the engine slightly in P or N the noise goes away completely.

Im almost positive well at least 95% sure that when i first went to look and vehicle which was a few times before i made the purchase and plus test drive it i couldn't hear that particular noise. TO be honest the engine was working so smooth and quiet that it was difficult to actually tell if the engine was running at all!
The day when i brought it home and parked it...the next morning when i went to start it i heard that strange noise immediately.
I checked in the service books and it showed the dealer had the car serviced so i was thinking perhaps they put the wrong engine oil grade in it??? I changed the oils & filter again my self with Fully synthetic 5w-40 oils but the noise is still there. Decided to change the engine belt thinking maybe it was that but yeah the noise is still present.

To be honest i haven't been able to relax comfortably since picking the car up as im being paranoid something major could be wrong now??
Has anyone ever experienced something similar to this kind of thing?
Its a 2010 model (hockey stick led day running lights) with the 200kw V6 3.5L engine and has 83,200 kilometres and have been running 98 octane fuel.

Besides that weird noise im hearing the only other thing I've noticed is something when selecting the R gear the back up camera just shows black on the screen but besides all that i think everything else is working fine
Just really havnt driven it much as im a little worried with it that's all.

Would appreciate any feedback or info.
Thanks in advance.

 

 

 

That will probably be my last resort indeed.
Since i have no prior knowledge to these Merc engines i was just curious to hear any info from other owners as to be honest sometimes i feel more comfortable trusting other forum users's advice/opinions.
The one thing that has me super worried is after doing a bit of online search i discovered the sprocket problem the 3.5L engines can have but not sure if up to the year model mine is if that particular common problem was solved or not??

I was totally confused about the screen as well when i first picked up the car as with my other cars even if the screen is off when selecting reverse the cam feed would turn on the screen...but yeah this problem that I've noticed with the E350 the radio is on and when selecting reverse ill see the bottom line on the command screen with has the Return/Back icons etc its just the feed from the camera is completely black pretty much like no signal is getting through.
Maybe something or a cable is loose in the trunk because its not happening all the just random.
Actually come to think of it ive noticed it always works fine when leaving the first time from home and it might stop working after a few hours of driving around. Hmm

 

When you say the radio has to be on, do you mean that literally? In my car, the COMAND screen has to be on in order to view the rear camera input (after all, that's where the video feed is routed to), but the radio definitely does not have to be on.

 

What i do is i just have the radio on mute when the COMAND screen is on... unless there is another way of having the screen on for the backup camera/bluetooth but radio functions turned off?

 

In these cars, the button labelled "Mute" is somewhat misleading because its function is to actually turn on/off whatever audio source is currently playing. If it only muted the sound, then audio from non-radio sources (e.g., USB, CD, etc.) would continue to play (albeit silently) and when you turned the mute off, the audio wouldn't resume in the spot where you muted it. This is not the case; if you're halfway through a song on a non-radio source and you press "Mute", playback of the song stops in that position and then resumes from where you left off when you press "Mute" again.

 

Ahh that makes sense then if it works in that manner.
Honestly i don't even think ive tested using the mute button when playing a CD to notice if it had paused it midway or not lol.
Ill just be leaving the COMMAND screen on always mute the radio when coming back home before switching the ignition off then.

 

Decided to give a shot at changing the engine oil over the weekend.
The used car dealership i purchased the car from had it serviced before i picked it up and used Penrite HPR5 5w-40 oil. I changed it now to Mercedes Benz branded oil MB229.5 5w-40.
To me it maybe sounds a little more quiet now that particular noise ive been referencing in my first post of this thread or im getting use to it!!! LOL

First file 'audio only' was taken about 2 months into owning the E350 so it had the oil from the dealership while the second video clip i took on the weekend has the MB oil.
In the first clip around the 4/5 second mark you can hear the noise im talking about and for the second clip around the 3 second mark you can sort of hear it.

I have been to a local mechanic which he sort of struggled to understand and hear the noise i was explaining to him (was on a busy road also) and he suggested might be the lifters? Can the lifters go bad at low km's? (84,000 km)
About a week ago i visited a MB dealership also and that one mechanic came out to hear it & he said it sounded pretty normal to him and that's how those 3.5L engines work normally.

The thing is though and im not 100% sure well maybe 95% sure that when i originally went to view the vehicle and test drive it (3 seperate trips in total with 2 cold starts) i never heard anything abnormal and found the engine to be working very quiet. Soon as though it was serviced and i picked up the car with the following morning starting it up is when i first heard the noise.

From the files ive included what do you guys think... am i hearing things or could something be wrong?