C350e - strong petrol smell in cabin from cold

[Darrener]

I've had a c350e from new (2016) and only expereinced this after my recent major service. I took the car back to the dealer and they changed a high pressure pipe. The smell went away that evening (driving home) but it was back in the morning. I've been back to them and they can't smell it, but have arranged to keep the car for a few days in the new year. Apparently they can't do anything over the Chrismas period. My workaround is to drive with the climate control in recirculate mode.

Hi I have had mine since October 2019 and had the same issues with the smell of petrol, took it back to the dealership and they said it was some kind of valve that was not working, however after two weeks same again but due to work only had chance to take it back this week, they are telling me they will fit a new fuel pipe but will have to wait maybe a couple of weeks for it to come from Germany, so i will update when i get the car back

 

[Rich45]

Hi I have had mine since October 2019 and had the same issues with the smell of petrol, took it back to the dealership and they said it was some kind of valve that was not working, however after two weeks same again but due to work only had chance to take it back this week, they are telling me they will fit a new fuel pipe but will have to wait maybe a couple of weeks for it to come from Germany, so i will update when i get the car back

I had the same discussion with Mercedes during my annual service in January. They ordered the part (from Germany) and installed it for free. I suspect it is something they know about. I actually showed them this thread when I took the car in to demonstrate that it is not an isolated incident. They handled it pretty well I think.

 

[superlite]

Ive had my c350e now a couple of years, its a 2016, soon after I bought it I noticed the same smell, brought it into Mercedes and they could find nothing, after a year and having its annual service I brought it up again, they pressure tested the fuel lines and found nothing. over the next year the frequency became more regular and brought it in for its annual service. went through the problem with the service handler and gave him part numbers etc. He was back in 5 minutes to tell me that MB would be covering the cost of replacing the high pressure fuel line.
much to my delight as the car was out of warranty. no smell since

 

[ming666]

Do the UK cars have the carbon filter in the fuel tank breathing system? This is a cause of fumes in the cabin if its blocked?
I ask because mine also has the petrol smell in the cabin sometimes. Usually from cold when the engine isn't running.

 

[ming666]

...

 

[Deleted member 126969]

Pretty certain that vapour recovery carbon canisters have been obligatory for quite a few years now, so yes, it'll have one.

It seems the cause for this so far has always turned out to be that faulty fuel line across the back of the engine.

 

[ming666]

Thanks. I'll have it checked out once this virus shenanigans is over

 

[ming666]

Update:
I had the offending fuel hose replaced by Mercedes in Tonbridge. Mercedes paid for it. I'll report back if it doesn't fix the problem.
They were aware of the issue but they cannot ask Mercedes to pay for it without first running the £179 diagnostic. So you have to do the dance. They were nothing but helpful though and I didn't have to pay the £179 because the diagnostic revealed what we all knew it would. BTW if you have the diagnostic for anything that you then have fixed with them the cost of the diagnostic comes off the bill which is worth knowing.
They also did a couple of recalls that I was unaware of while it was in.

For those that are interested the part is £13! The job is £230 inc. the part and VAT if Mercedes don't pay for it.

I first phoned Mercedes Gatwick who were pretty rude and unhelpful and although the end result may have been the same I really didn't want to give them any business after talking to them on the phone.

 

[Deleted member 126969]

These dealers and manufacturers are great aren’t they. Have they not heard of a thing called the internet? “oh, sorry sir, not ever hewrd of that fault” yet a 2 second google returns thousands of hits. They need to realise that the old BS just don’t wash any more.

Glad you got it sorted anyway.

Out of interest, do you happen to know the part number for the pipe? Sounds like a DIY job if mine develops that fault.

 

[ming666]

Well their hands are tied on the diagnostic thing if Mercedes head office require that before authorising doing the work gratis but they can be more or less helpful.

After telling the two dealers that there was a thread outlining the problem on the MB owners forum the responses were as follows

Gatwick: "We don't do diagnosis based on internet forums"
Tonbridge: "Here is our email address, send us the link and any more information you have and we will do our best to get it sorted for you"

The service manager at Tonbridge phoned me back to get it sorted (he was working from home, so i didn't get to speak to him when I phoned)

Part number A274070-3500 you also need a couple of clips that I don't have the part numbers for but fuel line clips will do it (just not jubilee clips)
I did have a look and at first glance it looks like it ought to be quite easy to replace. However, Mercedes quote two hours of labour for this and the guy who did it said it was much more fiddly than he imagined (I'm guessing it was his first go) so maybe something has to come out to get it in?

 

[Deleted member 126969]

Thanks for that. I just re-read the entire thread and saw that @grober had already listed the part numbers some time back.

It’s not so much that I expect a dealer to dive in without diagnosis, it’s the way they utterly dismiss any suggestion there’s a common problem.

Might well be an awkward job but if mine develops that issue I think I’ll DIY it. At least, I’ll dig in and see what’s what. I’ve repaired and built enough cars now to tackle most tasks.

 

[ming666]

Just a quick update
The new hose has completely eliminated the petrol smell.