Strange noise from under floor

There’s a strange noise when the engine is running from under the floor near the oassenger seat - I’m not sure if it’s fuel tank or ad blue tank related or pump related but it sounds horrendous.

I’m going to either get Assistance out to look at it or take it into the dealer
Anyone else had issues

It’s a 2022 model year v300

Did you work it out? I have the same van and awful vibration noise on the same are at low engine speed

Vaughnt said:

There’s a strange noise when the engine is running from under the floor near the oassenger seat - I’m not sure if it’s fuel tank or ad blue tank related or pump related but it sounds horrendous.

I’m going to either get Assistance out to look at it or take it into the dealer
Anyone else had issues

It’s a 2022 model year v300

Click to expand...

Hi I think I have the same problem- did you manage to resolve the problem?

Yes, same problem here on my 2021 300d AMG Line MP. I have striped every thing out and taken it to Mercedes service, it seems intermittent and from under the floor of the area directly behind the passenger seat, or it cold be in the seat belt mechanism behind the plastic cover. It’s difficult to tell.

If MB cure the issue I will post whatever I can glean from them

Vaughnt said:

There’s a strange noise when the engine is running from under the floor near the oassenger seat - I’m not sure if it’s fuel tank or ad blue tank related or pump related but it sounds horrendous.

I’m going to either get Assistance out to look at it or take it into the dealer
Anyone else had issues

It’s a 2022 model year v300

Click to expand...

Did you get you vibration issue resolved?

Mercedes Stoke resolved my issue, apparently it was caused by air conditioning pipework.

I also have the same issue on 2023 v300d with only 8500 miles on it. I will be asking Shrewsbury to have a look at it. This vibration noise is / was changing in frequency with change in engine revs? Only between approx 1100 and 1600 revs?
Were Stoke MB definitive or was the aircon pipework as my best guess to this point was exhaust mounting needed damping as resonating?
Also one other observation are all these 300d engines as it looks like it from the thread . Thanks in advance all