stan_tetters

Hi All,
I have a frustrating problem with my 2015 S550 Coupe when filling with gas in that it doesn't accept a high flow rate. If i try and fill at full rate, it continually causes the pump to click off due to the back pressure, so i have to carefully squeeze the pump about half way and continually regulate. It is a frustration for me and a show stopper for my wife filling it up!
has anybody else experienced this? Hoping there is a simple solution.
thanks.

ttuite

It is a venting problem. One of 3 things come to mind. Either a malfunctioning solenoid to the vapor recovery canister. The canister is full of fuel. The rollover pop up valve has popped due to repeated over fueling. When you fill up, do you fill the tank all the way to the top squeezing every ounce in? If so, bad idea. It runs down the vent line and into the canister, filling the canister and eventually actuating the rollover valve.

if you are handy at all you can diagnose the problem pretty cheaply. go under the car and follow the vent line attached to the fuel filler hose to the evap canister. If it is easily accessible, remove it and see if it is full. If it is it will need replaced. If that doesn’t work it will need a person experienced in wrenching. It is important to remember that there is very little “Mercedes” about US required air pollution controls which this is part of. Any local repair shop should be able to handle this for you instead of going to the Dealer.

Depending on your level of experience there are YouTube and other videos that will walk you through it and possibly turn it into a home repair.

lexnoir

The poster above nailed it. Had the issue with a VW Phaeton. That car was full of gremlins and this was one. It was a vapor canister.