Hi All,

Have a strange issue with my 2015 S550 4matic. Love this car.

When I go to fill gas, I place the nozzle in and click the little latch so that I do not have to squeeze the trigger continuously (This is something we all do). Now that it is a colder temperature in the Chicago area, I set the filling nozzle and go back to sit in the car while it fills. However, recently, when I set the latch so it fills, it clicks off like the tank is full with only dispensing a few gallons of gas. I have to reset it continuously in order to fill the tank. In fact, now I'm not really ever sure if the tank is truly full bc it clicks off so frequently. I just have to guess if it is full. It's annoying to have to constantly get back out to reset the latch to fill gas or have to babysit it.

Has anyone else experienced anything like this?

Appreciate your thoughts!

 

Try pulling the filler neck out of the opening slightly...

 

This is what happens when the tank has been overfilled. There is a charcoal filter/canister and if the charcoal gets displaced from an overfill, the gas nozzle keeps clicking off even if the tank is not full.

The solution is a replacement of the charcoal canister at the fuel tank. It’ll cost a few bucks at the dealer. Or if you’re under warranty they may do it under warranty coverage. The best way to avoid this is to NEVER TOP OFF YOUR TANK after automatic shutoff.

My problem occurred when I filled my tank with spare gas from a storage container and I inadvertently overfilled to overflowing. Lesson learned.

 

Is it specific gas stations? Different car, but my current AMG is the first car I've owned that requires me to fiddle with the nozzle every time before it starts properly. It's specifically at Shell stations in my area. They all have awkward nozzles now that don't seem to fit properly, and it's difficult to make a good seal. If the seal is not proper, then the pump clicks off. I had no issues with their previous nozzle design and I also did European Delivery with no issues fueling all across Europe. Shell is my preferred brand, but their nozzles are really annoying me. Once the tank is full, I also have to twist and pull to get the nozzle off. It first doesn't make a proper seal, but once the seal is good, it's so good that there's a vacuum and the nozzle can't be removed easily. What seems to work most reliably is if I hold the nozzle in place for a bit before letting go. That seems to seal it properly and then it won't click off as soon as I let go. One of the pumps at the station I frequently fuel, still has the previous nozzle design and I always use that one if its free. Never having issues with that one. I was trying to find a picture on Google, but haven't found one. The nozzles that are giving me trouble are those that have like a rubber snorkel on them and the nozzle only sticks out at the very end of it, so you have to push it in and compress the snorkel. Don't know what they are called.

 

I have also learnt that you should not overfill your fuel tank after the system shutoff . Perhaps, a stupid idea but give your car a jiggle and try again

 

My car did it as well. As I was about to clean the charcoal filter (there are instructions on the “other” MB forum), I decided to try another gas station. Seemed the problem was limited to that first station after all. Haven’t had that issue since in about 20 fillups.

 

This happened to my 2014 S550 when it was still under the extended warranty. They had to replace the charcoal filter/canister and they would not cover it since it was operator error. I think it was around $650 parts and labor.

The only way I could fill the car was very slowly no matter what gas station I went to, or any fiddling with the gas nozzle.

 

Ditto. That is what I was going to say. Certain nozzles may have a steeper curve in them so that when the nozzle is fully inserted, it is spraying the fuel directly on the lower wall of the neck of the tank. This causes a backup of the flow resulting in the handle shutting off as it is signaled that the fuel tank is full. When you pull it back out around 3 inches or so, the fuel will flow freely.

 

Thanks all.

I'll see what adjustments I can make at the next trip to the gas station.

I definitely do not want to spend $650 to fix a filter problem.... Can I do this myself?

Thank you all again!

 

Interesting you bring this up. I just had my 2015 in for service and this was one of my issues.
i have to fuel very slolwy or it will keep going off.

The dealership said there was nothing to fix and put a bulletin sheet in my car and some other material regarding thr fuel neck and the filler flap which i havent fully read.

It is interesting to hear about the charcoal filter being the cause. Unfortunate if it is not covered under extended warranty.

 

Have the same thing going on with my 2015. Dealer is saying it's from a cracked filler-neck and entire tank needs to be replaced. $5,400. How could the filler-neck be broken and there's not a trace of gasoline smell?

 

Time to go to a good Indy mechanic and see what workaround there may be. One thing about the stealership, they are only interested in the most expensive solution.

 

This has happened on multiple cars for me. I have noticed it happens a lot if I go to fill it up when the gas is quite low, there is lot of air which needs to escape. Need to keep a gap between the rubber housing and fuel hole to let the air out. It does mean I have to hold on to it but now I don't let it go low on all my cars. Would fill it up at around 25% and no issues. Gas station attendant confirmed this could be one of the reasons.

 

Good info, thanks for posting. I'm a habitual 'over-filler' on my other cars but for some reason have always stopped on the first click on the S550. Maybe just can't bear to see the dollar total on the pump go any higher ... LOL

 

​​​​​​... That's bull**** man.. Once I took my car in for a recall and they dint wanna do it said I needed to pay for diag time first and if I approved 150 dollars an hour for the diag I said fine but I won't get charged the diag time if you find the recall to be the problem? They said yes no charge and recall work will be done. I said fine. They called within 15 minutes said they will take care of the problem.. They called me like 4 hrs later said they did the recall work but now the car would not shift from drive & neutral and they had to replace the shifter assembly and it was gonna cost me 6k.. I was like wtf I took it in the car was fine now it's not and it was under your care you are responsible.. They said no sorry you gotta pay.. I said. **** all of you I want my car back as is. They said. Well won't go into reverse so we can't back it up.. I said. Okay the more reason you ****s shouldn't be working on my car anyway. We're is it? I'll pull the ***** out myself.. They gave me the keys said there it is have fun... So I went back there locked the steering one way out it in neutral 😑 pushed it back and drove the ***** home.... Soon as I got home I tore the damn car apart. Took the entire center console out to find the sum*****es had wedged a small folded piece of paper inside the interlock switch that you press when you need your car to shift out of park when you can't turn the car on. But by wedging it closed it locked the selector from being able to engage reverse and park seccessfully locking the trans in neutral & drive.. Also the key had to be left in the car because it doesn't let you take the key out of the ignition unless it's in park.. So they thought I would just fork up the money because it's aprety serious issue not being able to reverse or take the key out the ignition. They didn't expect me to be a no ****s given kind of person. . So yeah.. Idk but cracked filler neck sounds like another one of them situations.. Tell them to show you.. That you know they have a little snap on flex able camera that they can stick in the tank and show you the crack.... See if they can handle that ****..

 

There is a reason why sometimes you see "Do not top off" on the fuel cap of certain cars, I forgot if MB has it, the operator's manual might have it though. I used to top off to round the dollar amount to a number I like obviously wasting money and damaging the car in the processs, stopped doing that for a while now.

 

I don't believe this for a second lol

 

I sometimes have this too, depends on the pressure of the station. What works for me, is tilting/turning the handle towards the backside of the car.

 

I hope I am not being captain obvious, but part of filling a Mercedes with gas is knowing your car. Ideally you know the volume capacity of your gas tank in gallons or litres whatever the case may be. Then, with a little math, and estimating off of your fuel level display, estimate how much it will take to fill based on the current level. Not all gas gauges are super accurate, so it might take some time getting used to how your gas gauge works before you can be accurate with your estimates. With the Mercedes, in a lot of their models, they have the ecology tank, aka aforementioned charcoal canister. Its function is to accept any spillover from the main gas tank to avoid an ecological event, namely a fuel spill. So you want to take care to not overfill. You start tripping sensors, warnings, check engine lights, and maybe system suppression if you overfill. Once you get within a gallon(3-4 liters) of your estimate, hand pump the rest, AND STOP ON THE FIRST SHUTOFF CLICK.

 

I can testify to being stupid about this. I ruined 2 brand new cars by trying to get as much gas in the tank as possible. I was the guy who would hear it click/stop, then wait 5-10 seconds and go again until it stopped again, then waited another 5-10 seconds and put more in until it clicked off a third time. My only saving grace was thankfully they were both leased vehicles under warranty. A Jaguar XFR and Genesis 5.0 R-Spec Sedan. I still have to stop myself from going back after the first click. Not sure where I developed that bad habit, but my advice is to stop after the first click, just like w3hat MB2Timer says.

 

Well, you also waste some money over the years on that extra fuel being spent.