Fuel filling issues
The only thing I can determine is that most of the stations are Sunoco. I should preface that by saying that I nearly always use Sunoco because of the gas discount promotion Price Chopper is running. For those that don't know, every $50 in groceries at PC = a dime off per gallon up to 20 gallons. I got 20 cents off per gallon today, but worked hard to get my discount.
I'm going to take it to the dealer tomorrow after work to see what they say.
The suspicion is the nozzles at some of these pumps are about 1/4" too short, so the fuel splashes around the fill area by the nozzle and triggers the shut off.
Some have had success with a new air bypass tube, but it is not a 100% fix.
My guess is that whoever is engineering these tank fill inlets didn't do all their homework or thorough field testing before they sold them to manufactures.
The fuel station at Ramstein Air Base Germany said that the pumps are set to shut off with very little back pressure, As the EPA wants to prevent fuel spillage. And that they have had a lot of complaints about the pump handles clicking off. So I think that is the main culprit. At the off post European stations, I've never had an issue.
My Caterham has a very short filler neck (6-7 inches) and is very large (2-3 inches) and has no breather tube.
Last edited by super7pilot; Jul 21, 2014 at 02:10 PM.
No such problems in Washington, which have basically no advanced vapor guards.
Last edited by mjhawkins2346; Aug 8, 2014 at 09:05 PM. Reason: spelling
The Best of Mercedes & AMG
I find it hard to fathom that it works fine with all other cars and only messes up with mercedes. shouldnt there be a big uproar related to this. ?
I mean a car like mercedes and we cant fill gas in it?

at least here in california it's a mix of the mercedes fuel opening and the healy vapor nozzle and it has nothing to do with overflow.
i hv said it here or in some other thread, but i took my friends (non mercedes) car to the same pump where i had issues and found out that the nozzles goes in a lot deeper in his car than my c250. as a result of it going deeper in, the rubberized cover on the top of the nozzle covers the opening and doesn't allow any vapor to escape.
in my c250, it stays on the periphery and hence cuts off the pump when it senses the escape.
tilting the nozzle at an angle, and pressing it in solves the issue sometimes.
i spoke with my dealer and he said he has heard about this problem from multiple ppl and its the nozzle that is faulty.
i emailed mercedes customer service as well and got a call back from them saying they can't do anything about it.
it is unacceptable that they refuse to accept that its their fault. this almost calls for a class action lawsuit.
*ok i am being over the top here* but still :P
if all other makes work fine at gas stations and mercedes has an issue, then i am sorry to say but its not the nozzle's fault.

at least here in california it's a mix of the mercedes fuel opening and the healy vapor nozzle and it has nothing to do with overflow.
i hv said it here or in some other thread, but i took my friends (non mercedes) car to the same pump where i had issues and found out that the nozzles goes in a lot deeper in his car than my c250. as a result of it going deeper in, the rubberized cover on the top of the nozzle covers the opening and doesn't allow any vapor to escape.
in my c250, it stays on the periphery and hence cuts off the pump when it senses the escape.
tilting the nozzle at an angle, and pressing it in solves the issue sometimes.
i spoke with my dealer and he said he has heard about this problem from multiple ppl and its the nozzle that is faulty.
i emailed mercedes customer service as well and got a call back from them saying they can't do anything about it.
it is unacceptable that they refuse to accept that its their fault. this almost calls for a class action lawsuit.
*ok i am being over the top here* but still :P
if all other makes work fine at gas stations and mercedes has an issue, then i am sorry to say but its not the nozzle's fault.
I have had no experience with filling in California as I have never filled up there. I have filled up in Idaho, Oregon & BC, Canada & have not had any issues, Not one. So clearly it is an issue with the government of California mandating that stations collect the vapor from filling up. Like most things the government does. They threw a wet blanket over the whole thing and just sits back and does nothing to rectify the mess they made.
Perhaps it would be more appropriate to sue Gov. Brown and have the vacuum vapor nozzles removed.
And I'm sure you are right that the issue is the healy vapor recovery system. The issue at hand with those types of pump nozzles is that if there is a restriction (a fault) in the pumps vapor capture system. I.E. Not pulling enough air from the tank and thus restricting the tanks ability to make room for fuel. It will create too high a pressure and shut of the fuel flow. So tell me then. how is it a problem that MB is supposed to solve? Is MB supposed to redesign their fuel tanks because of ONE nutty state?
I have had no experience with filling in California as I have never filled up there. I have filled up in Idaho, Oregon & BC, Canada & have not had any issues, Not one. So clearly it is an issue with the government of California mandating that stations collect the vapor from filling up. Like most things the government does. They threw a wet blanket over the whole thing and just sits back and does nothing to rectify the mess they made.
Perhaps it would be more appropriate to sue Gov. Brown and have the vacuum vapor nozzles removed.
And I'm sure you are right that the issue is the healy vapor recovery system. The issue at hand with those types of pump nozzles is that if there is a restriction (a fault) in the pumps vapor capture system. I.E. Not pulling enough air from the tank and thus restricting the tanks ability to make room for fuel. It will create too high a pressure and shut of the fuel flow. So tell me then. how is it a problem that MB is supposed to solve? Is MB supposed to redesign their fuel tanks because of ONE nutty state?
i would say yes, if all other cars work fine at those stations and only MB doesn't.
i have friends driving
audi, bmw, infiniti, toyota, honda, hyundai, mitsubishi to name a few and only MB has this problem with multiple pumps in this area.
as i explained before, its a question of the outside edges of the fuel tank opening to be big enough for the haley pumps to be inserted properly and the problem is solved.
only the MB one has a lil smaller radius which prevents it from happening. all other cars work fine.
yes, i can blame the govt for mandating the use of these pumps and it didn't work with 90% of the cars and only worked with 10%. in this case, it works with almost all except MB. so sorry but MB is at fault here.
But I do have a small problem opening the filler flap! Maybe I should read the manual, but pushing on it doesn't release it. I have to try and get my finger nails under the edge to get to open

admittedly
Push the nozzle all the way in until the spring in the hood is fully compressed. Then turn the nozzle clockwise to the 8:00 position - about 45 degrees to the left.
I have found it might click off once when I'm totally empty but even that is rare.
I can usually fill at full flow rates now without false click offs.
All the nozzles I've used are Healy nozzles.
He tried bypassing the charcoal canister (as recommended by many) and checking all the lines to make sure they were clear and still no luck. It got to the point where the care was almost useless.
This problem existed, but got worse after the dealer removed the engine for a major repair. The repair sidelined the car for a few weeks, and when he got it back the filling problem was extreme.
The solution: replacing the bypass valve unit near the charcoal canister. This valve is energized (closed) when the car is running and opens when the car is off for filling.
The problem is that the rubber seat in this valve assembling becomes sticky and does NOT open up as it should to allow venting when its solenoid is not energized. (I guess the stickiness of the seat is too much to be overcome by a spring or the force of the solenoid.) The stickiness was tolerable until the car sidelined for a bit, then I guess it was stuck in the closed position due to lack of force from the open solenoid and degradation of the rubber surface providing the vapor seal. It seemed poor, but usable as long as it was being exercised. Once the car sat for a while the adhesion was just too much and it would rarely open to permit proper venting.
Many of the articles about this problem blame it on the US$500 charcoal canister being fuel soaked from top-offs, and and recommend bypass or replacement. Similar articles talk about cleaning or removing the filter media that is part of this electric vent valve. In his case, undoing the recommended bypass of the canister (returning it to factory setup) and installing a new valve solved his headache.
One last annoyance is that the valve assembly is made with either a straight or 90 degree port and the VIN number won't tell you which one you need. Sadly, you have to remove the fender lining to see what you have so you know what to order. In the end, a $150 valve unit solved the problem and he can now sit in his car while the pump fills at full speed.
Hope this helps others.
Last edited by Eric Halpern; Feb 9, 2019 at 05:49 AM.
The fuel filler neck in my c207 (2010 e550 coupe) has a whole about 2 by 3 inchs. So when i fill up fuel with the nozzle all the way down it leaks, but when pumping slowly i can get most of it in, aboout 95%.
The only place to find a fuel filler neck is at the dealership and they only sell the entire gas tank for over 2K. I did my research and no one sells the hose, unless its a DIY.
My idea was to get about 2 ft of hose from the local parts shop, cut it down the middle, wrap it around the hose, and clamp it. This will tighten it, but a sealent should still be used around the edges of the new hose overlapping the old one to assure no air is going through. I have a gasoline proof product i had in mind to use.
Am i crazy for trying this? any other ideas? A new gas tank with the labour would cost right around 3500. Requires to droo sub frame to get to it.








