Max.H

Got a faint fuel smell at fill up and the gas cap warning lights up red along with the fuel light that blinks.

Some questions:

1. Could this cause a lean condition at WOT? With fuel leaking, wouldn't the drop in pressure cause any engine related issues?

2. Last I checked and the passenger side had the fuel puddling. Do I just replace the fuel filter sender assembly and call it a day?

3. What about the blinking fuel light and gas cap warning display? Will that go away after the fuel sender replacement and a battery reset?


Also any suggestions or helpful links regarding the blinking light fix would be a great help! Thanks.

tolentino71

Replace the entire fuel sending unit, and replace the gas cap just to be on the safe side. I hope all goes well. Keep us posted on your progress. Good luck!

Max.H

Thanks!

I thought the blinking light is the evap sensor? What do I need to do to get that to turn off?

Anyone?

Can Drive 55

I had the same problem last year and it was the evap sensor or the valve. The dealership fixed it for just under a million dollars. Or so it seemed. There were several other things done at the same time, so I can't say what the exact cost was, but it was pricey.

Max.H

Jeezus… Well, Thank You I appreciate your feedback. I plan on fixing this myself. So, I need some vital info.

211.070

The fuel tank pressure sensor is mounted on the fuel filter assembly. These units usually leak in the area just below the pressure sensor. The filter housings are notorious for cracking. Depending upon the severity of the leak you have. It could cause your blinking light. Diagnose, and fix the fuel leak first though!

Max.H

I can only find the fuel pump assembly for sale. How much does a new filter assembly run and where is the best place to get it. Would you know? Thanks

E55AMGGG04

I had the same problem from about a month. I bought some techtron stuff and poured it in my gas tank. I did this twice and I havn't seen the message for a while. Before u go ahead and do something that costs $ try this out.

211.070

I think the fuel filter assembly(211 470 5094) costs around $350-450. The seals(211 471 0579) for the sending units are ~$20 each. You can get the parts from the dealership.

It would be best to properly diagnose where the fuel is leaking from.

1) Remove the rear seat bottom

2) Remove the access panels for the fuel sending units.

3) Clean the area completely of any fuel, dirt, and debris.

4) Either fill the fuel tank full and see where the fuel is leaking from. The other option is to pressurize the system with a smoke machine, or regulated air through evap line under the hood.(at the purge valve) Spray the filter housing/fuel tank with soapy water and watch for bubbles.

Can Drive 55

If it helps, here is what the tech wrote. "Necessary to R&R right rear wheel, R&R right rear wheel liner and remove and replace canister shut off valve to correct." So, it looks like it is located near the gas tank on the passenger side. The dealer charged $256.50 for the valve (part number 000-470-71-93), $25.50 for electrical W (211-440-03-34) (whatever that is), $6.09 for seal ring (029-997-84-48), and $229.12 labor.

Max.H

Thank You, Ive done the initial check and it is leaking but just barely around the top of the fuel filter assembly on the passenger side only. Driver side where the pumps are located are nice and dry.

As recommended by shardul I will swap the green $20 gaskets and see if that takes care of it. Its not pouring out, just barely pudding when i fill the tank just on the passenger side.

Max.H

Thank You for the help!

Interesting… Canister shut off valve… Hmmm wonder if that is what closes the tank when its full? No idea,

Anyone know what that is??

211.070

This is the charcoal canister shut off valve, adapter harness, and seal ring. This is part of the evaporative emissions system. As pressure builds in the fuel tank they need to escape. The activated charcoal canister aids in the absorption of this. The shut off valve opens for (safe) out gassing of the otherwise sealed fuel system.

Can Drive 55

My original symptoms were a red fuel cap warning and a blinking fuel light. When I called the dealer, the customer service rep said that it could be a bad fuel cap or maybe a loose cap. she said to remove it and replace it and see if the warning went away after a few miles. I did that several times over a month or so. The warning went away for a while but it came back repeatedly. There was no fuel smell associated with the warnings. When the light came on, I would shut off the engine and remove and replace the fuel cap. The light went off and not come back on for a few days. I was not very concerned because there was no gas smell, nor did it cause any performance problems. When I took it in for the next service, the tech told me the warning light came on when the sensor did not detect vapors when the valve was supposed to open. I am quite sure my problem did not have anything to do with the fuel sending unit. That failed one day and the engine shut off instantly. Fortunately it was in warranty at the time. That was a very expensive repair that was on MB's dime.

Good luck with your's. Let us know what it is when you finally figure it out.

Can Drive 55

I think that all this valve does is open to purge vapors from the tank/system and filter them in the canister. I don't think it does anything during refueling. I am not a tech, so what I am saying is not necessarily fact, it is what I believe the tech said when I took the car in last year.

Max.H

Will do… Thats exactly what my car does once in awhile. But, it doesn't do it all the time its very intermittent. Only sometimes and I can't really replicate it. When I turn off the car and check gas cap light goes away and doesn't come back on for awhile. It's not a huge deal but I will address it because I like to keep my cars in the best condition.

Can Drive 55

Your symptoms are just like mine were. I didn't worry about it either. Just waited until the next service. Just like you, I keep everything fixed when problems occur. It has 94K on it and it is almost like new inside and out and runs like it did the day I bought it. It's been driven very conservatively. Still has the original pads and rotors and there is a lot of life left in them. Certainly in better shape than it is worth in dollars. I would let it go if it had not depreciated so much over the 8.5 years I have had it. That is the price one pays for buying a new AMG, especially one with so many options (everything but pano roof). Glad I did it, but I doubt if I would do it again. Think I will drive it for a couple more years and see what happens. I am sure your will be easy to fix and will be just fine when you get it done.

Max.H

Wow thats awesome man. I hear what you're saying as a used car buyer you get a hell of a lot buying these cars. But, as a seller you most definitely will take a loss. Strange thing is I don't see that many of them for sale as I did in the last few years. There used to be a lot on ebay now there is none last I checked.