All of a sudden my 99 E300 DT is spitting diesel. I read some earkier posts and replaced the fuel tank cap but it is still burping diesel. I assume that the fuel tank vent is clogged but have read differing suggestions on its location and how to clear it. Can anyone offer me assistance on where the vent is located on a w210 and how best to clear it.

 

Well I visually checked the fuel vent and did not see any obstructions. Any suggestions or what to do next?

New fuel tank cap done

Fuel tank vent no apparent obstructions

Next???:o

 

Where exactly is the diesel leaking from? Do you have an exact location? Can you idle your car or rev it's engine in the drive and see any fuel drip? Maybe it's your fuel filter connections? Has it been serviced recently or at all? Also, can you smell any diesel when your engine isn't running from any particular spot?

 

Diesel is coming directly out the fuel tank filler. Backside of the fuel cap is soaked with diesel. If it does not spill down the side, it leaks down the overflow next to the fuel cap and drips behind the right rear tire.

When I get another daylight opportunity, I am going to blow some compressed air up the fuel tank vent which is centered above the rear axle next to the fuel line from the tank.

 

Odd considering it's a new filler cap! I can't imagine why it's leaking?

 

I'm having the same problem. Any known solution?

 

as far as I know no vent in those tanks bcs envirromentally unsafe any way I will call my mb service and ask

 

I am going to a local independent service center tommorrow. I will let you know. BYT, there is a vent that exits near the rear differential.

 

Put your seatbelt on! First, my indys are certified MB mechanics so they know their stuff. We checked the vents last week (they were clear) and put on a new gas cap. It held for a bit, but as soon as I put in more fuel (half tank) it was leaking again. Not as bad as before, but leaking. I went back to the shop this morning. They researched the issue today; called me back this afternoon; and are telling me the only solution is a new gas tank. The tank is one unit and it's around $700 new. I thought about used, but a tank that's just been sitting around likely has a bunch of crud in it and by the time you go through all of that, it probably won't be worth the initial savings.

If you find out anthing different, please let me know ASAP.

Some days you get the bear; some days the bear gets you.

 

Apparently the fuel filler neck was bent, but could be straightened. Tested okay but tank was not full. Next step is a new fuel tank. Will see how logn this lasts, but am back on the road.

Biobenz, if your mechanic is unable or unwilling to try and straighten you fuel filler neck, then it is reasonable to replace the tank.

I thought I was being careful when fueling, but apparently not careful enough.

 

I had to spring for new fuel tank (a grand installed - ouch!) I just purchased this car, the P.O. was aware of the issue and that the car potentially needed a new tank and that was part of the negotiation so the $$ bite was not as bad as it could have been. New tank and cap, no leaks. Close inspection of the old tank, once it was out, shows the filler neck had become slightly oblong from 6:00 to 12:00, with the our of round being a bit more pronounced at 6:00. In short, 84K miles worth of shoving a fuel hose handle into the fuel tank neck had take its toll. The message here is be gentle when you are filling your fuel tank.