few suggestion
could you
1) directly power the fuel pump to run continuously
2) connect vacuum to the fuel line to suck out the fuel
3) fill the tank with diesel, vacuum it from fill hole, repeat 3-4 times

good luck

 

some more help

https://www.justanswer.com/mercedes/...erc-gl350.html

 

The tank is a saddle tank, so that's probably why you were only able to get some out via the filler... and the hose could have curled, as well. As far as using the pump... I would "assume" that the pump is only designed to run for a short period of time without the engine running... or, at least, that makes sense anyways.

Just throwing out an idea... Is there an access port(s) under the rear seat for the tank? For something like the fuel level senders? If so, access the tank via the inside of the car, remove the level senders and suck it directly from there.

As mentioned above, I would think "hot wiring" the pump should work as well. I would think you can do that via the fuel pump relay under the hood - but I wouldn't want to make a guess as to which pins you have to jump without researching it.

 

Generally, the access flange for the fuel pump/level sender/etc is accessed by removing the rear seat (s) and pulling the pump. Then a suction hose can be used to remove the contaminated fuel and you are sure it is all gone because you can see the bottom of the fuel tank. Its a big PITA but it is better than having to replace HPFP - injectors, etc.

 

 

 

Thanks to everyone for all the great ideas. I am an MB certified tech myself---I received my training in 1978-79 so as the years have gone by I find myself swamped by so many models that it takes multiple resources to get to the bottom of some issues. I run an independent shop and nearly all of my customers have had varying experiences with the local dealer that cause them to look elsewhere for their repairs. And the dealer shop foreman is a close friend who has been there for 45 years so he often helps me with problems since he has access to info that I do not. In this case the customer had his car towed to the dealer who quoted him $1,350 + for the repair and, worse, showed no interest whatsoever in doing the work. Customer called me and asked if I could do the work and maybe save some money, so the car was towed to my shop.
After some due diligence I was able to put together the scenario with this model which is:

• the fuel pump is a 4 speed unit and without the engine running, runs for 30 seconds and turns off
• the pump is located on the passenger side of the saddle tank and when it does not have fuel surrounding it, will not pump
• this means that if you pump all the fuel out of the passenger side, manually, you cannot get the pump to pump the fuel from the driver's side---Thank You Mercedes
• I manually sucked all of the fuel out of the passenger side and was left with 8+ gallons in the driver's side

Here is the procedure on this model to remedy the problem:

• After removing the fuel from the passengers side either by siphoning or running the pump (I used both methods successfully) go to the passenger side and lift up the rear seat
• After pulling up the carpet you will have remove 3 electronic boxes by unplugging and setting and setting them aside---various brackets will have to go also and then the wiring harness will need to pulled up and out of the way with a bungee cord
• At this point you remove a large rubberized disc covering a circular opening above the fuel level sender unit, that is NOT cut out or open!!! Thank You Mercedes
• Pick your tool of choice, either a drill bit and a nibbler, or a mini right angle die grinder with a cutting disc and very carefully cut out the disc and remove it---you must be very careful not to exceed a depth of more than 3/4" inch or you will either cut the fuel lines or damage the sender
• Once the cutout is removed you will have to either buy an $80 tool to remove the sender unit lock-ring nut OR you can very carefully cut the ring with a die grinder with a fluted carbide bit---the use of a bit is the fastest and least expensive
• Disconnect the two fuel lines to the sender---a special tool is required or you can "cheat" them off with some ingenuity. They are of the "push to clip" variety.
• You will have to buy a new plastic ring and rubber sealing gasket, but they are in stock and cheap at $39 (wholesale)
• You cannot easily remove the sending unit so merely lift it out and then suction out the remaining fuel. Once I did that I took clean rags and mopped the tank till it looked brand new and dry
• Fill the tank with10 gallons of diesel
• Reinstall the sender with the new ring
• Buy a tube of quick-dry body sealer from a body shop supply house. Use this sealer to put the disc back in place and seal it. Done correctly this will look OEM.
• Fill the main tank with another 10 gallons of diesel
• Car will start instantly and problem will go away

Since my labor rate is 1/2 of the dealer, I was able to save my customer $700 on the repair. I considered this work to be interesting and challenging but also quite a job. Not easy at all and there are a number of places along the way where one could make a serious error, so caution and care are required.
My dealer contact send me a page from the workshop manual that shows the procedure but is very sparse on instructions. I would not recommend this to be done by someone that does own not a complete set of shop tools along with an air compressor and etc. Also to note is that this is at least a 2 day job, even for the dealer.
Last I want to vent a rant at Mercedes:
After over 100 years of selling diesel passenger cars, Mercedes has FAILED to provide an intelligent, suitable means for draining gasoline from their cars. In fact they have assured GREAT difficulty with their over-engineered designs and show a clear disregard for their customers. With the advent of the CDI systems the contamination of fuel has become super-critical and gasoline sent into a CDI or later system will destroy very expensive components quickly. The dealer told me that if the customer starts their car with gas, the repair cost is $12,000 on this model. Not funny, Mercedes.
Also to note---in England their is a 24 service that will come directly to the service station where you wrongly pumped gas into a diesel car, and will pump out all the gas while you wait. They have a guaranteed arrival time of 45 minutes and a minimum charge of $125. I doubt they are successful with saddle tanks, but they state that someone in England pumps gas into their diesel car once every 3 minutes. So Mercedes KNOWS this yet they still do nothing to assist.
Photos attached.