fuel tank rattling - PeachParts Mercedes-Benz Forum

adiaw83 · #1 05-29-2003, 08:44 PM

I think theres something lose in my feul tank. When my tank approaches empty, the rattling from the feul tank is a lot more apparent. The gauge does not work and has not been working for a while.

leathermang · #2 05-29-2003, 09:11 PM

If it makes more noise when getting towards empty... and your gauge is not working....then this is your car's way of trying to keep you from getting stranded out on the highway out of fuel.....It knows it might get hurt from some careless tow truck driver trying to get it home.... or that you might get struck by a careless motorist as you stand beside the car stroking the hand pump to get it reprimed....Not all cars are this considerate.. my VW used to let me get stranded on a regular basis... I think only expensive cars are trained in this manner....

rs899 · #3 05-30-2003, 06:42 AM

The rattle is caused by the aluminum tube that covers the float and wires of your sender. The nut securing the tube has worked its way off and the tube is banging around in there. I know this because I've got one like it in my 300D. I pulled the sender and only came out with the internal float mechanism and some tangled wires. I put a replacement sender in there but haven't been able to fish out the tube. I figure that when I get bored I'll pull the tank and flush out all the algae and crud and get rid of that tube.

Rick

adiaw83 · #4 05-30-2003, 05:06 PM

I've never done any work on the fuel system and am apprehensive to do any. How easy is it to get in there and remove the sender like you did. Also was your gauge out before you did this and did this fix the problem? How much did the new sender cost? thanks

rs899 · #5 05-31-2003, 06:07 AM

It isn't difficult. Not sure about a W126, but on a W123 remove the first aid kit and holder to get access to the float at the top of the tank. Unclip the wires, unscrew the large hex flange. If yours is cooperative you may be able to use channel locks. Mine was not and I had to borrow a friend's 1 13/16" socket . Pull up on the float assembly- it should take some time to drain- and remove. I am betting yours will come out "unsheathed " like mine and the aluminum tube that normally protects the float mechanism will be off and rolling around in the tank. My unit was not repairable because the fragile wires were ruined. I replaced it with one from a parts car so I'm not sure about the cost- I have heard it's ~$80. This would be a good/easy item to get at a upullit junkyard. Mine works now but I need to get in there someday and fish out that #&!@#% tube or drop the tank.

Rick

adiaw83 · #6 05-31-2003, 05:21 PM

sounds easy enough thanks for the info.