thelearner

Looking at a 2008 E63 as CPO and the carfax states that the fuel level sending unit was replaced 5k miles before. The car has about 49k miles and otherwise looks decent. Should I treat that as a red flag or don't worry about it?

black06c230

I wouldn't worry but I also don't fill up all the way which is what i feel contributes some to this issue. Still a flaw of some sort but a good way to help ensure fewer issues.

novae500

by having it done already, saved you around $900 for another 30-40k miles.

TheOtherDodge

For what its worth, mine is being replaced as we speak under warrenty.

Why does filling it up all the way contribute to the failure? I ask because I fill mine up..

black06c230

if it's full then the gas is closer to the top and therefore can more likely leak out from that area.

TheOtherDodge

How does that promote the failure of the sending unit?

novae500

There are several posts about the gas leak due to poor design of the fuel system of e class cars

TheOtherDodge

Thanks novae500 but this post is about the sending unit and that is what I am asking about. I was quoted by black06 and he said that filling it "up all the way which is what i feel contributes some to this issue". So I would like to know how filling the tank all the way up contributes to the failure of the sending unit.

novae500

The sending unit and the gasket are part of the problem. Over time there are theories that the gas is eating the gasket and letting gas seep and pool on top of the sending unit.'those who do not want to fix fill up less than half a tank. Both my w211 had to have fuel sendinninots replaced due to seepage pooling.

black06c230

Exactly so that is why I don't fill up all the way, 3/4 yes, but why keep filling up all the way it the gas could be causing the issues because the seals are bad.

Why pay $900+ to fix an issue just so you can fill up again and again and have the issue occur again and again??? Doesn't make sense to me.

Should MB find a true fix yes, but until they man up or the NHTSB makes them why deal with the hassle and headache. Stopping for gas is normal in these cars what's a few more stops??

Just my opinion, and I don't have a leak issue.

novae500

Yep. Couldn't agree more. I think it's the ethanol that's eating the seals prematurely

black06c230

i could certainly see that at it would of been designed around the time ethanol was just being mixed with the gas.

thelearner

Well this escalated quickly...lol

After my initial talks with them the dealer has gone MIA. Not sure what's up but o well.

With the 2014s coming out soon maybe I should hold off until then. Also not sure what to make with the 2009 prices as they don't seem to be steady across the market. Found some for $50k and others for around $45k with the same number of miles and options.