kicker

Hi,
My fuel gauge reads almost above 3/4 tank when full, I cannot even top off, tried few gas station still does the same thing. Does that means my fuel tank sending unit is broken? how to replace that? I've been searching on the fourm, no directions found. This is all happens after the dealer replaced my MAF sensor, just right after my warranty expired. what a timing. I end up paying $306 for the labor just for the MAF, dealer is kind enough to replace the part for free. Go figure on their labors!!! please read this thread https://mbworld.org/forums/e-class-w210/79413-check-engine-light.html
it will tell you guys more about it.

anyway I called the dealer back, they want me to watch it for couple of weeks, see if the gauge would come back. another question is when replacing MAF sensor could cost this gauge to fail also?? I don't think so right?
any help is greatly apperciated. I have E320 MY2000

saturnstyl

No replacing the MAF has absolutely nothing to do with the fuel level sending unit. You got a banner year for needing a new one, and its not hard to change at all. Takes about 5 minutes, a labor charge of one hour including diagnostic would be acceptable to me. If they wanna play hard ball just tell them to change the darn thing and don't pay diagnostic. They go out of range fairly often and on several models. Yours is one of the easiest to change. If you have a LARGE pair of channel lock pliers you could do it yourself, its virtually fool proof. Located at the very front of the truck, more towards the passenger side. Pull down the lining at the very front of the trunk starting at the upper right corner until the sending unit is exposed. 2 connectors, twist out, twist new unit in, make sure its seated, and reassemble.

kicker

So sending unit connector is at outside of the tank? I don't need to empty the gasoline tank and replace the flow meter inside? Because when I replace my shocks last time, I did pull the liner off and saw the gas tank. If it just a twist off and twist on, and No fuel exposed? Can you be a little bit more specific? How much would the sending unit cost? thanks for your help!

saturnstyl

The sender is in the top of the tank, so removing it shouldn't cause any fuel to spill out. As for cost, I don't know but they aren't very expensive.

saturnstyl

No fuel flows through this sender either. All it does is measure fuel level in the tank. It also has a pressure sensor in it. No line connections or anything, like I said, twist out, remove, reinstall. Its very simple.

kicker

thanks, will wait for fuel real low and fill it back again, if it doesn't work, will order a new part. I checked fuel sending unit is around $170 now.

another question, I top- off the fuel few times about 3 days ago (since the gauge wasn't functioning correctly), I smell some gas fumes around engine compartment yesterday, like when you stand by your front fender while engine is running. But today I didn't smell anything. I heard if top off the fuel too many times, it will cost fuel ran back into the charcol air filter? I hope it didn't cost any damage.

saturnstyl

If you overstuff the tank the canister will fill with raw fuel. It becomes a real problem with the purge solenoid, because when it activates the liquid fuel is sucked down the intake which results in a very poorly running engine at best and most likely it will just stall out. Some people elect to replace the canister, others just drive it till it gets all sucked outta there. I wouldn't worry about it as long as its running okay.

kicker

thanks for your help, I'll watch out more next time. I hope everything will be allright. Cannot believe when the warranty just out, everything just went wrong!!

RJC

Florida and other states had problems with Shell gas causing this within recent months.

saturnstyl

We were sent a memo regarding the excessive sulfur content in some of their gasoline. It was eating the silver printed circuit off the sending units if I remember correctly.
The catch is that it was only the regular grade of fuel, which in a nutshell means only regular and midgrade were affected by this. Since we all have to run premium fuel in our benzes, we shouldn't have been affected by this thing at all!
Again, you got a banner year for failures of this part. I have replaced many of them.

kicker

Say if your charcoal canister got soaked with gasoline, is it hard to replace them? or would they enventually will evaporated out?

saturnstyl

Well I don't KNOW the answer. I guess you could remove it and dump it out and hope for the best.... They aren't usually too difficult to get at, but they are all located in different places.

wizkid

I am about to replace the fuel sending units on my C240. I have two of them. Maybe they are as easy to replace as yours.

Keep us posted on your progress. I plan on putting a a step by step install guide with photo's of the procedure to help others.

We only use 93 octane gas and our sensor has been out for some time now.

Eric

mleskovar

"I plan on putting a a step by step install guide with photo's of the procedure to help others." This would be great to see/have...please do!

wizkid

Please see my other post. or just check out www.installuniversity.com

Kicker, if you decide to replace the unit, can you at least take pictures of each step. I will write it up with your help if you can supply pictures.

We need to start documenting these isntall's to help everyone that wants to do the job themselves.

Eric
www.installuniversity.com - The MB Installation Site

kicker

well do, will take pictures if I decide to replace them. Is C-class got the same unit and location as E-class?

wizkid

I have no idea but they can't be too different, I would think. I know my C class has two of them. One on each side of the tank. You may just have one since you have more room under the larger car. If so, lucky you!

Please let us know how this goes. I hope you end up replacing it yourself.

Eric Barger
www.installuniversity.com

wizkid

We use Shell gas about 99% of the time. Always 93 octane. The car has never seen anything below 93. After about 75k miles on it, we noticed the problem with gauge.

Eric

wizkid

Have an update?

kicker

it started working after a while...got fixed by itself, so I haven't replace it yet.