W202 fuel gauge problem !!!

[mjcr666]

Ive aquired a new car, a 1996 c220 elegance and it is absolutely mint and drives like new.....but the fuel gauge seems to have a mind of its own, when i put say £20's worth of fuel in it, it will show me the amount i have put in but after driving around the fuel gauge will tell me its full then half full then empty and will carry on doing this until i stop at traffic lights or in traffic and then it will show me the right amount thats in the tank.......now is this a problem with the speedo or the tank ???

please help me if you can


mike

 

[Spinal]

This is actually quite a common fault with W202s; it's the sensors/senders in the tank.

There are two of them, and they tend to get gunked up.

Some people have reported good results with changing fuel brand (none of that supermarket gunk), while others seem to have managed to squeeze some life out of them using fuel-cleaner additive.

Personally, I found that refuelling in Morocco and Southern Spain seemed to get them working, and the moment I got back here, they stopped again.

In a nutshell, the only surefire way of getting them working is replacing the 2 sensors in the tank.

M.

 

[mjcr666]

To be fair i had a feeling it was a sensor, it does makes sense that it is the sensor seeing as the gauge does work from time to time, its almost like the gauge is measuring the fuel's every move lol
ill get my mechanic to have a gander tomorrow then and see if he can do it for me !

thankyou for helping with my small problem.

mike

 

[andy27168]

Hi,
I have had similar issues on my 96 build C230K, it always seems to correspond with using unleaded or supermarket fuel, i think you,ll find your car should run on super plus like mine, a couple of tanks of the correct or good branded fuel always sorts my gauge out.
You could try a good quality fuel additive as i believe this will also sort it but i can,t talk from experience on this.

 

[Spinal]

It's actually something you can do yourself if you can sneak under the car... just make sure you don't have a full tank of fuel

I would reccomend Pit Start if you're around London - for £20 you can get your car on a ramp and fiddle under it

M.

 

[alibally]

The sensors where modified from single contact sensors to gold plated 3 finger contacts to help stop problems from bad connections due to all the addiitives in modern fuel. They are better to be changed in pairs There is a tool for removing the ring for holding them in the tank. Due to the position of them they can get corroded in as the securing rings are alloy and the threads are steel on the tank. I have had to cut the rings out before as heating them really is not an option.

 

[vijilants]

Please note, if you are doing this you must also have access to a compressed air line in order to blow out the interconnect pipe between the two sections of the tank.

It is very important that you do this at the same time as replacing the senders.

 

[DITTRICH]

My fuel sensor "cure" was simply to start putting more expensive fuel in for a few tanks rather than the supermarket stuff which I normally use. On the two occasions this has happened in 10 years of owning the same w202 this cured it both times. Note - a few tanks of slightly more expensive fuel will be less than the hassle and inconvenience of replacing the sensors.
My 2c
Les

 

[horatio]

Digging up an oldun here.

Is changing the sensor a job for a specialist or can this be done DIY with a Haynes book of lies? I can't seem to find a guide for doing this job on the net.

Does the tank need to be removed?

I would have access to a ramp.

thanks