Neanicu888

Hey guys!

As always I appreciate your input before I move to the next step.
My tank was about a quarter full yesterday,so I've decided to fill it up. After filling it up the indicator was showing me Full like it should.
Today,driving to work,I've noticed it started going down pretty fast,it went down a quarter of a tank from Full after doing 10 miles. Now that's ridiculous, I know these cars are not that great with gas,but. 'Come on!'....
After 2 hours I started it again and now it's showing me a quarter of a tank full when I know the tank it's Full because I only did 15 miles since filling it up.
My question : is it the fuel level sending unit located in the tank? Is there any test I can do to make sure it's that?
I had another car with a bad fuel level sender and that one was showing me that the tank is completely empty, the needle didn't move at all,this one it's showing me a quarter full.
Thanks.

C43AMG

Common problem with the W210 & W202's.Yes the problem is in the tank.

Neanicu888

Thanks C43AMG!

Is it hard to change?
Can I do it myself?
Is it behind the backseat?

Neanicu888

I just spoke with a mechanic I trust over the phone. He told me not to buy the fuel level sending unit until he takes a look at it. He said that sometimes it's not necessary the fuel level sending unit the problem,but the actual cluster.
Now I'm confused ....

theunderlord

Check this for more info?

Neanicu888

That has nothing to do with my car. Those are W211's AMG.

Fabio D

The problem is not the cluster, is the sender unit.. Remove the back trunk carpet, you would see the inox tank and a little white plastic with a connector. is this the sender unit. With 1/4 turn it pop out. Change it yourself and you solve the problem

Fabio Daniel

Neanicu888

Thanks Fabio D!
I will do that!
I was thinking to change the gasket too. Do you know if the gasket comes with the new fuel sender unit or you have to buy it separately? I see it sells for 10$.

Fabio D

I think it's included with the new sender unit my friend anyway is not really necessary to replace the gasket, i clean my sender unit some months ago (with no positive results) and the gasket works perfect, use some vaseline on it when install again and all works good

Fabio Daniel

Neanicu888

I just got the fuel level sending unit in the mail.
It's OEM....VDO.
Here are some pictures :

Billvich

Please let me know if it works and how much it costs,
My 2002 ml55amg does the same thing?

Neanicu888

I'll probably change it this weekend and see what happens.
My unit was 140$,but I don't know about your car,because on some newer models they've put 2 units.

Fabio D

Nope, bro, u'r ml55 level sender comes with the ful pump as well. you need to remove the rear seats, carpet and you would see under the carpet a roud cap glued with some silicone, remove this cap and you would see the tank with the pump. but is not easy to change it. i reccomend you a indy shop to this job... the W210 sender unit is pretty easy to replace, but your W163 is pretty hard

Hope this help

Fabio Daniel

mbmoding

Why would the sending unit be hard to replace? It isn't because of removing the rear seats and pulling the carpet back it is it? because that isn't hard to do. Now if you had to drop the gas tank, that you would just have to wait till you are low on gas so it's easier on the load.

Fabio D

Remove the rear seats in the ML model is a pain! have lots of screws, you need to remove some plastic panels with meticulous careful to not broke the hangers and the seats are so heavy, after, you need to pull the carpet in the driver side and cut some silicone glued metal cap to see the tank cap

Fabio Daniel

mbmoding

Yesterday I just replaced the entire unit. It was actually not bad and the job took me about half an hour to do. I've removed the plastic parts and bolts before so it was easy for me. You don't need to remove the seats, just move them forward so no weight to really deal with. Evidently when I got to the cap area, I noticed it was opened and serviced before. I replaced the unit anyway and afterwards tested the old unit and it seemed to be working correctly as I've metered it and it had no glitches. I'm concerned now after reading more on this forum. The gauge is working fine now but I think only because there is not a full tank of gas but more like 3/4. I think once the gas gets near empty and I fill it up, I will still see the same issue. I hope not but it looks more likely since I found no issues with the one I replaced with. I called the dealer but with no surprise, I heard the typical BS I've been hearing. They say these words assuming you're not experienced about anything technical. While I may not be an MB tech., I am in the automotive industry working with electronics and custom installations.

They could not even tell me the simple common problems, common, you hear more feedback in the forums, how can a dealer who has been fixing thousands of the same car not able to tell me the most common problem of the typical issue, I don't buy that and I told the service adviser that. He was silent, go figure. Their objective is to try to get you to come over and spend money, (more than you really need to) than to truly help you out. I know the industry is very tight and you can always tell by how the service adviser speaks to you. An independent is the best way to go as long you find a trustful reputable one. I've so far done all of my service on all my cars. Never had any mechanical issues besides wear and tear.

Out of all the common issues with these ML's I think the fuel gauge issue is the biggest one. I've dealt with the motor mount issue and done the replacement myself along with all the fluid and filter changes. All seem no problem to deal with since parts are not that expensive. The fuel sender / pump was the most expense I've had so far out of everything I have dealt with on this car and it seems to be the most common ongoing lifelong issue? Other than that, my car drives like a champ. This is my second ML55, my first 55 had no major issues besides the typical sunroof air dam flying off and the glove box hinge falling off. (I've modified and fixed that issue permanently) I also forgot to mention the electric climate control water pump, that is another issue to. I may make my own modification as the OEM one has issues with the armature failing or the entire inside corroding due to bad seal. I am thinking about putting a different motor assembly. I will talk about it on a topic regarding that issue.

Bob

Neanicu888

No,it is not a common issue just with Mercedes,fuel level sending units go bad on all make and models at some point,they sit in gas all their life...
I don't see how you've tested the old unit...you can't really tell when these are bad,except that they're not showing the proper fuel level. They might seem ok and sometimes cleaning them might even make them work again but not for long. They have some contacts on them that you really can't tell or do much about.
Don't worry,if you've installed a new unit,it will work. Just fill up your tank with confidence! Unless your cluster is bad,which I doubt...

mbmoding

Well after replacing the entire unit and it's about 2 months now, it is working out good. We'll see how long it will last. I have heard also if you run your tank till it's near empty as a habit and that because the metering part is not soaked in the fuel, it gets dry and warm so they go bad sooner. Not sure if that is the case but I will be filling at about half tank from now on.