Fuel Gauge failure

[cian36n]

Today after I filled up, I noticed that my fuel gauge just quit working and the reserve light would stay on for a little while as well. I noticed it right after I got on the road and after I reset my tripodometer while driving, so I dont know whats going on. Any ideas?
Thanks,

Ian

[kameraguy]

How long have you had your car btw? Is this the first time you noticed it?

A lot of us have the exact issue you do. If it really is the same issue, then give it time....the guage will work normally after a while.

Some theories range from a typical symptom when the tank is filled to past maximum.

Others state a possible vacuum leak may exist. Double check the fuel cap surround for wear. if in doubt, try a replacement cap as they aren't too expensive.

I beleive there's a tool to check for a vacuum leak in the engine bay, between the airbox and the first MAS. Might wanna ask a mechanic about that.

If it's a sensor issue, you should see a trouble code in your computer. Check the DTCs. If it's a sensor, there are two fuel sensors that can be at fault. It sucks because apparently it costs around $700+ to fix either due to labour.

It seems this is not 202-specific either. On Mercedesshop a lot of 124 owners post similar issues.

As long as it's just an intermittent guage issue, just use trip odometer religiously. And consider this one of the minor "gremlins" of the w202 :(

[Tom Q]

mine does this too. The gauge stays on E and low fuel light is on. This usually happens after a fill-up or a car wash. It's been months now since this last happened though. I just hope it doesn't happen again. :)

[steponit]

yeah i have had the same problem for the past couple of weeks. ive read that it may because of the effect of heat. it has been hot lately here in the bay so im just guessing thats my problem.

*will a vaccum leak be a serious problem.. or just something that messes up the gauges?*

[jnolte]

hit the damn dash

[manny]

Here is the real scoop on this issue.
I just had both of my sending units replaced by the dealer ( luckily under warranty ).
The fuel composition in North America does not " agree " with the original senders.
GM has had a ton of problems for the same reason.
The new sending units have gold-plated contacts, which are not affected by our lousy fuel.
You could try to run a few " double doses " of strong fuel system cleaner with your next few fill-ups, it may help, but don't expect miracles. i;)

[kameraguy]

manny, did they say how much this cost btw?

damn those stupid sensors...

[manny]

Originally posted by kameraguy
manny, did they say how much this cost btw?
damn those stupid sensors...

They didn't say how much it would have cost, and I sure didn't want to ask.
You can lay the blame for this annoyance on the sh...t fuel we have. ;)

[cian36n]

Kamera,
I have had my car since October of last year. When I got it it had 62,000 miles on it and it now has 67,000. This is the first time that I noticed it, and I hope it is the last time that it ever comes up. It could quite possibly be that I over filled it, as I noticed that the gauge wasnt working after about 30 seconds of filling my car.

I checked the seal around my filler cap, and it looks fine to me. So I dont think that is a problem.

Speaking on the vacuum leak problem, I'll talk to my brother about that and see what we can find out, and if we cant figure it out, I'll call my mechanic buddy to see what is going down.

I hope that it isnt those two sensors, or else I will have to save my money for a while to pay for it, I hope that it is a intermittent problem that I can just watch my tripodometer for. (~280 miles to be safe).

I hope it goes away, and thanks for all the help.

[hvmercy]

Originally posted by cian36n
Kamera,
I have had my car since October of last year. When I got it it had 62,000 miles on it and it now has 67,000. This is the first time that I noticed it, and I hope it is the last time that it ever comes up. It could quite possibly be that I over filled it, as I noticed that the gauge wasnt working after about 30 seconds of filling my car.

I checked the seal around my filler cap, and it looks fine to me. So I dont think that is a problem.

Speaking on the vacuum leak problem, I'll talk to my brother about that and see what we can find out, and if we cant figure it out, I'll call my mechanic buddy to see what is going down.

I hope that it isnt those two sensors, or else I will have to save my money for a while to pay for it, I hope that it is a intermittent problem that I can just watch my tripodometer for. (~280 miles to be safe).

I hope it goes away, and thanks for all the help.

cian36n,
Before you do anything major, replace your battery first.
I remember a couple of years ago I was having the same problems with my gauges and I thought, wtf, what's going on
now? I guess it was a sign that my battery was gonna crap out
soon.
Do this and see what happens. At least it's not that expensive.

hvmercy

[cian36n]

hvmercy,
I was thinking about the battery as well, but I also thought that I couldnt be the battery because it is just that one gauge that is not working properly, and all the others are working as they should. But, I will go home today after school and check my battery and see if it has the proper amount of volts.

Thanks,

Ian

[kameraguy]

cian, interesting. I purchased my car @ 63K on the clock and noticed my first signs of fuel guage issues at around 65K or so. An odd coincidence!

hvmercy, interesting theory. I take it you changed your battery and have not had the issue since?

I will be able to test the battery theory as i'm getting my battery changed this week. It should be an easy test for me as I almost always have fuel gauge issues now. So when I get my car back my first tank should hopefully register as full.

[cian36n]

Kamera,
A very odd coincidence. ;) Sounds like a plan for the testing of the battery theory. Do you think that it is possible that there is a bad connection on the back of the gauge cluster?

Ian

[kameraguy]

Originally posted by manny
They didn't say how much it would have cost, and I sure didn't want to ask.
You can lay the blame for this annoyance on the sh...t fuel we have. ;)

manny, would different "brand" fuels make any diff? did you notice this problem was less frequent with a particular station, such as Chevron or 76?

[kameraguy]

Originally posted by cian36n
Kamera,
A very odd coincidence. ;) Sounds like a plan for the testing of the battery theory. Do you think that it is possible that there is a bad connection on the back of the gauge cluster?

Ian

sounds like something easy enough to check. although quite frankly i haven't pulled my cluster out before. I do have the tool though. Anyone know if it will be a simple connector or is it more complicated?

[hvmercy]

The f'in dealership was gonna replace the instument cluster
and charge me $900. I asked them if it will solve the problem;
They couldn't answer for sure so I left it alone for about 1 month
and finally one morning I was going to start the car and no juice
to crank it. I went to Sears and bought a brand new battery for
like $85 (not sure). Went back home and did the swap myself
and voila!, car started fine, instrument gauges were all normal.
Never had any problems with the gauges since then.

Go try it, at least you're buying new battery right.

Oh wait, come to think of it, my car's mileage around that
time was like ~63000 miles. :confused: Is it coincidence?

Hvmercy

[manny]

Originally posted by kameraguy
manny, would different "brand" fuels make any diff? did you notice this problem was less frequent with a particular station, such as Chevron or 76?

I believe fuelbrand may have something to do with it.
Being in Canada, we don't have the same brands as you do, so I can't advise you on this.
As I said earlier, you may want to try a few cans/bottles of fuelsystem cleaner as well.
Btw. the problem is NOT the gauge in the dash, it is the fuelsenders in the tank. ;)

[steponit]

whoa.. that's crazy.. cuz my gauge started to get crazy around 65,ooo mi. as well. our 202's have become possessed.

[kameraguy]

63-65k....it's a damn conspiracy i tell ya....:bandit:

[joboo]

My car does the same thing whenever I fill up the tank. Dealer told me it was the fuel sending units too. Big bucks to replace them both. My 95 C36 has 110K kms. About the same as you guys. I also had the replace the battery around Xmas time. I thought it solved the problem as the gauge worked for a few weeks fine and then back to not working after I fill up. However; it will start to work about 150kms into the tank. I have no idea what his could be so I go by the trip meter. I get about 400kms per tank.

[nokia8860]

Kameraguy,

There are two connections on the back of the cluster. When you pop out the cluster part way you have to reach in and press a tab to release a err.... release then the harness will free itself. One harness on each side.

What is weird with my gauge is like I'll fill up full turn on the car watch the needle swing up then fall back down to like the off posistion but the low fuel light wont come on.

Then about 25mins of driving you see it slowly get past the low fuel indicator.

Then you turn off the car goto work get in for lunch and bamm it works.

It must be a very crappy sending unit they got in that fuel tank.

But I agree changing the cluster should not be considered a fix for this. Its something with the sending unit.

[manny]

nokia

My car exhibited the very same symptoms as yours.
It's the SENDING UNITS. ;)

[nokia8860]

Originally posted by manny
nokia

My car exhibited the very same symptoms as yours.
It's the SENDING UNITS. ;)

w3rd!

[cian36n]

I just put about 50 miles on my car since the last time that I filled up and now its working properly, still some crazy shit.

Ian

[smartkey]

I have a '98 C280 that just past 50,000 and ever since I have had it the fuel gauge has been behaving strangely every time I fill up the tank like really full. I have had my mechanic put his code scanner on the car and I have been getting codes such as fuel level sensor malfuction, He said it may be the gauge but not codes have come up for the gauge itself. I think that it is the sender in the tank but now you guy are saying that there are two Ouch the repair bill is going to be a punch in the gut because I have looked and the car and there is now way to access the tank senders unless you drop the tank. I am keep my fingers crossed to see what happens.

[delisi2322]

I have had the same problem for the last 2 years. I took it to a shop to fix it through warranty but the warranty company would not fix the problem. i think the reason why is because sometimes it works and sometimes it doesn't. I'm going to try again to fix it throough warranty only because i got a new warranty company. I'm so use to it but i stilll want the problem fixed because it's really annoying:p

[ryhi]

damn..my car just go posessed!!! except my fuel level stays UP!! at first, it was all the way down with the fuel light on....but now it just stays up.... has anyone figured anything? maybe disconnecting the battery? i would disconnect my battery, but i dont want to lose all the pics vids n settings on my headunit!! someone try it and let us know!!

[Rocky]

This is a common problem on these cars. It's pretty expensive to fix if i recall and it's not a DIY'er job. Needs some special tool or something and is located in the gas tank..a sensor or soemthing I don't remember.

[rad2000]

My fuel gauge started acting up at about....you guessed it....60K miles. Dealer replaced the sender unit free of charge. No more problems until about 105K, then the same damn thing. Both times:

--Happens after fillup
--External factors (e.g., temperature, battery condition, brand of fuel) seem to have no effect
--Begins working again at about 3/4 tank
--When turning key to "on" position (not cranking) with a nearly full tank, needle does a dance then either goes down to empty or up to full. If it goes to empty, sometimes I can turn it off, turn it back on, and it will go up to full. Once up to full, it seems to keep working for the remainder of the trip.

I guess I'll have to live with it. It registers correctly when it's important (<3/4 tank) and I reset the trip odometer after every fillup. The cost of repair is just too high.

Incidentally, I think there is no excuse for such a pervasive problem. MBs are sold worldwide, many in areas with worse gasoline than the US. I've driven other cars upward of 150K miles without any fuel gauge problems. Obviously, MB knows of this problem, otherwise they wouldn't have replaced the sender unit(s) out of the warranty period. Apparently, they did not redesign the part to avoid the problem, though.

Rad2000
1995 C280

[Rocky]

Word of advice. Never let your fuel low indicator light up. Always fill above 1/4 tank.

I have never..maybve once or twice let the low fuel light indicator come on..never had a fuel gauge problem.

[joboo]

If this is a re-occuring problem that we all have, it should be called back under a recall??? am I out of line?

[delisi2322]

your defintely right everyone is having this problem. It's not just a coincidence that everyone is having this problem

[Rocky]

Well.I see the engine wiring harness a big problem as well as the head gasket and maybe the MAS. I didn;t see them recall those items, I doubt they will recall the gas thing.

[kameraguy]

btw- with my new battery the first full tank had the exact same issue. I need a couple more fill-ups to be sure, but it seems the problem fixes itself quicker though. But at any rate, the new battery didn't solve the issue. Maybe helped it a little? Will keep an eye on this.

And yes, this is annoying.

Actually, does anyone know how to get a recall going? Is this something owners can get together to start? Because it seems like there are a LOT of MB owners with this issue. i don't care if it's because of "crappy" $2.50/gal super-unleaded gas. It's still a problem that's not our fault!

[joboo]

Yes, I vote for recall. RECALL!!! RECALL!!! RECALL!!!

[moebiusgold]

I've had my gas gauge act up twice after fill ups on the 36. I was reading in news yeasterday about high sulfur content in gas refined in La. that affected about 500 stations in the S and Fl. Shell and Texaco. It was corroding the sending units. So if you folks in Ca. have the problem, because you have by law very low Sulfur content gas, equivalent to Europe I think, it might be a mechanical issue with the sending units. The 2 times mine messed up I really tried to squeeze every last drop in drove 2 miles, and the next time I started it, was the problem. The second time it went to 1/2 full after about 20 miles then in about 25 more it shot up to full. Hm. :(