'97 C class petrol gauge reading empty

[altreed]

Hi,

Last night I filled my car with fuel but this morning it has the gauge displaying very low and the light is on.

Can anyone give some advice where to look for the fault on this, I'm sure it is a 'standard' fault/failure.

Thanks

 

[heckflosse]

Most likely the fuel tank sender unit.

 

[sunil sood]

happened to me once or twice.

in my case it happened after i topped up the fuel tank to the brim.

got better itself and has not happened since i avoid topping up the the fuel tank to the brim.

 

[altreed]

Thanks.

In fact like Sunil it has fixed itself 8) , and similarly I may have filled it unusually full in this case.

What a mysterious feature! :roll:

Out of interest, how difficult is it to change the sender unit? Also does anyone know the cost of the parts??

Many thanks

 

[Stewart Smith]

Have had exactly the same happen to me recently. don't trust the guage at the moment, although its now started to read a level.
Did it evre happen again Altreed?

 

[pluggers]

Ive had this strange occurance as well Ive had the car for say 14 months using normal unleaded, not a problem.Then after 3 weeks of using Shell Optimax the guage went barmy.So I went back to useing normal unleaded again and everything is back to normal, and has been normal for about 6 months too date.

 

[willydog]

my dad had the same problem on his C180, the mechanic said it was a faulty fuel sender unit and you need to wait until the tank is almost empty
before you can change it.

 

[guydewdney]

i took my c220 cdi back and they repalced it under warrenty - saying it was a known prob in the uk due to all the crap they put in uk fuel

bnever fill up from a supermarket petrol station....

 

[dwhattam]

I get this once in while on my CLK, not sure if it would be covered by my warranty given that the car is 5yrs old!

I've just got use to it and try not to 'neck' the petrol tank anymore, which seems to stop it happening, didn't notice if filling with different fuel or from a different supplier made any dofference I just know that if I really fill her up it happens !

 

[jimsinessex]

My CLK (1999) does exactly the same but only about 1 in 20 fill-ups. I always brim the tank in exactlty the same way, wait for first cut-out then carry on till next round pound is reached, can pinpoint no special reason why the occasional fill-up causes this problem. It did not happen until the car was about 3 yrs old. When it happens the needle slowly (over about 5 mins rises halfway through the orange reserve zone and the orange light goes on and off slowly. It almost always seturns to normal next time the ignition is turned on but never resets itself until then. Has anyone had this result in eventual total failure of the level indication?
It has got me intrigued and I would love to know the reason.

 

[Andy]

Hi all

Yes its a known problem with C class's including CLK'S. The cause is the sulpher in the fuel effects the contacts on the sender. The fault codes do not as a rule tell you which side is the problem. So they are fitted as a pair. 1 is £40.00 odd & the other side is a little over £50 all plus vat. MB give you 1.5hr to replace. Need to drain the tanks if you are doing it your self. Senders at the bottom of the tanks covered by a couple of black plastic covers both sides. They are held in by a big ring & there is a special tool to remove. But when you look at it you may be able to improvise!!!!!!


Regards

Andy @ www.mercedesservicing.com

 

[max200]

Ive also just started experienceing this, filled tank up, shows completely empty and warning light comes and goes.
After about 100 miles it seems to rectify itself and then on filling up, back comes the fault. Cant rely on it. Bit of a pain really.

 

[philharve]

Brimming the petrol in the tank

Hi All

This is an interesting thread and I will be keeping a close eye on my fuel gauge for any irregular behaviour.

The owner's manual does warn of not brimming the tank but they don't say why.

I put in around another £1s worth of fuel after the fuel pump cuts out which is probably well short of actually brimming the tank. Filling to this level does give a fuel gauge reading above the maximum level.

I wonder if brimming the tank damages the sender? Is the sensor of the float variety?

I don't see that filling with a different make of fuel should make any difference. Still ... it's an interesting observation.

REGARDS Phil