Fuel gauge question... W202 C43

[gaz_l]

Well, my Mercedes ownership is off to a dodgy start.. first fault after only 2 days !

Filled up yesterday (first time since I bought it, hadn't been over 1/2 a tank before that). Paid, got back in, went to reset the trip meter to try and work out the economy (or lack thereof) over the next tank, but the fuel gauge had dropped down to zero.

Today it did flick up to full briefly but then dropped again. This happened a couple of times. The reserve light has come on and off a few times while the gauge has been reading zero.

I've done a little research and the consensus seems to be that Mercedes fuel gauges are not the greatest thing since sliced bread, does anyone have any advice as to anything I can check out myself (I'm an electronics engineer, so I'm quite competent at fault-finding), failing that how much is it likely to cost to get fixed?

Thanks in advance,

Cheers,

Gaz

 

[GrahamC230K]

Had a similar thing happen once. If you filled it to the brim, I'd give it a few days (ok trips in a C43 ) to see if it sorts itself out.

 

[ralphsanders]

My 2001 C200 K does it as well!

 

[converse120]

Mine (a '99 with 61K) has recently started doing it as well, normally only the first day after filling up. One time it won't work, the next time it will. Fuel Senders. Not sure about what you could check though - need more knowledgeable people than me !

Think I read somewhere on here it's a couple of hundred quid fix, but don't remember if that was just the parts. Or I could be completely wrong and it might be a lot more ! Sorry ! Sure someone else will come along soon and give you the bad news.

I'm going to leave mine until it gets a lot worse, i.e. does it all the time.

Cheers

Ian

 

[IanA2]

Maybe I've missed a trick here but does it really matter? I always fill up at a quarter tank. As for ecomomy, on a 500SL there isn't any, much the same as a C43AMG I would have thought.

 

[rajinder_1]

Guys,
I have had similar problems on w202 and r129, i ahve found that if you use Forte gas treatment the problem seems to rectify. Now this is only my experience but the 129 has only done recently but the 202 done it ages ago.
Costs £10 and is supoosed to be good fuel system cleaner.
Give it a go only a tenner to loose if it dont work...

Let us know what your outcome is.

Raj

PS best result is to put in before you fill the tank up so it mixes in oh and you might need a funnel other wise gets messy and it smells...

 

[DITTRICH]

Rajinder is right.
Try his suggestion.
My 'fix' was simply to fill up with with a few tanks of more expensive fuel to supposedly 'clean' the tank/sender units. Well anyway it worked for me.
Too many people rush to replace parts when, I suspect, they are just dirty.
Les

 

[SilverSaloon]

hi

i had this problem with my CLK when i 1st bought it.

It is probably the fuel sender(s). There were two on my CLK - both corroded and one was replaced with the newer updates ones from Merc. The other one was so corroded it didnt come off, but replacing just the one fixed the problem.

i would check this if i were you....

EDIT: Price was £40 for 1 sender unit (iirc).

hope this helps!

Derek

 

[gaz_l]

Well, had the chance to give the car a run today and burn some fuel off. 200 mile round trip, gauge stuck on zero all the way down. Switched off when we arrived (with 130+ miles on the trip meter). Went to move on (had a few local trips to make), the gauge went up to about 3/4 tank and started to drop normally, although I doubted that we had only used 1/4 tank in 130 miles, but don't know how linear it is.

Before the trip home I stopped to fill it up again, the gauge goes straight down to zero . Stays on zero all the way home, stop to drop off some people down the road, get back in the car and the gauge goes straight back up to full. WTF?

I think the sender must be U/S... I'll see how it goes but it seems to be making up random numbers!

Cheers,

Gaz