1999 C250 TD Out of Diesel at 1/4 tank

[KPmerctastic]

Hi
I have had a brief look to see if anyone has written about this before, but nothing available. I ran out of diesel going uphill, but the fuel guage was showing 1/4 tank remaining. I took it to a local garage to see if they could fix it. They said it is very common and there was not much they could do for me. Do any of you know this to be a problem? If so is there a way to fix it? I would appreciate your help.

 

[c250 turbo diesel]

Answer

Put in a non return valve on you fuel line, put a new diesel filter on !

 

[joe bloggs]

Tank units (2) on these cars are well known for trouble, we used to change hundreds, difficult to tell which one is faulty, so we used to change both (much to the dislike of DCUK warranty) there is one on each side of the fuel tank.

 

[KPmerctastic]

Thanks for your replies.
I have been away, hence the delay with my thanks. I have replaced the diesel filter, but have not been able to locate a non-return valve. MB don't carry one, any suggestions?
What are these 2 tank units you refer to? Someone told me the C Class has a kidney shaped tank, and probably needs a pick-up pump each side to collect fuel. Is there any truth in this, and where can I get them?
I thought I would try and see if the fuel filter worked, but it ran out again at 1/4 tank. It was a real swine to get started again, even though someone has thoughtfully fitted a hand priming pump. There did seem to be a lot of air in the clear hoses around the filter though

 

[catgate]

"What are these 2 tank units you refer to? Someone told me the C Class has a kidney shaped tank, and probably needs a pick-up pump each side to collect fuel. Is there any truth in this, and where can I get them?"

It really is a fool of a system. Fuel is transfered from the "filler cap" half of the tank to the other by means of a syphon system transfering fuel over the "Hump", provided by MB for the benefit of the prop.shaft. Fuel is taken out of the non fillercap side by the lift pump (or in the case of the C220 by the injector pump). The surplus is returned from the pump/pumps back to the filler cap side of the tank. The two fuel gauge sender units are needed to give a reasonable guess at what is actually in the total tank (there is probably an integrator built into the ECU).
How do I know? Well I had to replace both the injector pump and the tank on my C220 for this problem and we cut the old tank up to see what was going on. It was a leaking pipe within.

 

[jberks]

Are you sure you had 1/4 of a tank?
The fuel guage senders on the C are notorious for sticking. Fortunately for me, when mine went, it just refused to show any more than 3/4 but it could just as easily refuse to drop below 1/4.

 

[fawas]

Fuel tank problem

I had same problem in my c220 I was stack in many placese, then I took to a local garage they told me that, there is two component of fuel tank, when fuel bringing to engine it's take from one component so other side there is still fuel in the other side that is why fuel cage showing, I didn't solve the problem yet, now I fill up full tank.

 

[chizzel89]

The fuel tanks are indeed a joke. Even when theyre working properly, the engines start to draw up air bubbles when getting near a quarter tank. There are two solutions. One is to take out the fuel senders and use a hole saw on the bottom of the tanks and use plumbing fittings to join them under the prop shaft (you can even take your fuel feed using a T piece in this pipe). A few people have done this and haven't yet ripped the pipe off on high ground.

The safer way of doing it is to fit a facet pump inbetween the tanks so the return side is constantly being pumped dry into the feed side by the facet pump.

There is a Chrysler with saddle tanks which uses this exact principle.

 

[gizze]

I bought an E320 V6 and that would never drop below 1/4 tank on the guage, I put in a bottle of fuel cleaner and it worked on teh first tank, it said add 1/8th bottle, but I put the whole lot in.

 

[Dikdik]

Its a real pain. Anyone give us a fix for this please


http://forums.mercedesclub.org.uk/showthread.php?t=12494

 

[spock500]

Its a real pain. Anyone give us a fix for this please


http://forums.mercedesclub.org.uk/showthread.php?t=12494

Tis a link to this thread?

Have you checked the basics such as O rings on the fuel lines?

Are you using bio or similar fuel?

 

[gizze]

Also, how much fuel did it take to fill it right up again?

If you used 64 litres you have a big issue, if it only took 45 litres then you just need some cleaner adding.