MB E300TDT 210 -Just stopped, will not start.
 

Hi, I have a 1998 E300 TDT that just stopped yesterday. Had just started it, reversed 5 meters, put it in Drive and waited for my son. Then it stopped.

My diesel filter is appr 5-6 months old. I emptied it to see if there was some water in it, but none.

I had my wife crank the engine, and I see air in the transparent fuel lines. Especially in #83.

I also opened the pre-filter just a little, and it was almost empty. Half full of diesel. Is that normal?

My thought is that the iron pipe that runs from the tank to the engine room may have get a whole (rust) and sucks in air.

Any ideas how I can test if that is the case? - or any other idea of what is wrong?

http://prebenolsens.com/606fuelsystem.jpg

Well my first suggestion would be to get a jerry can and dump a few gallons of diesel in the tank. Maybe she's empty. FUel gauges don't always work..

There should be enough diesel on the tank. Filled it up to between 1/4 and 1/2 full on Thursday afternoon. Then this happened on Saturday morning. In between the car has only moved max. 70 km.

Right now I only have 3 liters of diesel in a small can, and may be able to borrow a car to try fill up more. But as mentioned I am pretty sure there is diesel in the tank.

Try opening the fuel cap, is there a sudden and abnormally large inrush of air? If so it could be a clogged tank vent. I'm not that familiar with the W210 but if it has a tank strainer (most do) then that could be clogged too...

You ought to have air prior to line 83 as that is on the pressure side of the lift pump, as such, fuel should come out, but air should not leak in.

Follow the fuel path proir to line 4 and look for air. Repalce every oring prior to that point. fuelflow.JPG (image)

Get the tank filled up to ~1/2, raise the rear end (use a jack and set the tires of some blocks), fill the pre-filter and canister filter with fuel, then crank to reprime. If it sounds like it is going to catch, keeping cranking 2-3 secs after its running to make certain it keeps firing. Won't hurt the starter.

You should also make certain that your shut off valve opens too.

Hood up, window down, turn key to pos 2, listen for click of SOV openning. No click, no fuel, no start.

Hi folks, I have an update :-)

I finally got it fired up, but haven't found the cause of the stop. Now I have had it running for 7 days or so, but now it has stopped again.

@TMAllison : Thank you for the flow chart for the engine. It surely was not logical to me that there was a tube #3 that flow in that direction as you have drawn. :-)

Yesterday I tried for 2 hours to get the air out and start it, but no luck. I have had a considerable number of diesel "drops" in my mouth, trying to suck the tubes etc. A man has to do what a man has to do, right? Doesn't taste that bad actually, but might not be the most healthy fluid... ;-)

This is what I have seen:
When the engine did start:
when I revved it I saw air in tube #2, but only very little in tube #1.
So I guess the air is leaking in though the o-ring in the pre-filter, at the end of tube #1 or in the beginning of tube #2.

What I did yesterday, was to manually fill the pre-filter, and then take off tube #4 at the end
(the end that goes into the filter housing) and then suck there. I got a lot of air moving out, and the pre-filter emptied.

I redid this until I had what I believe was solid diesel from the pre-filter to tube #4.
(I was stranded on a parking lot way far from my house, so I didn't have my tools there. Only some pipes etc.)

I also made sure the dieselfilter was filled to the brim with diesel.

But it wont start. When trying to start it is air "all over" in #2 and #4. And #4 gets filled with air. I can't see #3 very well. But from my point of view it seams like a heavy air leak now. I tried to start my car at least 12 long lasting times yesterday. Got power from my friend's Auto A8 2,5 diesel. Good to be able to use that car for something ;-)

I have tried with o-rings from my local workshop, but those were not original ones.

SO:
I think I ought to exchange all the tubes. I believe those tubes comes complete, with o-rings and the black ends. Is that true?

Where can I buy them?

Is it possible to change #3 without removing the air inlet to the engine?

What would you have done in my situation?

Here are the oring sizes and counts. http://www.peachparts.com/shopforum/diesel-discussion/177588-om606-962-o-ring-size.html

Repalce all of them and then stop openning the fuel lines up, all you are doing is letting more air in and starting over again each time.

Dump +1/2 tank of fuel in the fuel tank, it helps.

Jack the rear of the car up a few inches (10cm), that helps too.

Hi folks, I have now NEW o-rings on tube 1, 2, 3 and 4 on this drawing

Yet, the engine doesn't start. I also see that the tube #4 is filled with air.

But tube #2 has diesel.

Tube #3 is too hard to see from my angle. But it seams like there is diesel in that one.

Where can is suck air?

Note: When I fill the pre-filter with diesel and then blow in it (to blow the diesel into the system), I somewhere hear a "wistle" sound. Can this be a cracked diesel tube? I can not see any crack, but it might still be one?

Shut off Valve oring can let air in.

I'd replace the oring on every fuel line. Start fresh so you aren't doing it again next week when a different one fails.

Where exact is the shut off valve o-ring?

Is that the thing that is between tube #5 and #3 on the drawing (2 posts up) ?

EDIT:
I found this image in another thread about o-rings here. Is it the yellow marked o-ring here?

Hmmm.

I found this video:
99 Mercedes-Benz E300 Turbodiesel Fuel Leak - YouTube

How is the shut off valve fastened? Are there any bolts to it, or just to pull out?

Just a side note:
Here is a thread regarding a Mercedes / Bosch blunder when designing this fuel system. Bosch intended to have a 10mm fuel line from the tank to the diesel heater. But MB made that a 8mm in stead. That have given problems regarding power, since the flow rate of the fuel is too low.

The vacuum is also so high (in the pulses) that the diesel viporases and gives "air" bubbles in the system - even though no o-rings leaks there are bubbles in the system.

Well, I am so eager to get to my car and find the shut off valve o-ring. That is the only one that is not yet changed. ;-)

Just trying to find how to remove the SOV.. :-)

The SOV has 2 screws holding it on, going straight into the side of the pump body. Torx or allen I think. Once you remove the screws, just wiggle the valve and tug on it and it should work loose.

When replacing the O-ring, note that it only goes on the valve up to the little shoulder, not all the way up to the valve body itself.

Like this:

http://i3.photobucket.com/albums/y71...s/P5080087.jpg

Awesome!

Thank you. Anybody who knows what size torx it is? I need to go to my car by car, and I don't have too much tools in my cars.

Allen, is that the same as umbraco?