Hi. I have a MB E300 TDT 1998 that just stopped working today.

My wife started it as usual today, and waited a minute for my son before she was about to drive. Then it suddenly stopped.

I was close by, so I started to look into it. Tried to start it, and it "almost" started - but then later it has been "dead". I can roll the engine with the starter, but no sign of ignition.

After checking fuses etc, I started to look closer. Saw that there is air in the transparent tubes that goes to and from the main diesel filter. The filter is not old, and as far as I can see all O-rings are in place. It has also run without error since the filter change appr 5 months ago. So I assume that if there is an air leak, it's not in the filter housing.

You can see the tube with air inside here:

See the bigger iage here: http://bildr.no/view/1624739

When I try the starter, air and diesel seams to move into the filter. Most air.

Am I right when I assume that this is the reason it wont start? - And if air is moving here, where is it most likely to enter into the system?

Probably before the diesel pump and after the tank then? Is this a known error with this car?

Thank you for helping :-)

 

No, not FULL tank. But have 1/4 full tank. Have never been problems before.

Note: On another mercedes-forum there was a person saying that on this Mercedes the iron pipe can rust. Especially at the back, and thus make room for air to come into the diesel between the tank and the pump. That would not leak diesel out, but air in.

 

The comment about having a full tank of fuel is there because Fuel Gauges and the Fuel Sending unit inside of the Fuel Tank have been know to Fail and give the wrong reading on the Gauge.
If you fill the Tank you know for sure that is not the case.

Another way to check for Fuel tank issues is to run a separate Fuel inlet Hose to a container of Clean Diesel Fuel for testing bypassing the Tank completely.

If there is some organism growing in your Fuel Tank it can easily plug up new Fuel Filters.
Pull the Primary Filter (not the Spin-on Filter) and see if you can see any greenis-gary-black stuff on it.
And, remember that you have a Screen in the Fuel tank that can also be come plugged up.

O-rings even though they are present can get old and stiff and not seal. Air can come in the suction side of those lines if that is so and if you have a Fuel Heater that has been a know source of Air leaks when the O-rings go bad.

If your shutoff works using Vacuum disconnect the Vacuum Line at the Vacuum Shutoff on the Fuel Injection Pump. If that allows you to start and run you are getting Vacuum to that Valve when you are not supposed to.

Try starting without the Fuel Tank Fill Cap on. If you can start after that your Fuel Tank Vent is plugged.

 

I spent some money on my 87 300D Turbo when it would not start and had to be towed to the dealer TWICE. The first time they changed parts and got it started. Second time they actually figured out what it was. What had happened was that I had parked the car both time on an uphill drive way. The engine was quite a bit higher than the gas tank. The seals of the metal lines from the injection pump at the engine attachment points had began to leak. While the car was parked for a couple of days, air entered at the faulty seals and fuel drained back to the tank. On this particular model it is a real bitch to get rid of the air in the lines. You practically have to wear out the starter before you get the engine to run again. If any one has this problem, it might help to have a full tank and then park the car pointing down hill. Also, if you detect fuel seepage between the injection pump and the engine, it's time to get the seals replaced.

 

This is one of the main problems of the w210 diesels. They don't work properly when the diesel fuel isn't clean. To make it work, you have to be sure of what fuel you are using.