Diesel just quit running today - PeachParts Mercedes-Benz Forum

nelbur · #1 11-11-2012, 02:37 PM

I got about a block away from my home, and my '97 E 300 D just quit running. No drama. It just no longer responded to the accelerator. It seems to fire on a cylinder or two every rev while cranking it but it will not start. The fuel lines to and from the final filter are full of fuel, but I can see a couple of bubbles while cranking. The rest are too dark to see through. I'm guessing it is a no fuel issue, but I know I have slightly less than half a tank on the gauge (210 miles on trip meter). I am due for fuel filters but can't see them causing so quick a problem with no previous symptoms. How would I check the lift pump? Any other suggestions as to what to check?

pawoSD · #2 11-11-2012, 02:47 PM

I would suspect air leak at one of the fittings or failed lift pump.

Check lift pump by disconnecting the tank return line/fitting, putting into a container and cranking to see how much fuel it moves, if little to none, then its toast.

Diesel911 · #3 11-11-2012, 02:53 PM

A plugged Filter is still the most likely casue. I that turns out to be the case you can quickly have your Car back on the Road.

Diesel911 · #4 11-11-2012, 03:00 PM

Apparently your Shutoff Solenoid is Electric.

If it gets no Voltage I am guessing it shuts off.

Jeremy5848 · #5 11-11-2012, 03:37 PM

I had a starting problem with my '96 E300 (very similar to your '97) some years ago. My problem turned out to be the starter motor but one of the suggestions at that time was the K40 relay, which powers the fuel solenoid described above. The K40 relay is located in the black plastic instrument case under the hood, where one might expect the battery to be. K40 is sort of the W210 version of the OVP relay in W124 and other older Mercedes designs.

I was told that K40 can go flakey as it gets old and cause the car to suddenly stop for no apparent reason. Sometimes the unit will start working on its own and be fine until next time. Replacing the K40 relay fixes the problem. Remove the cover and K40 can be unplugged and removed. It's not expensive, probably less than US$100 from Pelican or your dealer. Part number 210 540 03 72 in my '96, probably the same in your car (but check to be sure).

Jeremy

nelbur · #6 11-12-2012, 12:06 AM

Thanks for the ideas. I will start checking things out in the morning.

vstech · #7 11-12-2012, 07:38 AM

start with fresh fuel filters first...

muleears · #8 11-12-2012, 08:58 AM

As a former owner of a '98 E300, when I had bubbles in the fuel lines it made it very hard to start but didn't make it stall once running. It would have to be a pretty big air leak to stop it completely. Have you messed with the fuel lines at all? The "horseshoe" clips on them have to be pulled out, away from the fuel line to clamp them. Kind of counter intuitive.

I have a shut off valve for the car, it's dusty but it's yours for the postage if you want it. It's for a '98 but I think it would work on yours. I would think if the shut off valve gets no power and shuts it would not run at all, even on one cylinder.

My advice would be 1. All fuel filters and be sure to put the correct MERCEDES O ring on the pre filter. It is NOT a standard size O ring. My Indy had put the wrong size one in mine while chasing the hard start problem and made it much worse. Maybe check the tank strainer too. 3. Then check the K40. 4. Lift pump. 5. SOV.

Let us know what you come up with, especially if you fix it!

nelbur · #9 11-12-2012, 05:28 PM

Well, it is running again. The lift pump was pumping fuel but the quantities were not impressive compared to the gassers I have worked with in the past. I had the filters but had not had the time to install them. Funny how one can make time when necessary. I filled the filters with Diesel Purge. The o-ring on the fuel line fitting on the top of the primary filter was too compressed to feel like it was sealing, so I replaced that line, and another, with new lines. Now all the clear lines are new. It took a heck of a lot of cranking to get things primed up. This is the first diesel I have owned with NO hand pump to help prime things.

Since I changed the lines as well as the filters, I think the spin on filter was the problem, but can't be 100% sure. Thanks for the suggestions. I didn't think the filter would shut me down with no warning, but I was apparently "wrong again".

tyl604 · #10 11-12-2012, 09:04 PM

Are you thinking the spin on filter was clogged or poorly sealed, enough to cause the engine not to run?

nelbur · #11 11-13-2012, 08:19 PM

I am thinking the spin on filter was plugged up and not passing fuel. The reason I am not sure is because the new primary filter seemed to have a larger ID where the fuel line fitting plugs in to it. The old stiff o-ring did not feel like it was sealing, so I used a new fuel line with new o-rings, and while I was at it I replaced one other clear line, so now they are all new. By replacing these two fuel lines at the same time as the filters I added another variable so it is hard to be sure the replaced lines were guilt free.