99 e300td injector pump leak - PeachParts Mercedes-Benz Forum

crmont · #1 10-08-2004, 08:43 PM

:EDIT:
B100, Waste Vegetable Oil (WVO), Low Sulfur Diesel (LSD), and Ultra Low Sulfur Diesel (ULSD) deteriorates Buna-N Rubber O-rings, Viton rubber holds up better.
:END EDIT:

99 e300td

I have a leak at the injector pump. It's not in the pump itself, but the block that feeds the pump (I think). I have seen other threads reguarding leaks but I thought I would post this picture Perhaps someone has seen a thread.

John

barkford · #2 10-08-2004, 09:23 PM

My 98 also has a small amount ( a seep I would call it ) of fuel on top of the pump. There's nothing dripping but if you lean right over the pump and sniff, it's definitely a waft o diesel.

crmont · #3 10-09-2004, 01:08 PM

My leak bubbles a little but seals up when the engine warms up. Has anyone here had this repaired yet? tia

crmont · #4 10-10-2004, 12:14 AM

Does anyone know where to get an exploded parts view of this pump?

michakaveli · #5 10-10-2004, 02:19 AM

sounds like the shutoff valve.... do a search.

Rick Miley · #6 10-10-2004, 08:23 AM

That's most likely leaking plastic fuel lines. If you have small hands, you can replace all but one of them without removing the intake manifold. Simply remove the nut that holds down the washer bottle, lift it up and set it aside. Then you can reach in and get to the fuel lines. I'll post a diagram later today along with part numbers. If the shutoff solenoid (black box) is leaking, then you'll see fuel dripping down underneath it while the engine is running. It wouldn't make a mess on top of the pump.

crmont · #7 10-10-2004, 12:08 PM

I can see the leak bubbling out right where the arrow is. It does leak out the top.

Rick Miley · #8 10-10-2004, 05:01 PM

That's really odd. If it really is coming out between the shutoff valve and the injection pump, then you're going to have to replace the seal ring that is under there. Unfortunately, that means you'll have to take the intake manifold off to get to it. While you're in there, I would recommend replacing all those plastic fuel lines as well. They're not very expensive (under $10 each) and they are prone to leakage, especially when you disturb them. The shutoff valve (black box) is plastic and known to develop leaks as well. That's what I just went through replacing.

The exploded view you wanted is not in one drawing, it is in three that I will attach below. The first one shows the shutoff valve, which has three fuel lines (2 on top, 1 on bottom) attached to it. It has a tube that extends into the injection pump, and that tube has the seal ring on it. That seal ring is very easy to roll or pinch, so be careful when installing. The shutoff valve is held to the i.p. with two allen head bolts. The parts you're interested in from this drawing are:
32 - A 021 997 75 48 Seal Ring
29 - A 000 078 44 49 Shut-off valve

The next picture shows all the fuel lines that I recommend replacing. The clips on the ends of these lines are kind of counter-intuitive. You push the white part in (toward the hose) to release the line. They require quite a bit of force to pull out and push in, so be prepared to wrestle with them. Again, the seal rings are very easy to get out of place when installing. Part numbers for this picture:
32 - A 605 070 14 32 Line from thermostat to prefilter
119 - A 606 070 05 32 Return line from i.p. to fuel filter
126 - A 017 997 22 48 Seal Ring - fuel line and overflow valve
128 - N 007603 012102 Seal Ring - fuel line and overflow valve on i.p.
95 - A 605 070 15 32 Line from fuel filter to shut-off valve
83 - A 606 070 04 32 Line from feed pump to fuel filter
56 - A 605 070 07 32 Line from prefilter to shut-off valve
74 - A 605 070 08 32 Line from feed pump to shut-off valve

Now, any time you take the intake manifold off, you'll need to replace all the little plastic clips. They get brittle and break, so take them all off before you remove the manifold so that no plastic bits fall down into your engine! Also remove the black plastic cover over the valve cover, to make it easier to work here. Parts you'll need:
95 - A 603 078 01 41 Bracket (Qty 7)
92 - A 601 078 03 86 Shim (Qty 7)
104 - A 601 078 26 41 Bracket (Qty 2)

And finally, you'll need:
A 606 141 01 80 Intake Manifold Gasket

Look up a post by Lightman on how to replace glow plugs. He has detailed instructions and pictures for removing the intake manifold.

crmont · #9 10-10-2004, 06:18 PM

The car now stumbles and dies on first startup attempt. It doesn't seem to matter if it is warm or cold. On the second (or third) attempt it stumbles but starts and smoothes out. I'm going to start with the fuel solinoid. I suppose glow plugs would be in order if I'm going that far. Are there any other starting issues I should know about? I'll keep searching.

Mike thank you for your info. I cannot tell you how much those part numbers mean. Your dead on with that #32 o-ring. Seems strange to leak there but I saw bubbles coming out of that spot. It's possible the fuel originated from a fuel line leak on top of the fuel solinoid. That might then indicate an air leak? (bubbles). Is that o-ring under positive pressure? I'm pretty sure it's simplly leaking fuel at the spot I have identivied in the picture. I see the fuel lines but I'm not up to speed on the direction of flow of the fuel yet.

crmont · #10 10-10-2004, 06:20 PM

btw it's not possible to remove the solinoid w/o removing the manafold? Pardon my ignorance.

crmont · #11 10-10-2004, 06:38 PM

Mike, do you know what the resistance is through a properly working glow plug? (same e300)

Rick Miley · #12 10-10-2004, 08:08 PM

Mike is my brother's name.

The fuel leaks are causing your starting problem. When mine was leaking, it had trouble starting whenever the tank was less than half full. My solution was to either keep the fuel tank full or park nose-down in the driveway.

You can also hold the key in the start position (rather than letting go right away) to crank it a little longer if you expect a difficult start. It also seems to help to hold the accelerator to the floor to pump as much fuel as possible through there. Of course, once it starts to fire, you let up.

As for changing the shut-off valve without removing the manifold, I could probably do it now that I've done it. But then again I'm 6ft tall and weigh 145, so my arms are long and thin. For someone of more "average" size, and for doing it the first time, I recommend removing the manifold. It's something you should learn to do anyway, and it's not really all that hard. My biggest problem was that either the manifold or the EGR valve was not machined properly, so the bolt holes didn't line up. Apparently, the dealer tech didn't really care last time he worked on it, and he stripped the allen head bolt that goes in there. So I had to take the next section of pipe out with the manifold. Not pretty, but I got the job done. Hopefully yours won't be as difficult.

I haven't done any resistance testing on these plugs, but it would seem to be the same as the others posted here. My experience is that these glow plugs seem to last about 40,000 miles. And of course you'll want to replace them all at the same time since the manifold has to come off.

It's really not all that scary, but the dealer seems to think so. As soon as they say "intake manifold" it's ka-ching - another $500. Did you find Lightman's post about the glow plugs?

Rick Miley · #13 10-10-2004, 08:11 PM

Quote:

Originally Posted by crmont

That might then indicate an air leak? (bubbles). Is that o-ring under positive pressure?

That spot is the fuel supply for the injection pump, and yes it is under pressure. After the fuel snakes around through all those plastic lines, one way or another it goes through that little black box to the i.p. It should be all fuel at that point, no air.

crmont · #14 10-10-2004, 10:15 PM

I did find the post about replacing the glow plugs. From a troubleshooting point of view, repairing the fuel leaks before the glow plugs as pertaining to the starting problem. The car has the same starting problem when it is hot so the glow plugs are probably ok. Not to mention the glow plugs have been replaced to some degree by MB in Portland OR. I've gotta get those records!

crmont · #15 10-10-2004, 10:21 PM

The leak at the top of the injector pump has stopped. I do have another leak around the valve somewhere. A drip about every 2 min at idle. It drips on the block and evaporates enough that I have never seen fuel hit the driveway. It's strange that such a little drip would cause the car to stumble. Even when I start it right back up it stumbles. If it sits for an hour it does not stumble.