Changed IP O-Rings, now have clacking... - PeachParts Mercedes-Benz Forum

carver1 · #1 07-14-2007, 09:22 PM

96 E300D. So about a 2 weeks ago, I noticed the smell of diesel when walking around the car. After looking under the hood, I could see diesel dripping from my one of my fuel lines that connects to the Shut-off valve. Since I was going to have to remove the Intake Manifold, i decided that I would change out everything. I ordered new fuel lines, and viton O-Rings.

The job was not as bad as I thought it was going to be, except for getting Banjo bolt O-ring in place. I finally gave up, as I could not get the bolt back in, and just put the old O-ring back on.

Anyway, once I got all the fuel lines, delivery valves, and other O-rings replaced, I decided to start the car before getting the manifold back on. I finally got it started after 2-3 rounds of letting it crank for about 30 sec. It was very loud and stumbled. I thought this was normal, as there may be air moving through the system, so I let it run for a few min, and then shut the car off. I put everything back together, and started it again. This time, there was a very lound distinct clacking noise coming from the engine. It sounds like 1 cyl. Thinking that it would go away if I drove the car, I took it for a 5 min spin. The car was clacking the whole time, and when I come to a stop, it stubles.

I'm wondering if some dirt fell in one of the DV

.. or there is more air in the system??? I do notice that all the lines have fuel in then, except for the line that goes to the top of the pre-filter, but no leaks that I could fine. My lines were black before changing them, so this may be normal.

I'm afraid that I may have to take everything apart tomorrow.

What do you all think?

Thanks

mdisav · #2 07-14-2007, 09:36 PM

I think some dirt or junk from inside the manifold is bouncing around in one of the cylinders. It happened to me once and I had to step on it to get it to shoot out. I am not telling you what to do but that is what happened to me.

nhdoc · #3 07-14-2007, 10:04 PM

Did you us the proper torque on the delivery valves??? Several people have reported problems if they overtightened the DV seals. The important thing is that they be torqued to about 35NM, whether you do the 30-30-35 or just straight 35 procedure doesn't seem to make too much difference but if you make them too tight it can cause troubles.

carver1 · #4 07-14-2007, 10:41 PM

Well, I did do the 30, 30 35 method... BUT I did it in foot-pounds, not NM. Dumb move, I guess. It looks like i over tightened them by 9 f-lbs, or 10MN. I guess I'll take the manifold off again tomorrow, and loosen these up.

There also was a lot of crap from manifold in each of the holes.

nhdoc · #5 07-15-2007, 06:41 AM

Quote:

Originally Posted by carver1

Well, I did do the 30, 30 35 method... BUT I did it in foot-pounds, not NM. Dumb move, I guess. It looks like i over tightened them by 9 f-lbs, or 10MN. I guess I'll take the manifold off again tomorrow, and loosen these up.

There also was a lot of crap from manifold in each of the holes.

Try retorquing the DV seals using the correct units and see if that doesn't clear it up. You can clean out the manifold with any number of solvents if it is thickly coated with gunk, but I doubt that is what is causing the problems you described. Many have used just straight bio-diesel to disolve that crud in the intake.

carver1 · #6 07-15-2007, 09:30 PM

I took the manifold off again today, and torq'd the DV to spec... 35NM. I screwed on the copper bolts on top of the DV just hand tight, then cranked the car till I saw fuel spitting out, then tightened them. I then started the car, and backed off the copper bolts on the injectors till they spit fuel, which was right away, then tightened them.
I still have the clacking when I start the car. I took it out for a 5 min spin, and really got on it. I can see lots of black smoke.. much more than normal, but when I came back, the knock was still there.

I'm a little concerned that I may be damaging something by letting it run with that noise.

I think that my next stop should be a diesel purge, unless anyone else has any ideas.

Just one question. Is it normal to have the fuel to drain back on the fuel line that goes on top of the pre-filter? Since my fuel lines were black before changing them, I'm not sure if this is normal.

Thanks

Bodgit2 · #7 07-15-2007, 09:34 PM

Same thing happened to me when I did my DV o rings on a 96 E300. The IP needed to be rebuilt. The clattering and black smoke was identical for me. Sorry.
Steve

Brian Carlton · #8 07-15-2007, 09:45 PM

Quote:

Originally Posted by Bodgit2

Same thing happened to me when I did my DV o rings on a 96 E300. The IP needed to be rebuilt. The clattering and black smoke was identical for me. Sorry.
Steve

Is it possible that overtorque caused this issue for you.........as well?

I don't see how the procedure can cause damage to the IP unless the DV's were overtorqued in some fashion.

carver1 · #9 07-15-2007, 10:50 PM

Hopefully that will not be the case. How much did a rebuild cost you? When this happened to you, did you over torque your DV?
I did over torque them, as I was going from Foot-Pounds, instead of NM. It was about 10NM more than spec. Is 10 NM going to ruin the IP?

mdisav · #10 07-15-2007, 10:52 PM

If you have black smoke then there is not some piece of carbon in the cylinder. Did you just change the rubber o-rings or the copper crush washers also? Did you take anything else out of the injection pump besides the delivery valve holder? Are all the springs in there and not jammed?

It is normal for the fuel to return a bit in that fuel line.

carver1 · #11 07-16-2007, 12:03 AM

I have grey smoke at idle, but when I took it for a drive, there was black smoke. I changed only the o-rings, and not the crush washers. When replacing the delivery valves, I placed the spring in the middle of the valve, and then carefully put the DV back. I'm not sure how to tell if the spring is jammed.

carver1 · #12 07-26-2007, 08:30 PM

well, I did the diesel purge. I have to say that it was still very clean when finished. Unfortunately, it did not solve the issue. Unless someone has some kind of epiphany of sorts, I'm going to throw in the towel, and see what the pros think.

dave1980_300sd · #13 07-26-2007, 08:52 PM

Not sure if this'd cause your problem, but aren't you always supposed to replace the crush washers as well when doing the delivery valve o-rings? I was searching around for similar info the other day and I think I saw a couple of posts about this, and about problems that could crop up if you didn't do the crush washers as well.

good luck,

dave

oldiesel · #14 07-26-2007, 09:01 PM

do the job over,use new crush washers and correct torque.If it were me i would not reuse the o-rings either.Before you tear into it try loosening the injector lines one at a time and determine which cylinder is making the noise and pay close attention to that delivery valve to see if it all assembled exactly like the others.It seems you caused the problem,with a little patience i bet you can correct it. My $.02 Don

TMAllison · #15 07-26-2007, 11:00 PM

Do it again and use new crush washers and the correct torque.

I dont think you have been cautioned yet not to disturb the valve inself in any way. Is important not to let them fall over, come out or to change their orientation in any way. I believe this was Blodgit2's downfall which necessiated a rebuilt pump.

Next time I do mine I intend to remove the metal lines at the injectors and prime until a bit of fuel is emited from each line in order to ensure no debris or deterioated rubber oring particles get to the injectors. My beleif is that is what caused my noisy idle after replacing them the first time. Two DP's using two cans each 1k miles apart cleared my nailing up. For me, 1k miles is 2 weeks normal commute. Has never run quieter sicnce I've owned it.

My only complaint after doing them is that I cant blow smoke at WOT anymore to shake the tailgaiters.