Injection pump delivery valve seals - PeachParts Mercedes-Benz Forum

ChicagoJones · #1 01-27-2007, 01:53 PM

Hello All,

I've been slowly figuring out why my car still has the "shakes".

Here is what I've done so far.
1) Motor Mounts - No improvment.
2) Diesel Purge -No improvement.
3) Injectors swapped with other used ones in good condition and then swap positions. - No improvement.
4) Diesel Purge again - Slight improvement
5) Changed Both fuel filters - No improvement.
6) New rack dampener bolt - Maybe Slight improvement

Trans mount in good condition, I ordered new engine shocks and I guess I will have to look at the injection pump timing.

But... I was searching on some past Threads and some people mentioned Injection pump delivery valve seals can also cause loping but really can't find an explaination on it. What is this? How do I know it is bad and how do I replace it if it is.

My car shakes and sometimes it makes the air cleaner vibrate even though it has new rubber mounts. I also can hear an occasional ticking or possibly knocking noise coming from the IP if I put a stethoscope on it.

Thanks in advanced!

Hit Man X · #2 01-27-2007, 02:20 PM

I haven't seen 617s with that issue. When the DV seals are bad they leak fuel.

The motor isn't balanced so it will always shake to an extent.

#3 01-27-2007, 02:27 PM

Quote:

Originally Posted by Hit Man X

I haven't seen 617s with that issue. When the DV seals are bad they leak fuel.

The motor isn't balanced so it will always shake to an extent.

When I had a bad (leaky) IP on my 300D it was a little shaky, sorta like one cylinder was weak. A new IP did smooth it out.

Hit Man X · #4 01-27-2007, 02:28 PM

That I can understand, it's misfiring. But he didn't say he had any external leaks. At least not what I saw from the thread.

ChicagoJones · #5 01-27-2007, 02:30 PM

I don't think I have an external leak, I looked all around for it. It does seem like it is misfiring though. The shaking is way more then it used to be.

Hit Man X · #6 01-27-2007, 02:31 PM

Have you checked cam timing? IP timing?

#7 01-27-2007, 02:31 PM

Quote:

Originally Posted by Hit Man X

That I can understand, it's misfiring. But he didn't say he had any external leaks. At least not what I saw from the thread.

Yup, I suspect he has a different issue. I would start with valve adjustment, IP timing, check the timing chain, look for air leaks in the fuel lines, etc. It's usually something simpler (and cheaper) than the IP.

ChicagoJones · #8 01-27-2007, 02:36 PM

Oops I forgotten to mention, I adjusted the valves. But have not checked the timing.. I guess that would be next.

sixto · #9 01-27-2007, 03:12 PM

Have you loosened each line at the injector to see if one cylinder contributes to the shaking more than the others?

Have you checked compression?

Have you had the injectors balanced in terms of opening pressure and spray pattern?

Sixto
93 300SD 3.0

Shorebilly · #10 01-28-2007, 06:57 AM

Quote:

Originally Posted by sixto

Have you loosened each line at the injector to see if one cylinder contributes to the shaking more than the others?

Have you checked compression?

Have you had the injectors balanced in terms of opening pressure and spray pattern?

Sixto
93 300SD 3.0

Not much of a spray pattern tho.....pintle type injectors, spritz a straight shot onto the li'l ball within the pre-combustion chamber......

SB

winmutt · #11 01-28-2007, 09:51 PM

Tis the loping that puts my child to sleep. Couldn't pay me enough money to fix it for the peace and quiet it provides me.

ChicagoJones · #12 01-29-2007, 03:28 AM

I've done the cracking of the injector line thing. Made the engine run rougher on each line opened. I will take your suggestion of doing a compression check and check the balance the injectors.

Anyway, it goes back to my original question. Where is Injector pump delivery valve seals? Or what is the deliverey valve?

Thanks again!

Tymbrymi · #13 01-29-2007, 01:29 PM

Quote:

Originally Posted by ChicagoJones

Anyway, it goes back to my original question. Where is Injector pump delivery valve seals? Or what is the deliverey valve?

http://www.ece.msstate.edu/~jer99/mercedes/BoschHighlights.pdf

Page 18 & 19 talk about delivery valves. All that info is copyright Bosch, and if you would like the info on how to purchase that book let me know and I'll post it. Its a very good read

On the MW pump: whatever the thing is called that the hard high pressure line connects to on the ip, when slowly removing that a spring will fall out. What the spring is pushing against on the IP side of things is the delivery valve, after removing the delivery valve, spring, etc, there is a metal barrel (?) that needs to be removed. Note the orientation. Underneath that barrel is a copper washer(if you try to order one from a WorldPac distributor they will say its a rubber o-ring... its NOT). That is the delivery valve seal..

When doing this keep everything as clean as possible!!!

I have an IP where the delivery valve seal leaks... fuel wells up and looks like you haven't tightened the hard fuel line at the IP. I've replaced the washer, but it still leaks. I think I damaged something when I "tried to fix it" before replacing the washer by tightening the fitting more... ie over torqued it and warped something.

So be forewarned....

If you have no leak it is not your delivery valve seals. The leak may not present itself at idle... so drive around the block, floor it a time or two, and then pop the hood and if there is a leak there will be diesel there.

What is your timing chain stretch? I have seen someone who benefited from advancing their timing to 26BTDC (vs 24) with a stretched chain (still within limits), and one of the improvements was a smoother idle. I can't explain why... but its something for you to try, and should increase the priority of checking the timing on your IP (at which point you'll get real comfortable with the delivery valve on #1 anyway).

As others have said, 95% of the time it is not the injection pump... that being said, there is still that 5%. I have gone through 3 bad IPs on my two SDs ...

Best of luck with it!!

merrycran · #14 05-19-2007, 06:34 AM

Hey guys, I'm in a similar situation -- trying to find out why my 240d seems to be shaking rougher than usual. In past 1.5 years I've replaced the motor mounts, tranny mount, flex disks (both), had chain checked and valves adjusted. I do, however, have what appears to be external leaking from two IP lines (pictured). I have not yet had the IP timing adjusted. Suggestions? And is this something that could be causing heavier-than-normal white smoke at cold start, too?

Stevo · #15 05-19-2007, 10:31 AM

Quote:

Originally Posted by merrycran

however, have what appears to be external leaking from two IP lines (pictured).

If it were D/V seals they would leak at the threads where the D/Vs screw into the IP. Maybe your IP to injector, "hard lines" were cross threaded at some time.