Delivery valve internal leak as a cause of nailing? Yes? No? Maybe??? - Page 6 - PeachParts Mercedes-Benz Forum

gmog220d · #76 03-27-2017, 05:00 PM

Nice one D300. Good to hear that you and Maxbumpo are making some progress.

No progress on my end. I've been working hard for the past couple months and have got another couple to go before I get my break. Once I hit break time and am done with some traveling I'll be getting back on the E300.

One thing I do notice since doing the DV seals and spring on #6 is that on cold startup the engine runs wonderfully quiet for a few seconds, and gradually drifts back into the nailing routine.

Diseasel300 · #77 03-27-2017, 06:07 PM

Mine did the same thing. Stone cold start and it would fire up smooth as glass and quiet, then progressively run rougher and nail louder and louder. Was worst ~60-70˚ on the temp gauge (was LOUD!). After it got to operating temp the nailing would settle down some, but was always present and the idle was always "lopey". Get it up above ~1300 RPM and it was smooth as silk and would shut the nailing up.

Injector didn't help, DV seals didn't help, fuel pressure adjustment didn't help, lift pump didn't help, diesel purge didn't help. Changing the DV itself did help, and the recent highway trip finished it off. I replaced the DV on Thursday and have driven the car quite a bit since then and the nailing hasn't returned. The engine is a bit "clattery" until it reaches operating temp, but no more nailing. Once it gets up to 85 and gets nice and toasty, its so quiet you can hear the delivery valves clicking on the IP.

gmog220d · #78 03-27-2017, 10:51 PM

Quote:

Originally Posted by Diseasel300

Mine did the same thing. Stone cold start and it would fire up smooth as glass and quiet, then progressively run rougher and nail louder and louder.

This is good to know.

Quote:

Originally Posted by Diseasel300

its so quiet you can hear the delivery valves clicking on the IP.

Jealous!

I'll probably get into #6 again one weekend coming up. I'll either swap #5 and #6 injectors, or I'll go ahead and pick up a new delivery valve assembly and drop it into #6 position on the IP.

Thanks everyone for chiming in. I never ran into this in my experience with OM61X. On all those I've experienced any time there was a nail it was an injector.

Diseasel300 · #79 03-27-2017, 11:35 PM

The SDL is the first IDI diesel I've worked on. I've helped many friends with their Powerstrokes and Cummins, but not worked on an IDI. It's been a learning experience for sure. Wouldn't say unpleasant, but definitely challenging at times.

The DV I pulled out of Cyl 4 had a certain amount of wear on the sealing faces. Without a magnifying glass, it wasn't even visible, but you could feel it when rotating the 2 halves together. I tried to get a photograph to post to the forum, but couldn't get any of the detail to show up. Not sure where the wear came from as all of the rest of the cylinders seem to be OK. The new (used) DV that went in had a nice smooth sealing surface.

My guess is that there was JUST ENOUGH of a leak to make it nail. Fairly amazing how something so small and minor can cause such a profound issue.

gmog220d · #80 03-31-2017, 10:19 PM

Quote:

Originally Posted by Diseasel300

The SDL is the first IDI diesel I've worked on.

As far as diesel goes I've only worked on Benz IDI!

Quote:

Originally Posted by Diseasel300

The DV I pulled out of Cyl 4 had a certain amount of wear on the sealing faces. Without a magnifying glass, it wasn't even visible, but you could feel it when rotating the 2 halves together. I tried to get a photograph to post to the forum, but couldn't get any of the detail to show up. Not sure where the wear came from as all of the rest of the cylinders seem to be OK. The new (used) DV that went in had a nice smooth sealing surface.

I've got some goodies that lend themselves to photographing things up close. I'll certainly get and post images of whatever I find relevant on my end.

And I do have a small update ('96 E300):

- Purge - No difference.

- 2 stroke oil as an additive - I've been running Echo in the last two tanks and I notice zero difference.

Diseasel300 · #81 03-31-2017, 11:05 PM

Quote:

Originally Posted by gmog220d

And I do have a small update ('96 E300):

- Purge - No difference.

- 2 stroke oil as an additive - I've been running Echo in the last two tanks and I notice zero difference.

Your results match mine. The D/V itself seems to have been my issue. The nailing has not returned yet. I say yet, because I thought I had this licked once before! That car seems to keep me on my toes, every time I think I got something fixed, it seems to have a surprise in store

renaissanceman · #82 04-21-2017, 12:22 PM

Where did you fund the replacement springs? I will be replacing my DV seals soon, and I'd like to get my hands on them to avoid doing this job twice.

Pelican's search system seems to always return thousands of results on every search now...

Diseasel300 · #83 04-21-2017, 01:13 PM

It pays to read the whole thread sometimes. The part numbers, costs, and source were all stated in Reply # 26:

Delivery valve internal leak as a cause of nailing? Yes? No? Maybe???

renaissanceman · #84 04-21-2017, 01:34 PM

Sorry. I thought I had read it completely but must have missed it. Super overwhelming week here.

Maxbumpo · #85 04-21-2017, 02:29 PM

Update on my work. A few days ago I finally had time to install the new Monark nozzle injectors that Greazzer had rebuilt for me. The engine noise is louder now (typical with new nozzles restored to the proper pressure) but I think one cylinder is still nailing. I think I may have to also test the delivery valves now, perhaps one is faulty. I know that I had two injectors messed up, which probably deposited a lot of carbon in those pre-chambers, which may be the source of all the extra noise now. I probably will drive it for awhile, maybe dump some injector cleaner in the tank, see if it will clear up.

I also think I've got the ALDA set too rich, there is more smoke visible in the mirror on hard acceleration than what I'd prefer. MPG is also nothing to brag about, ~23 mpg in town.

Diseasel300 · #86 04-27-2017, 12:56 PM

Thought I'd share an update.

2 for 2 DV swaps eliminating nailing injectors now. I finally broke down and installed the Monark nozzles in my injectors. Had them for over a year now and never installed. I've been running Bosch India nozzles and the smoke under load was getting a little absurd. Pulled the injectors, swapped over to the Monark nozzles and carefully balanced them. 1950PSI +/- 25PSI is where I wound up. Great chatter, beautiful spray pattern, no leakdown.

Threw them in the car and went for a drive. Knock-Knock, Who's there? The Diseasel... Welcome back, Injector knock! Checked Cylinder 4, which has been my problem child and made no difference in the noise, if anything it got LOUDER. Went through the rest of the injectors and found #6 was my nailer. LOUD, LOUD nailing. Pulled the injector, pop test was still perfect. 1950 on the nose, beautiful spray, no "peeing", and no leakdown.

Immediately swapped out the DV. Like the one from #4, there was a light ring of wear on the sealing face, no pitting on this one though. Torqued everything down and went for a drive. BAD results. Nailing was even WORSE (to the point of people turning and looking) and now I had a dead cylinder. Checked and it wasn't #6 that was dead or nailing, it was #5. Apparently when I loosened the hard line at the IP, I forgot that the entire DV holder will twist if the lock ring isn't fastened down.

Torqued #5 back down and hooked everything back up. Now remarkably quiet. No more nailing, and surprisingly, the remainder of the idle shake I had is now gone too. For the first time since I've owned the car, the idle is about on par with a 6 cylinder gas engine. Not silky smooth, but to the point that you no longer notice the engine idling. With the windows up you really struggle to tell it's even running.

For those keeping track, I've had NO luck with injectors solving the nailing, but had 2 out of 2 attempts at DV replacement solving my issues.

I'm starting to wonder if the DVs simply wear out and need replacing after x00K miles? The general consensus always seems to state that the IP never wears out, but I simply haven't had that result. I realize that my engine is a tiny fraction of a percentage of all of the OM603 engines out there, but it certainly hasn't been a 'wear-free' experience.

Sort of off topic - for anyone else reading, if you're considering injector nozzles, the Monark nozzles are a massive step up from the Bosch India nozzles. Easier starting, much quieter idle, and significantly improved acceleration. The black smoke on hard acceleration is also SIGNIFICANTLY less. With the 3.5L IP and the Bosch India nozzles, it got to the point where I could smoke out an intersection if I put my foot down hard. My Bosch India nozzles were all popping ~1900 PSI except for one which was 2200PSI for some reason (they were balanced at 1900-1950). 3 of the 6 had poor spray patterns (very narrow spray) and 1 was leaking down internally. Not good for 1 year and ~2500 miles of use on Pump #2.

Maxbumpo · #87 04-27-2017, 08:34 PM

Can you post some pix showing the DV wear? I beginning to think that is my issue as well, with new Monark nozzles and now worse performance (worse smoke, steady nailing from #3 cylinder). If a visual inspection can confirm the DV is the issue, I'll be more confident about pulling that DV, otherwise I'll be replacing DV's as a troubleshooting method. That's not terrible, I've got an IP to scavenge parts, but time is not on my side.

Diseasel300 · #88 04-27-2017, 09:59 PM

Unfortunately my best camera is an iPhone 6. I have tried and simply cannot get it to take a good enough picture to show the wear to the face on the moving part of the DV. Believe me, I've tried. The parts are so small and the area in question so tiny that I'd need a proper camera with a Macro lens to show what the problem area is. I still have the DV's I pulled, I'll ask around and see if someone has a camera I can borrow.

In the mean time I'll try a description. If you have ever seen the DV out of these engines, it's a large cylinder with a hole bored through the center. The edges of the hole are chamfered. The moving part of the DV has a matching taper on its face that seals against the chamfered edge in the stationary cylindrical part. From what I understand they are lapped against each other to provide a good seal.

The moving part of Cyl 4's DV had a wear ring that looked like a shadow where the 2 pieces meet. One part of it had a tiny area of TINY pits. Not sure if it was a flaw in the material or if it was corrosion, but it was there. Replacing that DV took care of the issues on Cyl 4.

Cyl 6 was a bit more subtle. There was no pitting, but there was a wear ring. Was just barely visible and you could feel it with your fingernail. I can only assume that the nailing showed up with the new injectors since they may behave differently from the old ones. I have no explanation why it wouldn't have been nailing with the old ones, but replacing the DV took care of the nailing on that cylinder as well.

It should be noted that my engine tends to have 1 cylinder with a slightly louder diesel "knock" at idle than the rest, but profoundly different than the nailing which is very piercing in tone, very loud, and metallic sounding and tends to get louder and sharper up until ~1200-1300 RPM when it goes away. Just making sure the diesel "knock" and "nailing" aren't getting mixed up for anyone else reading and following along with our progress and "thinking out loud".

dieselbenz1 · #89 04-27-2017, 10:24 PM

Interesting read so far my knowledge is limited I have read don't touch them because they can be tricky to index back in? Any tricks to removal like does it all come out in one unit and how to reinsert. The only lubrication would be the fuel interesting if that influenced the wear.

Diseasel300 · #90 04-27-2017, 10:36 PM

There are a lot of theories out there regarding the delivery valves, but they're nothing more than a very high pressure check (non-return) valve. The mating surfaces wear into each other over time, which is why they're not supposed to be messed with. On the OM60x series engines, they can simply be lifted out and replaced. The actual pumping element is down below. The pumping elements are what is usually referred to as the part that is "indexed". Screwing that up can ruin your IP, but you'd have to try pretty hard on the pumps the 60x series engines use.

I have no idea why the DV's in this pump have the kind of wear they do. It could be poor fuel, low fuel pressure, poor maintenance, high mileage, who knows. It's a 2nd hand pump and I don't know any of the history on it. The DV's out of the original IP (which had a camshaft bearing grenade) are all fine and they are the ones I've been using.