Delivery valve internal leak as a cause of nailing? Yes? No? Maybe??? - Page 5 - PeachParts Mercedes-Benz Forum

Junkman · #61 03-15-2017, 10:44 PM

Quote:

Originally Posted by gmog220d

I wonder how some B90 or B100 would make it run. That stuff ran super quiet in the '73 with OM616.

Anyway, I use Stanadyne lubricity formula, and sometimes a shot of Lucas, in all the diesel I run in order to counter ULSD.

There was a "lubricity" article floating around that concluded B(anything) had more lubricity than ULSD. A quick search should bring it up. I don't know enough about fuel to know whether or not the test methods used mean anything. I used to run Stanadyne because a friend of mine sells diesel parts and gave me a deal. Ultimately, I decided that keeping 2-stroke on hand was easier. Adding any lube seems to be less critical on the Mercedes than the Cummins. Perhaps it's because the electronic IPs have closer tolerances.

gmog220d · #62 03-15-2017, 10:55 PM

Quote:

Originally Posted by Junkman

There was a "lubricity" article floating around that concluded B(anything) had more lubricity than ULSD. A quick search should bring it up. I don't know enough about fuel to know whether or not the test methods used mean anything. I used to run Stanadyne because a friend of mine sells diesel parts and gave me a deal. Ultimately, I decided that keeping 2-stroke on hand was easier. Adding any lube seems to be less critical on the Mercedes than the Cummins. Perhaps it's because the electronic IPs have closer tolerances.

Yep. I've read that article several times.

We were members of a bio coop for a few years. We made good, clean fuel. Drying it was easy in NM. I ran 100% during warm months. The car loved burning it. I loved it too, until all the rubber in the system went to poop. I might run some now as an additive if I had easy access to it.

Maxbumpo · #63 03-16-2017, 08:44 AM

Quote:

Originally Posted by gmog220d

I'll be curious about both your results with new nozzles.

New nozzles have NOT fixed my issue. Installed them last night, and if anything the problem is slightly worse. I was not happy to hear the idle after installing them, it was rougher than before, so I took the car out for an Italian Tune-up, and half an hour of spirited driving later it was not improved.

So I'm considering a compression check and one more DV rebuild. I may also try swapping all the DV's with a used "known good" set.

gmog220d · #64 03-16-2017, 05:08 PM

Too bad about the injectors not solving the problem. Please do keep us informed as you work through it.

Somewhere in my readings I came across the idea that a weak lift pump could cause issues with nailing in OM60X engines. Could a lift pump be weak at idle and lower RPMs but fine with more RPMs? Seems like weak lift pump symptoms are the other way around - fine at idle and low RPMs but starved with higher revs. The '96 will downshift, throw out a quick cloud of black smoke, and get going pretty quickly when I mash the pedal down at low highway speeds. It doesn't give me the sense that the IP is struggling for fuel. Curious if anyone else has thought about this possible link.

Diseasel300 · #65 03-16-2017, 06:12 PM

X2 on the nozzles not solving the problem.

Took the injector out of Cyl 4 and rebuilt one of my spares with a new Monark nozzle. Pop tested at 2050 PSI just like the other 5 and has a beautiful spray pattern. No peeing and great "chatter". Almost no bleed down on the pop tester either. Installed a new heat shield when I installed the injector and............it's even LOUDER! WTF!

Silver lining - it DID solve my shaky idle. The Bosch-India injector that was in there would piddle and hang up when doing the chatter test. The shaky idle was more irritating than the loud nailing, but now that the shaking is gone the nailing is now Problem #1.

Next step - swap out the delivery valve on Cyl 4. I have a set of 6 from the original IP. The nailing on my car is very definitely confined to Cyl 4. Crack that injector line and you can barely tell the engine is running. Tighten it back up and knock knock knock...now even louder than before

spock505 · #66 03-17-2017, 06:31 AM

Quote:

Originally Posted by gmog220d

I wonder how some B90 or B100 would make it run. That stuff ran super quiet in the '73 with OM616.

Anyway, I use Stanadyne lubricity formula, and sometimes a shot of Lucas, in all the diesel I run in order to counter ULSD.

A while back, but some good info.

Misfuel then two stroke - Mercedes-Benz Owners' Forums

Adding 2 stroke oil to diesel tank - read this - The Brick-yard - Page 1

Maxbumpo · #67 03-17-2017, 10:51 AM

Quote:

Originally Posted by Maxbumpo

New nozzles have NOT fixed my issue.

Update: due to a miscommunication between Greazzer and I, he set the pressures at 115 bar vice 135, so the jury is still out until I get that fixed. Planning to pull them this weekend and send them back for correction.

Lesson learned: A breakdown in communication is usually the root cause or major contributor to the failure of any human endeavor.

Maxbumpo · #68 03-17-2017, 10:54 AM

Quote:

Originally Posted by Diseasel300

X2 on the nozzles not solving the problem.

Took the injector out of Cyl 4 and rebuilt one of my spares with a new Monark nozzle. Pop tested at 2050 PSI just like the other 5 and has a beautiful spray pattern. No peeing and great "chatter". Almost no bleed down on the pop tester either. Installed a new heat shield when I installed the injector and............it's even LOUDER! WTF!

Don't move to quickly, excess carbon build-up in the pre-chamber from a faulty injector may be what you've got going on now. If you're patient, drive it for a few weeks and see if it improves. If you're not, diesel purge treatment straight from the can.

My problem would always clear up with a diesel purge treatment, but return over the next few weeks.

Maxbumpo · #69 03-17-2017, 10:58 AM

Quote:

Originally Posted by Maxbumpo

New nozzles have NOT fixed my issue. Installed them last night, and if anything the problem is slightly worse.

More info: I may need to find a new mechanic! When I pulled the injectors, I found that the previous guy had FAILED to install heat shields under #1 and #2! Have to keep a closer eye on him...

I strongly suspect that this is the issue I've been battling all along. I'll bet that the lack of heat shields cooked both those injectors, probably baking fuel in the nozzle tips which ruined the spray pattern.

spock505 · #70 03-17-2017, 11:06 AM

Quote:

Originally Posted by Maxbumpo

Update: due to a miscommunication between Greazzer and I, he set the pressures at 115 bar vice 135, so the jury is still out until I get that fixed. Planning to pull them this weekend and send them back for correction.

Lesson learned: A breakdown in communication is usually the root cause or major contributor to the failure of any human endeavor.

115 bar is the correct pressure fr both turbo and n/a, see earlier posts/threads.

Maxbumpo · #71 03-17-2017, 01:54 PM

Quote:

Originally Posted by spock505

115 bar is the correct pressure fr both turbo and n/a, see earlier posts/threads.

Not for my car with an OM603. FSM procedure 07.1-6750 says a new nozzle should be 135 - 145 bar, lower limit for used nozzle is 130 bar.

spock505 · #72 03-17-2017, 02:16 PM

..ahh sorry, i assumed it related to the 606 engine.

This might come in useful for 606 nozzle pressures although US spec may vary due to emissions.

W210 v W124 injectors

Diseasel300 · #73 03-17-2017, 08:13 PM

Quote:

Originally Posted by Maxbumpo

Don't move to quickly, excess carbon build-up in the pre-chamber from a faulty injector may be what you've got going on now. If you're patient, drive it for a few weeks and see if it improves. If you're not, diesel purge treatment straight from the can.

My problem would always clear up with a diesel purge treatment, but return over the next few weeks.

This one will go nearly silent when on straight diesel purge. As soon as it's back on diesel, klack klack klack...

The new injector has made the noise MUCH louder than before, but ironically it's gone sooner. Usually by 1100 RPM the noise is completely gone. Annoying.

I'll be driving the snot out of the car for the next several days. I can't do anything to it until I get the DV seals anyway. Next step though - swap out the DV on Cyl 4.

Diseasel300 · #74 03-23-2017, 06:51 PM

Quickie update - The replacement injector with the Monark nozzle was driving me UP THE WALL with the amount of noise it was making. Swapped the Bosch India nozzle back in after cleaning it up and rebuilding it to stop the incontinence about 4 days ago. Back to Square One with the nailing and shaking idle.

Parts came in today to swap out the DV on Cyl 4. Pulled the best DV out of my parts IP and the best DV holder out of the same IP. Cleaned both up well with parts cleaner and swapped them in.

I'm pleased to report that the shaking idle is now gone and the nailing is all but gone as well! The diesel "knock" on Cyl 4 is still ever so slightly louder than the rest of the cylinders, but the nailing is gone. Car was so quiet on the test drive that I thought it stalled twice. We'll see if it holds up, but the DV itself seems to have been the culprit here.

Maxbumpo · #75 03-24-2017, 09:05 AM

Excellent! Good work!

I've cleaned up and re-installed my old injectors while waiting for the re-do by Greazzer, and my knocking is entirely gone, but I still have a very rough cold idle which I think will probably clear up with the new Monark nozzles.