My injectors seem to be making a little noise, they may be tired but I wanted to give them a little servicing. I have used Lubromoly Diesel Purge in my Mercedes for years and it always helps a lot, the old injectors on that thing made it a long time with yearly diesel purges. Anyway, to get the full effect you need to run the car/truck off the purge, you put the return and intake/supply lines into the can and it'll run off that for a few minutes. Does anyone know the orientation of those two lines on these motors?

Here is the stuff I was planning on using:
LIQUI MOLY - Motor Oils, Additives, Car Care - Products - Diesel Purge

thanks a ton

 

Not sure how much you would benefit from this since they are oil driven and as Jim once told me at 26,000 psi there isn't much that will stop up the nozzles. As far as the rest
Of the injector you probably already know clean oil will do them better than anything! As for orientation of the lines you could hook up directly to the fuel pump with a 3/8 hose. As for return it may be easier to just cut the return line in front of the tank to splice a hose on to it for your flush then use a comp fitting or a hose to splice it back together. This way if you decide or for trouble shootin purposes you could always disconnect the return line with ease. I'm not sure of an easier way to tie back into the return line!

 

With the right adaptors, you can tie into the supply and return lines at the front of the engine on the lower driver's side above the crossmember. There are two quick connect fittings there; the larger (3/8") being the supply and smaller (5/16") the return. I assume that you supply your own pressure from the cannister like other fuel injector cleaning systems I've seen. You could also tie in before the pump, as David said, and use only the return at this location.

 

I did think of those but thought it would be a pain. Plus you would have to supply fuel pressure from there with an extra pump or have a suction off the pump in the back and a separate bucket for the return up front. It would work but either way you go the bigger line is the supply up front and you'll need a way to pump at least a 55lb supply of lube to the fuel bowl. At least that's what ford says. It would probably still work with only 30lb. With the oem pump you wont have to worry though.

 

Anything is possible with the time and resources. It just matters how bad do you want to do it. The lines aren't really that bad to access.

 

Thanks for all the info. On the Mercedes it picks it up right out of the can, but on this truck it sounds like it might need some artificial pressure in order to take it up, so perhaps it isn't the best thing to run here. I do have a liter or so of Diesel Kleen, maybe I will just run a really high dose through it to help with the injectors. I'm afraid injector work may be inevitable, but I was really hoping for at least 300k out of the originals (I am at 210k now).

 

I would just run my tank down to almost empty put a couple cans in and run till it starts to fuel starve then shut it off and put a couple gallons of fuel in and go fill it up! I don't see it hurting at all just listen carefully for fuel starvation and shut down right away!
Jim & fat Monyt

 

On my 99 E300 Turbodiesel Mercedes, I will yank the injectors out every 100K for testing. I have never wasted time and effort on the "cleaner in a can" snake oils. What if have found is that sometimes the injectors get a poor spray pattern and this tells me if it can be cleaned or like the last time with the Bosio nozzles, some are just plain worn. I tossed the Bosio and got different nozzles.

Same with the Powerstroke. I took them out at 100 K to test it just for the hell of it and replaced it with single stage shot I injectors. They seemed OK but a little dirty so that is the interval I will use.

Problem with injectors is that they build up GRADUALLY and you can't notice it till it is too late. I do injector cleaning by sending them out every so often with gas vehicles. Next year, I will do it with my Seadoos and the ATV before the start of the season. Never bothered with cleaners. Just testing and cleaning as a PM thing.

 

Usually I don't believe on these kind of things either, but it can get through the fuel pump and rest of the system on those older 617 Mercedes. Mine was smoking like a chimney (black smoke, rough running), and after everything but new injectors it was still having the same problem, but I ran two cans of purge through it and it heaved out some black puff and was fine from that point on; so it is pretty good stuff in my anecdotal experience.

 

But is it all gone or is there some left? My gas corvette ran fine even though one of the injectors had a collapsed filter basket. It showed up on the test and every one of them was a little different. After the cleaning, they were all about the same. I checked them myself a few weeks ago with the neighbor's flow bench just for giggles after work.

 

If you mean smoke, yes it didn't smoke from that point on and ran very well. I pop tested them years later and they were a little tired, but with 260k on them I'd say they were well-worn in, I didn't replace them though becuase I wasn't able to track down some Monarks at the time, just the Bosch India specials I didn't even want to mess with. I think those 617 motors are probably the toughest diesel engines (except for maybe a 616) ever built, great little cold blooded engines for sure.

 

I was talking about the crud that you cleaned off. Is it all gone or is there some remaining? Any stubborn remnants? Are the springs and what not still good and what is the pattern and pop off pressure and volume? All the things a can or two or three of "cleaner in a can" cannot tell you. Since I want certainty, I yank them and have them tested. Especially at a diesel facility I can visit.

 

Well there is only so much detergent can do, but I did get another boat load of miles out of those sprayers so I can't imagine it hurt anything. The spray pattern was a little "tired" at ~260k pop test (out of the car on a bench), but not enough to warrent replacing them with Indian Bosch of unknown quality. But to answer your question, it went from smokey like a locomotive to normally smokey like an old OM617 is supposed to be, those were the symptoms I had and they never resurfaced. I got the Purge advice from peachparts forum and an "old-hand" Mercedes guy in the area here so I figured it was worth a shot, surprising since I'm such a skeptic about the stuff you normall see at Autozone or Napa.

I think my 7.3 injectors are getting a bit weak though unforunately. I am getting a little more noise from them than they used to have so I've been toying with the idea of getting some bigger single-shots and tunes to run them, but I want to milk these things a little longer if I can. That said, the more I read about them the less I think anything like diesel purge will help, they operate in a completely different way than the old 617 injectors and probably much higher PSI.