Just had dealer replace glo-plugs. On return, engine has developed a mis-fire ( puttt, puttt, puttt... ) that improves with warm-up, but doesn't disappear completely. RPM drops of dramatically during sputtering. Wondering if it is a sticky valve lifter. Any suggestions before I try valve cleaner.
Thanks

You can isolate which cylinder is the culprit by loosening the hard injector lines at the injectors, one by one. IIRC, it takes an open end 14mm wrench. You loosen the line just enough to have fuel spurt out and make note of the change in idle - if it gets worse, that's typical, if it doesn't change, you have your troublesome cylinder.

__________________
1982 240D, sold 9/17/2008
1987 300D TurboW124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting

Added the valve cleaner today. Put the ******** recommended fuel injector cleaner in four days ago. Still misfires. White smoke and fluttering. Haven't tried loosening the fuel lines yet, but will this afternoon. If the injector is clogged, what's involved in removing the troublesome injector, cleaning the injector and reinstalling; probable need some fuel return line tubing, don't you think? Thanks for the expertise.

-RAY-

Oh, I see you're in Yorktown, too.

Removing the injectors isn't bad. You need a deep socket for removing the injector body - one that clears the barbs for the return lines. I have a craftsman socket that I bought recently that doesn't clear them all the way. I'll probably go pick up the Mercedes tool and be done with it. The dealer in Hampton (Tysinger Mercedes) seems to have a good parts department. They're open often and have quick turn around for things not in stock.

The injector return line can crack or not seal properly when reinstalling. It's probably quite age dependent.

As to what's involved with cleaning an injector, often the injector body is disassembled, the seats are lapped flat, the nozzle is replaced or cleaned (I'm not sure of the process), and the injector is shimmed to the proper pop pressure (it requires a pop tester - there are prebuilt ones or you could make one yourself). There are also a couple of members here that rebuild injectors. C Sean Watts is one and is in NC (and is quite a nice guy). I'll probably have him do my injectors when I get around to it

I've taken my car to ********, but I still have mixed thoughts about the shop. I'm not sure if they dislike working on older diesels or not. I have plenty of repair records from the shop from the previous owner and not all their prices seem bad (if you want to know what some of the jobs have cost, PM me). What injector cleaner did they recommend BTW?

-Nate

__________________
1982 240D, sold 9/17/2008
1987 300D TurboW124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting

Numerous threads on injector service, the hard part is sorting out the good info from what you don't need.

If it is leaking definitely. If you take it off the injector in question to service it, it's likely you'll crack or tear it. You will also definitely need a new heat shield any time you loosen an injector.

Nozzle cleaning/testing.

__________________
1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

Thank you for the vote of confidence.....you've never met my wife when I'm having a bad day...

__________________
1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

Nate; Released the pressure on all six, and engine stumbled as expected. Also listened to all six injs with screwdriver to ear and all appear to be lifting. Really at this point , I'm thinking a sunk lifter or bad valve. Any hints. -RAY-

If you suspect the lifters, there's a FSM test you can do (Checking hydraulic valve clearance compensating elements)

http://www.ps2cho.net/downloads/MB%20CD/W124/Index/602_603/05Engine.htm

Although the site is for the W124, the engine is described as the OM603. The 603.960 is in the W124 and I believe the SDL has the .961. I'm not sure of the differences...

I'm not sure how to test the valves (the FSM seems to have the tests after the valves are removed), but, perhaps a compression test or leakdown test may prove more useful in figuring out which area to look at. The replacement FSM articles are in the above link.

__________________
1982 240D, sold 9/17/2008
1987 300D TurboW124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting

Thanks Nate; I'll probably give the job to ******** unless your interested in making a few bucks -RAY- 256-5001

It's above my head, let me know how it goes!

__________________
1982 240D, sold 9/17/2008
1987 300D TurboW124.133 - 603.960, 722.317 - Smoke Silver Metallic / Medium Red (702/177), acquired 8/15/2009
262,715 and counting