My OM616 makes what sounds almost like an injector nailing sound when it's cold...the noise goes away once fully warmed up.

I'm wondering what could be causing this? Does this sound point to anything in particular?

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

While I do not know the exact cause for your car..... this type of symptom has been reported before and talked about in the archives.... and in the Factory Shop Manual...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Ok...well I don't know exactly what to search for...and I don't have a factory shop manual.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

id run some diesel purge threw it.

That does sound strange. Best to take another video with the hood up.

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1983 240D 3.0T 4-speed manual, now sold

1989 Subaru GL Wagon 5-speed Touring Edition

Ok, I will try to get another video...but it will have to be tomorrow, as I have already driven the car today and it is warmed up.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

Ok, so I'm almost positive that this is injector nailing. I haven't been able to get a video of a cold start recently due to circumstances. (car is shared) but I drove it this morning, and the nailing is getting worse.

It sounds like rocks rolling around in a coffee can, and is irregular and random. I just replaced the glow plugs and did a valve adjustment with no improvement. Oil pressure is fantastic, and I just did an oil and filter change. Still has decent power and runs smoothly otherwise.

I'm assuming the next step would be to replace the injectors?

The noise goes away once the engine is FULLY warmed up. (at least 15 minutes of driving)

__________________
Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

The noise has gotten slightly worse in 2k miles of driving, and I'm now not so sure that it's nailing...it is now making the noise at ALL times, even when fully warm. The noise sounds almost like what you would call "pinging" in a gasser. It's just audible at highway speeds, not super loud, but enough to make you notice. Like this: tick...tick.....................tickticktick.........tick......tick.........tick.......tickticktickt ick......tick.....etc.

The only thing I have done to try to diagnose this problem is crack the injector lines while idling, and I thought the sound went away when I cracked #1, so I replaced the injector with a known good one I had around. Nope, sound is still exactly the same...can't figure out where exactly it's coming from, but it sounds like combustion noise to me.

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

You might want to have all the injectors pop tested to make sure they all have good spray patterns and pop at the right pressure, or at least all at the same pressure.

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1983 240D 3.0T 4-speed manual, now sold

1989 Subaru GL Wagon 5-speed Touring Edition

If that were my car I would have the Valve cover off immediately for an inspection of the valve train and timing chain. That sounds pretty sporadic to be an injector. IMO...

Check valve adj., inspect chain for pins backing out or missing, check chain guides, etc...

Vacuum pumps can make horrible noises too when they are about to fail. Not a very good video. Maybe open the hood, up the vid. quality and make it shorter?

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AJ

1985 300D (SOLD)

Do you have a really large wood handle screw driver. Use it as a "stetascope" to try to locate that sound. Check that vacuum pump real close also.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I'd put a stethoscope on the vacuum pump. doesn't sound like nailing to me. Too rattley.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Here is a video I took about 10 minutes ago. See if you can spot the knocking/nailing sound. At hwy rpm's they get much faster and more frequent, and almost sounds like "pinging".

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Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

My 300D does pretty much the same thing i have no idea what it is. My injectors are rebuilt, valves are adjusted properly. Has done it since I bought it. But it only does it when cold and when revved above idle.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

How is your idle quality? Mine isn't the best, but it's not as bad as most i've driven.

I guess I'll be pulling the valve cover tomorrow.

__________________
Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles