Videos are really difficult to get a feeling for how the noise conveys in real life. Based on what's in the video, it sounds more like a noisy lifter or lifters than nailing. Nailing is usually a very sharp "rap" noise, literally like someone hitting a hammer on an anvil. The noise in the video sounds more like something that's mechanically sloppy. I had a collapsed lifter on Cyl 6 on my SDL that made an alarming amount of noise at idle when the engine was hot. The 606 uses a similar lifter design, but has 24 of them instead of 12. Noisy lifters are common on the 603, not sure how common it is on a 606.

I'd be concerned with the amount of air in the fuel lines though. Any air is bad, but when you rev the engine in your first link, there's an alarming amount of foam going through your plastic fuel lines. Believe it or not, that could be your only problem. Air can and will cause nailing and injector noise.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

I noticed that, it is just after the prefilter. The prefilter and Orings are all new, all of the lines are new as well and I bypassed the fuel thermostat entirely, it's only when I rev the motor, at idle there is nothing even with a flash light. I did not replace any lifters when I did the head, as they were the original ones. Can they be rebuilt or cleaned?

On second thought I cant be the lifter, because when I ran diesel purge the noise disappeared.

That's the exact same noise as several other posters including myself experienced (search toffee hammer).

In my case the noise was exacerbated by fitting a new stainless steel exhaust, it was only when I swapped out the head it went completely (same injectors).

The head that was removed had only done a few thousand mile after full refurb inc skim, my concern was that I had clipped a valve during fitting.

Once removed I checked each valve for alignment and seating using a dial gauge, all spot on, in fact I could find nothing wrong with the head at all.

My conclusion was that it must have been cam related, i.e hydraulic lifters as these were changed too.

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Did you slacken all four bolts (one at back of pump)?

The bolt will turn a couple of times without doing anything until slack is taken up, pump might need a nudge ti release.

Anti clockwise to advance.

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

I did slacken all 4 bolts and on the back bolt it appears to be at the end of its travel on the arch. As for the head, it is a used head but I kept the valve train, it could be a lifter however when I run Diesel Purge the sound stops entirely so I'm leaning on fuel. With the pump unable to advance any further It would appear it's been removed and installed improperly with no room for adjustment. The car runs flawlessly under load once I touch the throttle the sound is gone, and its quiet on start up, only nails once warm.

This is identical to my previous situation perhaps without the smoke, not sure if my noise video is still up but very similar made whole lot worse with s/s exhaust.

If you have a reliable (mine may have been moved) crank pointer you can check static timing with pump notch.

On the subject of additives, try adding rapeseed oil as this will lower viscosity and change the point of combustion, it can also help seal (briefly) and leaks under diesel, DV's, dribbling injector.

Currently running 100% as temp are in mid 20's c in UK, engine sounds like a petrol motor (slight exaggeration but much improved).

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

If you have a lazy lifter it could be your not getting full combustion or even late hence the mechanical noise, adding a centane booster could help ignition thus eliminating noise..

..only a theory.

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

This is kind of my thinking too. If it was truly injection-related, then adding a cetane booster or vegetable oil should help with the noise. It may not eliminate it entirely, but it should sure reduce it enough to easily notice.

a lifter causing problems can cause an inadequate air charge in the cylinder, weird timing events, or if it's sticking open a hair can cause low compression. All of which can be masked by the RPM being raised.

Add in the air in the IP and you have a recipe for a multiple-cause noise. It's entirely possible that you have injection knock in conjunction with mechanical noise. I'd be focusing HARD on getting rid of that air. When the RPM drops, that air pools in the fuel rack and WILL cause injection noise and can contribute to a rough idle if bad enough.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Well I think I'm just gonna drive it this week and see if things settle, the air has me confused as to where it is entering the system so it's either the prefilter or the line to it. I'm going to also do an oil flush, maybe use an addative to clean out things and help clean out the hydraulic tappers. Thanks for all the advice guys, I'll follow up in a week or two to see if things change.

The 606 fuel lines are a joke with those hokey plastic fittings and O-rings. Why they abandoned the superior banjo fittings is a mystery, probably to save 2˘ per vehicle production cost. If the air is present after the prefilter but not before it, you know where the leak is and need to fix it. Until the air ingress is eliminated entirely (there should be NO air in the fuel system at all), you can expect to have noise, refinement, and/or starting issues.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Well it looks like the air bubbles are coming from the super cheapo pre-filter o-ring setup, so I'm just gonna get an inline filter and bypass it entirely. So that will bypass the fuel heater and the pre-filter, both huge weak points for air intrusion. Just need to figure out how I'm gonna flap the fuel hose to the plastic fuel line/clips. I'm then going to run an engine flush with Liqui Moly Engine Flush to see if it quiets down the noise, and run Luqui Moly 5W-40. I also noticed I have an injector that is leaking there the 2 piece injector housing screws into each other.......rabbit holes I tell you!! (its a very very slow leak, just a small puddle in the injector cup after a month)

Don't tell me it was Valeo..Velco or something, made the same mistake twice tagging onto a larger order, looked the part but total rubbish in terms of fitment.

edit, this one Vaico Fuel FilterProduct Code: 503220240

__________________
David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

I had to look it up, it was a Febi. either way screw that thing! I think barbed wire would seal better than that stupid, complicated, half a**ed design!

Weall I fixed the air leak by bypassing the prefilter and using proper fuel line clamps. The nailing is still there, almost seems louder now! I may have a bad set of injectors (I purchased some Bosio Nozzles off ebay, they came in what appeared to be legitimate packaging and the nozzles appeared new, greazzer did them up for me)....would rather pay to change those then try a lifter, since I just put the head on.