Another noisy 603 clacking that I'm trying to determine...

[87tdwagen]

Hey all,
It's been a while since my last posting...I would like your opinions on my clacking OM603. I've been chasing down so many ticks tacks and clacks that I can't seem to tell what's normal anymore or not.

In any event I have a a clack that occurs at idle 650 to around 1000 rpm where it either goes away or the rest of the noise masks it. I've probed from injector to injector and at the pressure valves and can't discern where its coming from. I just replaced the seals and o-rings on the IP due to a minor leak at #5, corrected that, but the clack persists. This has been on going for a long while and still the clack is there. To eliminate the general condition here is what has been done so far over time:
1 Rebuilt the injectors added bosio nozzles took them to a diesel shop and had them balanced at 135 pop tested etc.
2 replaced the #6 line due to a small crack at the IP side of the flange.
3 Pressure valves, new copper seals and viton O-rings, did not disturb anything inside the IP, actually mine came out super easy and R&R was easy. torqued to FSM specs.
4 have run numerous purges over the years and sounds like a Singer then...clacks afterwards on diesel
5 New fuel filters 2 weeks ago

Overall she's in good running shape and my clacking is relatively minor in the larger scheme of things.

What has not been done and IMO may be a cause for the noise is:
1 Re-balance injectors after bedding in. From what I've read here bedding in can throw the pressures of by 2-3 in each injector.

2 Compression test (I have a minor oil leak at #1 bottom corner of the head and timing cover, known weakness) so #1 could be lower in compression than the other 5. Time for a new head gasket though I dread the workload.

3 Have not checked the lifters, could be a tick, but I can't tell anymore

I have an mpeg linked, let me know if the sound gives you some idea of what I should trouble shoot next. Ideas and suggestions always welcomed
TIA
Bill

http://s89.photobucket.com/albums/k238/75coupered/Benze/?action=view&current=PIC_0009.flv