Nailing, or something else?
 

Well I have been running a two tank WVO system for about 15K miles with no problems at all. The oil is always around 175*F before I switch over from diesel.

Over the past 5K miles I have developed a "nailing" type noise. It only happens when the car is warmed up, doesnt matter if it is running on diesel or WVO.

I orginally thought that it was just a screwed up injecter, until I cracked each injector line one at a time and the noise never went away. Maybe I have two injectors bad? not sure?

The noise only happens at idle (around 600rpm) and totally disappears at 900-1000rpms ....

Check the video to hear it ...

NAILING VIDEO

I would pull the injectors and have them tested. VO is known to coke the injector tips. I'd run biodiesel instead of VO, but that's just me.

I have pulled all the injectors out and taken them apart and cleaned the hell out of them. Could it be that they are just worn out?

Can you isolate it down to one cylinder by cracking the fuel lines? just unscrew the steel line from the injector while running - the cylinder will stop firing. if its the nailing cylinder the nailing will go away.

When you isolate it down to one cylinder, swap the injector with another cylinder. if the nailing follows the injector to the other cylinder its the injector. if not, its something else. maybe the prechamber etc.

thats the next step.

it would also be good to have your injectors professionally pop tested and spray pattern checked. its cheap or free at a bosch service shop (if you have one nearby). just cleaning them doesnt mean they are working right.

I have cracked each line ... still rapping ... maybe it is two cylinders?

they probably were the originals and needed a rebuild ( new nozzles and pop test done).

if you cleaned them and reset the pop pressure properly they will be fine. Members have shown that freshly rebuilt injectors nail for a few hundred miles while they get broken in again..

Does anyone know where I can buy just the nozzle and the pin for the injector?

Your options:

Cheapest, slowest route: get them pop tested, go from there (near free)
Mid grade: Buy new Bosch India injectors, questionable quality ($150)
High mid grade: Buy Bosio nozzles and have them professionally rebuilt ($300)
Premium: Buy NOS Bosch nozzles, have them professionally rebuilt ($400)

As having just been through this, my advice is get them pop/spray tested first to verify that they are indeed your problem and not something else.

Then you can choose what route to take. I chose Premium because thats how I am, and the nozzles had 200k miles/ 25 years on them. I was also convinced it was my injectors causing issues because I could crack a single one and nailing went away.

dd

this should help you on the right track
http://dieselgiant.com/mercedesinjectornozzlereplace.htm

What's NOS? How about just having them pop tested (after cleaning) and then replacing only the nozzles with new Bosch ones as necessary? That's what I would do. The nozzles themselves are not terribly expensive, something like $30 a piece. Usually you can reuse the rest of the injector.

When cracking the injectors, did any of them cause less of a problem? For instance you crack one and the engine stumbles. Did any of them stumble less?