New Monarks!! Awesome! New knock!?! NO!!!
 

I got my monark injectors nozzles installed (love em!). The engine started up and ran SMOOOOOOTH. Like, chocolate/peanut butter smooth. Very quiet. Very nice.

About 5-6 minutes in to running these new injectors.... TAP TAP TAP TAP TAP TAP TAP..... Oh no!! Quick shut it off!! :eek:

So after I calmed down, I ran the engine again and isolated which cylinder was knocking... I sounded like it was coming from cylinder 5 (or 1... the closest to the firewall). Sure enough, I grabbed the hard injector line with my fingertips and I could FEEL the line sort of tapping in unison with the noise. All of the other injector lines has no discernible vibration.

So I ran a can of purge, hoping it would flush out anything that may have contaminated the line... no luck. Then I pulled the injector and disassembled it; looked fine. I cleaned it out, lubed it up, then reinstalled it only to have the tap return in a matter of seconds.

The tap is hard and clear. I topped off the oil, and purged a little more then drove around the neighborhood for a few minutes. Luckily the tap has now seemed to soften out nearly all the way. It's still there, but it doesn't sound as bad as it did at first.

So the big questions; any suggestions to further smooth out the tap? Is this engine dead!? How much longer does she have, doc? :cry3:

She still has plenty of power, and starts up very easily.

I'm going to avoid running the engine in the mean time... don't want to make it worse....


Which one of you was it that said I should avoid the lovecraft tainted car? Yeah.... about that...... um.... maybe a good call....

The thing that kills me is that for the first 5-6 minutes, the car had be best sounding 617 I'd ever heard! Bummer!!! :mad:

Sounds like nailing. Did you have the injectors pop/pressure/spray tested after the installation of the new nozzles?

Dude, if it's just nailing I will be SOO relieved.

No I didn't pop test them. I installed the monarks on my old car and they did perfectly without pop testing.

Anyone want to pop test and re-shim 1 injector for me? If you're in Houston, maybe I could swing by and buy you lunch or something.

Anyone else support the nailing theory?

Should I make a video of the noise? Maybe that will clear up any discrepancies between nailing and knocking?

not really necessary unless the sound does not subside after pop testing. It is mandatory at this point as RRgrassi suggested.

If anyone can help me out with pop-test and re-shim, please PM me.

if you've already done the work, finding a diesel injection shop nearby is the best bet. By the time you pay for shipping and return shipping for the injectors and the down time... its just not worth it.

Or search for thread on how to make your own pop-tester.

Just curious, when and where did you buy your nozzles. I need a set for mine (serious nailing on #1 cyl), but was under the impression they were on back order.

As your engine warms up the lower pop pressure of that injector is reflected by the earlier combustion. So the preignition knock surfaces.Or grows stronger. If you interchange number one and five injectors the problem should move if the engine is basically in good shape.

Easier to have the injector pop tested. Actually they all should be at least checked. At least number them if you go that route.

If you only swapped the Nozzles it is very easy to get dirt in them during the swap.

Where I used to work we had inside place to pull a vehicle into. Injector changes were done out side and Engines were not cleaned off.
Despite extrememe care on my part 1-3 times a year some tiny piece of dirt (even lint from a Rag will do it) would end up inside of an Injector.
Also at that shop when I cleaned new Injector Nozzles before installation I would occasionaly find small particals/chips if metal in the New Injector Nozzles.

Also whe C Sean Watts was selling the Monarks he always included instructions to clean out the Nozzles before use and dip the parts in Clean Diesel Fuel.

Take a know good Injector from you other car and see if the problem clears up.

Just swapping the new Injector Nozzles for the Old one is a gamble. Swapping the without taking the Injector apart and cleaning it decreases your odds.

First I would substitute the injector or move two on the engine to verify it is the injector. It can be a pump out of calibration on that cylinder as well.

Especially if someone was timing the injection pump sometime and did something they should not have. The suspicion or possibility arises anytime the number one cylinder has issues.

Good point. I've got an extra set of used ones I plan to pop test & check the spray pattern on, then take the pick of the litter & try it in #1 cyl.
Either way I'd like to install new nozzles, these have 192k on them.

Mercedes source dot com

Yeah mine had 193k on them. I think I'll swap them around then test again just to help verify that the issue lies in the injector.

I very thoroughly cleaned the injector body and all the innards with brake cleaner, then lubricated and assembled. I didn't remove the pin from the new nozzle to inspect for debris though; should I do this? I thought I read somewhere that I shouldn't take apart my new nozzles.

according to their instructions you should remove the needle and clean out the parts.

i just got mine too and i'm having them popped tomorrow.