I see that the number 4 injector has lots of build up could it be that it was not popping right if so would this cause a knocking sound?
I plan on putting new nozzles in them and running them on my euro any reason that wouldn't work on the euro? Any problem running/rebuilding the number 4?
I would recommend getting them pop tested either DIY or at a diesel shop. since you have them out it would seem like it would be worth it to know that they are all injecting evenly. As I recall CoyoteStarfish had a pop tester for sale.
Nozzle wear is one thing, but injector balance is another. Again, I'll admit i'm new to diesel, so if i'm off on this anyone is welcome to correct me. I think it would be best to get the new nozzles installed and the go through the calibration / pop testing. If i'm thinking about it correctly, new nozzles will not correct imbalanced injectors, right.
With that said, I haven't done this with mine yet. But it should be coming soon, as I just picked up a parts car this weekend so I now have two of everything i need which makes change over time way quicker. Just got to pull the injectors out on the parts car, get them checked and calibrated, and then swap on to the "good" (read marginally ok, but soon to be good) car. Just ordered a couple intercoolers today, so there should be some news on that subject coming up.
It is correct that replacing the nozzles won't necessarily balance the injectors because the springs wear also. Depending on how tight your budget is and how much pop testing is, you might consider seeing if pop testing with the current nozzles is worth it. If you can swing it, definitely get new nozzles because odds are they are the original nozzles and should be replaced Anyway.
Is there a BMW maintenance period for nozzle replacement or pop testing?
