Been there a couple of times now so I'll pick this one up
1. How difficult is it to remove the injectors generally and especially number 5.
2. Is there any safe way to remove 4 and or 5 without dropping the engine/gearbox.
Removing should be fairly straight forward. As for nbr 5 dropping the rear of the engine is the only way....... I have heard however that some people have cut a hole in the bodywork right above the culprit. Then put a plug in or welded/bogged over3. What sort of cost can I expect to pay someone to tackle this job vs buying parts only and doing myself?
When nbr. 5 went on me stuck it in the garage, had all 5 seals replaced as a precaution. Material £15,50 (seals + new strech bolts)- - - - - garage bill £450,004. Any online instructions (I bought the removal tool from Mercedes back when I had the problem with the 220cdi) and would consider trying it myself if it was "straightforward" only for getting the dam things out. My problem was complete loss of power after replacing them in the 220cdi last time and don't want the same problem.
Plenty of info on Jeep forums, every ageing 2.7 CRD has had it.5. Generally when one goes is it the start of the others going over time or is it just pot luck? I'd read somewhere that they cause problems due to be held in by one bolt which stretches over time. (suppose it wouldn't work to just replace this with a new one and tighten it down and not remove the injector?)
I would guess it's pot luck but they have all got a shelf life. It is not because the bolt stretches but because the hot gasses under extreme high pressure eat away at the washer. Just putting in a new bolt will not solve your problem. You need to dismantle, clean, and install new washer + bolt.As far as 'been there a couple of times' : nbr.2 injector went again on me couple of months after fix. This was dealt with under warranty and could have been duff washer or installation fault by my non-jeep garage. Then I had it again and my garage was going to fix it again under warranty (more that one year after the initial fix) were it not for a phone call to the total utter dickheads at Jeep UK that told my mechanic that the engine is shit and he'll be putting washers in until the cowes come home........that was the warranty out of the window as well
I have however got it on good authority that what Jeep UK claims is bollocks and that these engines a capable of stellar mileage.