I started having tick over issues after running the car hard so a bit of diagnostics, pulling the injector plugs off one by one pointed at no 5. As I had a used good spare in the toolbox today I made the swap. Ist thing I tried was to loosen the injector clamp and run the engine to pop it out. Not a chance, this one was not giving up so out with the eBay slide hammer. I hour of waking, loads of wd40. I finally got it moving. putting sideways / rotational pressure whilst using the slide hammer. Once out, what a mess, the hole was full of hard carbon. I used a shop vac with a 1/2 in tube to get it out. The washer was still in the bottom and that took another 1/2 hour to dislodge. Replacement in, all back together and a test drive confirms all is well again.
I would highly recommend the slide hammer tool, I would still be looking at it if I had not got one just in case.




 2007 TDV8 VSE
2003 TD6 gone.
2002 P38a gone
1999 P38a gone
1997 p38a gone
1993 VSE gone
1992 VSE gone
1966 Series 2a with V8 conversion gone

Look at all that crud!

Out of interest is the EGR blanked?

Jim

Looks like the copper sealing washer has failed hence the carbon up the side from combustion gases. It may have been suffering from lower compression on that cylinder and possibly a misfire if bad enough. The injector may actually be OK although if you had a good spare then it would be prudent to use it like you did.
More common on some engines than others with certain Mercedes being prone to it, google 'injector black death'.
I diagnosed a friends poor running TD5 with the same issue, luckily just needed new sealing washers. If not caught early enough on those then once the copper washer has given up it can then wear the head as well at which point no new washer will seal it.

jim4244 wrote:

Look at all that crud!

Out of interest is the EGR blanked?

Jim