Looking for advice on what to do next - '08 330D fault

[youngr6]

Looking for some advice please. Car is a 330d M Sport Touring Auto, 2008, it's done around 163,000 miles, my 5th BMW and it's been great, up until late last year. It started to run a little rough when cold starting, just for 10 seconds or so, then it'd run fine. I do a lot of motorway miles, and even after parking up during the day at work, starting in the evening didn't give any rough idling. I put this down to needing a service, and it got a little worse over time, the rough running lasting a bit longer. Fault codes indicated glow plugs, so I had those replaced, then the fault codes showed glow plug controller, so I had that replaced and reprogrammed as well, still no improvement. At this point the garage was suggesting removing the inlet manifold and looking at the swirl flaps and so on, but they were guessing, and suggested I should take it to the main dealer. The main dealer carried out diagnostics, and then advised the glow plugs and controller were at fault (per the fault codes they read), so they replaced them again - no fix. The next steps were to do the expensive pieces.
- replaced the inlet manifold
- drilled out bolts in EGR cooler (snapped when removing manifold);
- de-coked inlet valves;
- replaced crank case pipe and inlet pipe;
- then finally carried out a smooth running test and "Found injector 3 out of spec - suspect glow plug was masking fault with injector".

This was a really poor experience (they never returned calls, didn't keep me updated, rude receptionist on the phone, etc), but that's kind of secondary to my main ask.

At this point, having spent nearly £1900 with the main dealer (on top of the money already spent with my local garage), they quoted me to replace all the injectors (6 x £470, plus labour). The car's worth maybe £5k without faults, so I declined this, and decided to get the single injector sorted independently.

So - back to the local garage, who removed injector #3 and sent it off to a specialist fuel injection company, who would test it, then repair or replace if needed, and return it. I had a call from the garage yesterday - the injector has come back as tested ok - all within spec and no fault or problem with it. So it's been refitted, (car was due an MoT as well, so had that done), but I'm now left with the same fault, and no view on how to resolve.

Before this happened I had a car I really liked, worth £5k; I've now got something that has no private market value, and I'm £2.5k worse off due to the fix attempts.

I'm loathed to go back to the main dealer, and regret paying them to much money for mis-diagnosing - I even raised a complaint at the time with BMW, who just said they'd sent it on to the dealer and they would contact me about it (they didn't).

Any suggestions? I was planning to keep the car another 6 months to a year (before this happened I'd just spent another £1.5k - refurbished the alloys, put new tyres on, and replaced the diversity amp which was failing).

Thanks in advance!

[sprinter11]

Have you done a leak off test on all injectors?

[youngr6]

sprinter11 said:

Have you done a leak off test on all injectors?

Thanks for the reply - I haven't - no - I'm just relying on garages to do the actual work. I'm guessing if I go to the main dealer and ask them to do this, it's going to cost a fair bit again? Is it an obvious next step? If it is, I wonder why the dealer and garage both hadn't done it already?

[Elliot2000]

If it’s only slightly rough and only for a few seconds from cold, is it even worth worrying about? Can you not just run it? And if it is only this- then surely it’s still pretty much worth the 5k or so u imagine it to be?

There is still quite a few other things it could be, and youncould rule out stuff yourself if you were happy to get a bit oily, and it wouldn’t cost you a lot of money, just some time. Once them bits are ruled out, if it’s still the same there is only a few things left it’s likely to be- or you could live with it as it is