3.0 diesel vacuum pipes

[Moments]

I had my indy change glow plugs last year - these tend to only last about 150,000 miles on six cylinder BMW diesels, in my experience. While changing all plugs (2 were shot, one was 'lazy') the mechanic noticed a collapsed vacuum pipe on the inlet side and changed this, advising me to have the rest done when possible. So I had the other vacuum pipes replaced, albeit last month. They were all pretty much shot on the inlet side, but the exhaust (turbo) side were surprisingly OK and didn't need changing.
One to watch if you run a diesel X5. The vacuum setup looks complex and collapsed pipes won't do any good. The car is running really well now, so something was probably not right before the changes.