I had five glow plug errors and a controller error on one plug, so I bit the bullet and changed everything! It's a totally doable diy job, but very fiddly, there are lots of layers to take off before you reach the glow plugs. Both air boxes, air intake manifold etc. I also had to disconnect the coolant hose from the cylinder head to get the controller out. Lots of generic videos on you tube for E60 cars to give the general gist. There are tales of this taking two hours, I would pay good money to watch someone take two hours on the 3.0sd like mine, more like four-five, but I'm methodical. All faults cleared and run for 20mls to checkout any issues, thankfully there were none. I'm happy to offer any advise if anyone need some help or encouragement. Cheers.
