When starting the van and sat stationary, there was a smell of diesel fumes in the cab. A quick look under the bonnet revealed the suspected culprit of a cracked exhaust manifold.
There was plenty of visible soot around cylinder number 5.
So after some online research, the VW parts bill was over £1000!
I was then suggested to look at Darkside Developments, as they do a cast iron kit which is a direct replacement for the stock VW part. (And wont crack after a few thousand miles - thanks VW)
I gave Darkside a call to just double check a few things and place the order, and a day later the kit arrived. I have to say, I'm really impressed with it, the manifold is of excellent quality, and came with all the necessary gaskets, bolts, nuts and new studs.
So this weekend with assistance from my brother-in-law, we set about taking the old one off, and getting the new one installed.
So as for the parts, its out with the old and in with the new. Upon inspection after removing the old manifold, it was actually cracked around cylinders, 1,2,3 and 5.
It's made a huge difference, the boost seems to kick in sooner, the engine is quieter, and certainly more torquey. It's also nice to not have to turn the blowers off each time I start up or stand still in the van.
So if you've got one of the 5 cylinder AXD/AXE engines in your van, I'd really recommend the Darkside Development kit.