Held off any work on the 90 as its been getting a fair bit of use in this weather and it was still moving..... but I decided to check that the turbo was at least spinning etc....
....anyway, it soon became obvious what the likely problem was - the actuator arm is attached to the wastegate by a short stud held in place with a spring clip/circlip thing. The arm had just come adrift, so I decided that it would be a simple enough job to take off the manifolds, drop the front of the exhaust etc to get access and get it back on...... and so it proved, circlip was a minor issue but I robbed one from the wifes apple-peeler that was just the right size..... No other drama beside the usual tight bolts etc. Bolted it back up, new gaskets, fired it up.....sounded wonderful.
....then I noticed the oil. The oil all over the place just where I had been lying to bolt up the exhaust, the oil that was now dripping quite nicely, thank-you. All the wrestling with the turbo to get at the back of it, get the exhaust off etc has obviously hastened the demise of the bottom return hose. :-(
Not a stock item at the usual suspects, so I've ordered one from tinternet but it'll not be here before the back end ofd next week. :-(