Thanks for your replies.
Adam what was your turbo doing prior to its demise or did it just blow up out of the blue?
Mine is making an increasing whining noise that's steadily getting worse.
I was getting a mettalic scraping noise (worse when cold) getting worse over a period of 6 weeks, the VNT vanes were making contact with the housing, I had no whine or smoke .. Or even decreased performance. 98k is good garrett and hks say 75k -80k is around average variable geometry turbo mileage ... Luckily mine was under warranty !
Whine is normally either bearing noise, or a whine like air is escaping so firstly use the squirt bottle and washing liquid trick and spray all the hoses and connections, look for bubbles failing that. Pull the air duct off the front of the turbo (undoing the clip obviously) and check for excessive play in the shaft. Up down left right and spin it if you can and listen for anything untoward any movement will tell you if the bearing is worn and it's a journal type bearing not a ball bearing turbo so it shouldnt move at all and if any not much !
You can only inspect the rest like vanes, shaft ect by stripping it out.
There's a GT15 GT17 GT25 minor rebuild kit available anywhere from about £40, which basically is new bolts, seals, and journal bearing.
A new shaft and turbine is around £80 .... House a compressor it's time for a new turbo and not worth fixing ... Hope this helps !!!