Spoke to the AET technician about my turbo.
He says they've never seen carbon deposits of this magnitude, especially since they had double-ringed it a couple of months ago.
They also claim everything's scored and damaged from foreign objects in the oil. Well, if they want money for warranty work, they would say something similar, wouldn't they? Anyway, I give them some benefit of the doubt for the moment
Now...I know that there were no foreign objects in or around the oil, as I cleaned everything myself.
I also know that there was something wrong at the middle section of the turbo, exhaust side, as (at the end) it was dripping oil from there. This indicates extreme oil pressure (which I hadn't) or poor drainage. This I will further investigate.
Poor drainage can be caused by a blocked or kinked pipe (mine was new, of course)
It can be caused by high oil level in the sump, that won't let the turbo return oil flow freely. Not the case here either.
It can be caused by a pressurised sump (by blowby gases and poor crank ventilation). This wasn't the case either, as I had recently investigated all these.
...So WTF can it be?
He proposed substituting the oil return pipe with a transparent one, so you can see if the oil is not flowing and is piling up. Good idea this, I'll definately do it, only way to eliminate this blockage/pressurised-sump scenario.
Due to the extensive oil in the wrong places, the turbine has melted solid with the axle, so they both have to be binned. We arranged on a mutually satisfactory sharing of the costs involved, but this was a warranty job, so happy I'm not
I'll have to take the sump off and check the inside of the oil return for any funny business. The sump gasket needs changing anyway, but still I'm not too happy having to crawl under the damn thing (I have to buy a big trolley jack to lift it enought to get to the middle section of the exhaust) Plus big-@arse axle stands and the whole thing starts getting dangerous after a point, doesn't it?
I intended to have this done by a garage with proper hoist, but now I can't really drive the car with a new turbo and unchecked sump, can I?
If I find the reason behind the smoking, it could well be the case that many more LETs suffer from the same, as the turbo recon did NOTHING at all to fix my smoking. In fact, it made it worse, with them cleaning out the carbon deposits from the exhaust side.
I'll keep ya posted.