I'm back with it. £104.99 out of pocket
The mechanic told me that the turbo wasn't sealed at the intake, and further up and as such wasn't even in the correct position. He's had to re drill a hole to fit it properly, such was the substandard state the turbo was left in.
It had leaked oil and would be leaking air/exhaust gases.
The stupid noises and smoking have gone.
With the new manifold and the turbo sealed up, it really flies. Hilarious as it is, I really don't need nor badly desire a car with this level of power so I'd hand on heart say i would not feel shorter changed with a "less powerful car".
Never, since I have owned this car, have I felt it perform the way it did tonight. It is relentlessly quick, biblically fast but in my tours up north, and mooching up and down motorways this level of performance is probably wasted.
And I still am not convinced by 7g but perhaps because my engine was never "quite right" perhaps that has been short changing the transmission which was designed and mapped for the full compliment of power, which blatantly over 38k miles my car has never made. Its much much more responsive, less laggy and I'd say maybe 5-10% more powerful.
Before you all laugh at me, I've never driven or been in a V6 E class other than a remapped one over 2 years ago. I've only driven a C320cdi and breifly been a passanger in Tim Kemps one. I really wouldn't know that mine was slightly less than perfect until now.