Head Gasket or Not Head Gasket

[Munsie]

So I've a bit of an odd one. There are no symptoms, no overheating, no lack of power etc. I do however have Oil in the coolant, whilst no coolant in the oil. Done a block test and either I have a faulty test, or there is no exhaust gasses in the coolant. Have run 3 different tests, using both the reservoir and the expansion tank. 

Have a mishimoto Top mount intercooler and I took that off today and the inside of it and the turbo look clean and fresh. 

So.... does anyone have any suggestions here cause I am scratching my head?