Hey, so. 

I have a 2009 audi a6 c6 with the 3.0 tfsi caja engine.

The car worked perfectly when i got it. After a week or so of owning it I checked the oil filter to see if the oil was cooked or not. When i fastened the oilfilter again i suddenly got low oil pressure and a chain rattle. 

After another week I did a service under the supercharger where i replaced the thermostat, waterpump, pcv and oilfilter housing. When i put this back together again i still have the low oil pressure and now lots of white smoke in the exhaust.

I am thinking that the problem is with something i have touched, but after again replacing the pcv i dont know whats going on. 

We have done a compression test on the cylinders and they are all good. I do though have sludge in the valvehouse ventilation hoses. 

Any ideas?

Just an idea.

I’d suggest you revisit the oil filter. 
Buy a new one and install it. 
I think it’s probably collapsed or become distorted on the reinstall. Maybe…