With the vacuum "block" removed I triple checked the manifold for signs of leaks, there is absolutely zero signs of leakage around the manifold. I installed 2 new mani-turbo gaskets when installing the turbos and I even replaced the gaskets once just to be sure. Looking from above and below I can also see no signs of gasses escaping from the gaskets.


The only place I am noticing an exhaust leak is on the crossover arm on the LP turbo. In this collage the arm was cleaned and the carbon you see on it is from a 40 mile drive. I understand there may be a tiny amount of gasses escape from here but to have that much expelled during a short drive seems excessive. Since the exhaust leak noise stops at ~3k this also makes sense that the valve would be included in that.

Moving forward my plan is to stick a Go Pro in the engine bay and hopefully get some footage of the audible exhaust leak corresponding with the movement of the arm, hopefully we can see some visible gasses too. I am smelling gasses in the cabin through the cars ventilation system when it's not on recirculation.


Finally snagged this blank piece from an X5 at the salvage yard.