Hi Guys, I am receiving the following issue with my 2013 BMW 640D Grancoupe M Sport. Whilst driving, I start the engine and immediately feel that there is reduced power. The engine sounds noisy however no error codes are displayed on the cars dash. If I pull over, turn the car off and on then...

So Tuesday morning my car will be going in the rolling road, I've just removed and blanked the swirl flaps, cleaned inlet manifold and replaced glow plugs / controller as they needed doing too (can't notice any difference in power btw BUT i cleaned alot of gunk out of the inlet so it's not a...