Hi, My wife's 2008 Mini Cooper Clubman S just started running rough. I checked all the plugs and it looks like cylinder 3 is misfiring as it was the only one that was black. We recently had the excess carbon build-up cleaned out by the dealer about 6 months ago so hopefully it doesn't need it again. I Seafoamed it today but no luck...still misfiring. Thinking this hose might be the culprit. When looking over the engine, I found this hose disconnected on both ends (see pics). Anyone know where this hose goes? It is about 6 inches long. Thanks for your help in advance. -Brian (for some reason, all the photos rotated to the left. Picture them rotated 90 degrees to the right) Hose (about 6 inches long): Found the hose here on the drivers side: Full view of engine:
As Metalman said; it's the vent tube for the automatic transmission. As for the misfire, you should have it looked into by a shop with a dealer level tool. It could be as simple as needing a coil replaced, but I wouldn't start throwing parts at it until you find the true culprit. Try moving the #3 coil pack to cylinder #1 and see if it follows, if so then you have evidence enough to buy a new coil.