I just completed a timing chain and water pump replacement on my 2007 Cooper S. The procedure was performed per the Bentley manual and the car ran great and drove fine for a two miles on the test drive. After two miles of vigorous test drive the car lost boost and went into limp mode on the way home. A minute later the yellow half filled yellow engine light appeared in the tach. I was planning to limp it home with caution, however when I got to a stop sign it shut off on its own and wouldn't restart. After pushing it home to the garage I scanned it with the generic torque app and no codes. The CEL on the speedo is NOT present, just the engine half full yellow warning light appears when it tries to start. When I open the oil cap and have a buddy try to start it, I can see the cams turning over, so it is definitely cracking and not locked up.

I know I need a real BMW scanning tool, not the generic torque app. Going to borrow one from a friend today. Will also take the valve cover off again for sanity check, however I really doubt it is timing chain related as it was running great and there were zero mechanical sounds.

I'm thinking a hose is loose or something else has come disconnected. Sound familiar to anyone? Suggestions to check?

 

Update: Scan returns no codes?!

Everything under the valve cover looks kosher, the cams do turn when it cranks and the chain and guides look to be fine. S

Sometimes it gives the yellow engine light when it is cranking but not always. Tested with a new battery just for kicks, still won't start

Not sure where to go from here? Take it apart and redo the timing again?