I had been noticing what sounded like a vacuum leak lately when driving the BMW. Also, the colder the weather has gotten, the worse the car has been idling in the morning. Sometimes it would even die after starting up. Eventually it lit up the ‘Service Engine Soon’ lite.
After a little inspection, it was found to have two fairly large tears in the intake ‘boot’ – the tubing that guides air from the air filter down to the throttle body.
This item is separated into two separate pieces, and I found both with a great website (RealOEM).
I will be ordering the parts soon, and replacement should be fairly easy.