'07 cooper s wont start after loose tensioner. Timing?
My roommate has a '07 cooper s, and it had started rattling and sounding like a big diesel on cold start up until the revs got higher. Diagnostics said it was the knock sensor, but from what I read, the computer would compensate and wasn't an urgent issue. After reading, it looks 99% like it was the timing chain tensioner.
After driving to work, she went to leave and the car wouldn't start. It turns over, and occasionally sounds like it is trying to fire. I told her to stop trying to start it. Anyways, a mobile mechanic looked at it real quick, like under 5 mins and said it was the timing belt, they wear down and tear and break. Obviously he was an idiot, as they don't have rubber belts, but after discovering that it was a tensioner issue, I feel like it is the timing chain. Perhaps is slipped or the tensioner got too loose. I mean, she got to work fine, it just wouldn't start at the end of the day.
If anyone can help me diagnose it, that would be awesome, it is stuck miles from here, so I need to go look at it, but would like to know what I am looking for, could it be just the tensioner? How would I verify the chain? I have worked on my own BMWs in the past. just basic stuff, never touched a mini but I can figure my way around pretty quickly with some guidance.
Other things to note, before it died, it was getting very poor gas mileage, and on cold start, or while at an idle, it would die, just sounded fine at higher revs. Oh, I think the other diagnostic code after the rattling was something like cam shaft position sensor? sounded like that?
So, I am on a very very tight budget and she has to be able to get to work, literally started work last week. Where do I start?