Odd noise coming from engine
 

Hey everyone, wife has a 2010 Mini Cooper S with a rattling/exhaust noise coming from the front area of the engine. Very noticiable when idiling. When driving slowly in drive its loud but the faster it goes the noise seems to go away. But when you slow back down to about 10-15 MPH it comes back. I did a quick google search and people are saying it may be the chain tensioner going out. I thought I would ask everyone here there opinion...Thanx in advance