My 2006 Acura MDX just starting making this rattling sort of noise on the belt side of the engine. Very intermittent of when it occurs mostly after the car starts to warm up you will hear it. Started out only occurring at idle but now can be heard more by fluctuating throttle. This may be unrelated but eversince this noise started the car has only been averaging 12.9mpg when it usually averages 15-16 and I only ever use 93 octane from shell stations. The car has 125,000miles. As of 2015 the timing belt, serpentine belt, water pump, tensioners, and alternator were all done. Any help would be greatly appreciated!!! Thx. Here are two videos of the noise...https://youtu.be/UTDjhYwIO9A
https://youtu.be/53k0RK3ASsE
https://youtu.be/53k0RK3ASsE