My 2006 MDX just starting making this weird engine noise that only occurs at idle coming from the left side of the engine. Current mileage 125,000 miles. Timing belt, water pump, alternator, serpentine belt, and tensioners all replaced in 2015 @107,000 miles. Just purchased vehicle as of August 2016 with 114,000 miles. Car was meticulously maintained by original owner following "severe" conditions maintenance schedule with 20 service records from Acura dealership. Car runs outstanding in about every way besides this one annoyance. Just want thoughts and opinions about what the noise could be and if I should have concern. And I would love any maintenance tips to follow to keep her running past the 200k mark. Valves have never been adjusted, would it be a good idea to adjust soon or wait until I start seeing major performance problems? Already did 3x drain n fill on transmission with Valvoline max life and bottle of lube guard red and plan to change fluid at least once a year to keep transmission in it's perfect condition. Also change the oil and filter every 3,750 miles using Mobil 1 full synthetic. I really really really love this car more than any other, and want her to keep her til the wheels fall off LOL! Here is a video of the noise...https://youtu.be/53k0RK3ASsE