The tensioner on my 2015 CX5 Touring went out at 55k. Leaked/chirping with AC and low RPMs. Mazda dealer diagnosed it for me. The comments here made me believe I could replace it myself.
I got it done in about an hour and a half. Jacked up the car, removed the bottom splash panel (10mm). Removed the tension by putting the 17mm wrench on the solid sliver/aluminum protrusion and turned counter clockwise to depress the hydraulic piston of the tensioner. Belt slipped right off pretty easy. This may take two people. I slipped the belt off while the father-in-law held the tensioner back. We did all this with regular sized wrenches.. but the extended wrenches would surely make this easier. Removed the top and bottom bolts with a 12mm wrench. Bottom one was tricky, actually needed to put a pipe on the end the wrench to get sufficient leverage. A ratcheting wrench made the removal easier. Although on the bottom bolt, stop using the ratchet cause you will get the ratchet stuck between the half-removed bolt and the car frame.
Overall, you CAN do this without the extended length wrenches. You PROBABLY want a 2nd set of hands to help. One person under the car, one above. Save yourself the 430$ the dealer quoted. Found the OEM tensioner on ebay for 75 and a new serpentine belt for 22.
I got it done in about an hour and a half. Jacked up the car, removed the bottom splash panel (10mm). Removed the tension by putting the 17mm wrench on the solid sliver/aluminum protrusion and turned counter clockwise to depress the hydraulic piston of the tensioner. Belt slipped right off pretty easy. This may take two people. I slipped the belt off while the father-in-law held the tensioner back. We did all this with regular sized wrenches.. but the extended wrenches would surely make this easier. Removed the top and bottom bolts with a 12mm wrench. Bottom one was tricky, actually needed to put a pipe on the end the wrench to get sufficient leverage. A ratcheting wrench made the removal easier. Although on the bottom bolt, stop using the ratchet cause you will get the ratchet stuck between the half-removed bolt and the car frame.
Overall, you CAN do this without the extended length wrenches. You PROBABLY want a 2nd set of hands to help. One person under the car, one above. Save yourself the 430$ the dealer quoted. Found the OEM tensioner on ebay for 75 and a new serpentine belt for 22.