MazdaSpeed3 - Test Engine Serpentine Belt Pulleys

Courtesy: C.T.B.B
Link: http://www.mazdas247.com/forum/show...est-2.3L-Turbo-Engine-Serpentine-Belt-Pulleys

My 07 MS3 has been making a little racket under the hood the last week or two, finally addressed it today. I knew the serpentine belt tensioner pulley bearing was making some noise, sounded like a pop can full of rocks down there if you pressed one end of a stick on the pulley retaining bolt and the other to your ear, was fairly noticeable even with the hood closed at idle. Called my local Mazda dealer who informed me it was not covered under the 60K engine warranty, though I didn't think it would be. Transferred over to parts, pulley is not sold separately from the tensioner, bearing is of course not sold separately from the puller, the tensioner was like $144.00 I think, may have been cost, maybe list, may have been another call I, and not only not in stock, but on national back order with a waiting list of 173 units. Mr Parts Man thought it would be months before he could get one. Mind you, this is a smaller dealer in a town of 15,000 and not a Speed authorized dealer, but I don't believe that would change their ability to order parts for others.

Called the local NAPA and Auto Value stores, nothing listed in catalogs/computers for tensioner or replacement pulley. I knew that my tensioner bearing wasn't going to get me through a few months so my options were shrinking. Pulled the pulley off the tensioner and measured it, 70mm O.D. x 17mm I.D. x 23 mm wide. Checked Dayco buyers guide, guess what the dimensions are for their 89015 pulley? Had it in stock at local Auto Value, number should be easy to cross by any supplier and fits a bunch of other common vehicles, my cost was $14.14 but don't be surprised to pay 18 or 24 or something similar retail. Exact match to OE pulley size wise, just has differently designed support webbing on the plastic portion. Problem solved, except...

Did general check when the belt was off, found the idler pulley had a lot more side to side play than I liked, pulled it and sure enough, bearing is crapping out there too, felt rough spinning in your fingers but wasn't making noise that I knew of, or else had been masked by the noise from the tensioner pulley bearing. NAPA had a listing for the idler pulley at $55.29 but not in stock, and a heck of a lot more than I wanted to pay and I really wanted to get the job done when it was already apart. Pulley wasn't really bad, the bearing was, so cross referenced the number stamped on the bearing, it crossed to a National 203FF, local Auto Value had three of them in stock at cost of $2.97. Pressed out old bearing, pressed in new, perfect fit. Again, don't be surprised to pay a little more retail. NAPA shows 4 different bearing numbers for that cross, all showing different applications and pricing, from $3.29 to $14.99 list.

I never asked Mazda what the price was on the idler or if they had it in stock, but with the price of the tensioner pushing $150 I wouldn't be surprised if the idler is $30 or 40, I figure I got conservatively $160 worth of parts replaced/corrected today for under 20 bucks with no wait for delivery and numbers that should be readily available anywhere. It's a very straightforward job when the car is on a hoist, maybe 30 minutes if you take your time, after doing a couple could probably be done in 10 or less. Tensioner is accessible from right front wheel well with inside splash shield removed, idler not staring you in the face from there but still pretty easy to reach.

Be careful. With the engine running, take a long screwdriver, wooden dowel, what have you, and stick it down alongside the serpentine belt and onto the retaining bolts of the tensioner and idler. Put the other end on the very front of your ear, against the side of your cheek, and listen for the growl. If you're not coordinated enough to do this without hurting yourself, don't attempt it. It could slice off your head in two pieces like a Magic Ginsu Knife and never think twice. Seriously. That screwdriver getting grabbed by the spinning belt will smack you in the face harder than Mike Tyson after you stole his George Foreman Grill. If the noise you're hearing from the engine is in sync with and sounds like that growl noise, grab a couple wrenches (I believe was a 12 mm for tensioner and 10 mm for idler) and a seat and fix em yourself.

Tensioner Pulley: Dayco #89015
Idler Bearing: National #203FF

*If I would have been really on top of it I would have checked the number for the bearing for the tensioner pulley and replaced it instead of the entire pulley, if it's not gone I'll check that number on Monday, probably easier still to find the bearing than the pulley.