I mentioned earlier that my car had a bit of a performance upgrade by Corolla standards, with the 2.4 litre engine. This engine was also used in some Camry models, the Matrix and the Pontiac Vibe in the years leading up to 2011, and probably wasn't really designed with the Corolla in mind. What this means is that the engine to body clearances are pretty tight. In fact, so tight that the only way to remove the pivot/mount bolt from the tensioner is to jack the engine up several inches until the bolt head just clears the body metal.
Fortunately nothing further needed to be removed in order to raise it up.
With the engine up, replacing the tensioner is now possible. I could also see the area I was working in for the first time. In the photos you might get some idea how hard the mounting bolt is to reach (the lower one at the bottom of the spring is easy to get at from underneath. When the belt is installed, it runs from the power steering pulley on the left to the alternator pulley on the right. This is the longest unsupported run, and effectively hides everything underneath it. By now I had also removed the engine side of the mount for more clearance.
The water pump pulley had some black build up which appears to be rubber transfer from the old belt. I removed the material, gave it a gentle shine with some 400 or so grit emery and cleaned it with degreaser before moving on.
Now it's just a matter of routing the new belt, lowering the engine and buttoning everything back up. Ummmm...rightttt....
The alternator has a flange on each side of the pulley and is not the recommended "last pulley" to get the belt onto. In one video, they put it on the tensioner pulley last which also turned out to not be simple due to access and the aforementioned ratchet handle size. It's diameter left precious little space to slip the belt into place. It turns out that the ideal final pulley is the smooth water pump pulley right beside the tensioner pulley.
What a PITA, but the parts were now installed but the belt seemed to be excessively loose despite all the numbers showing as being correct for the car. With nothing to compare it against, I proceeded to lower the engine, install the engine mount and start the car. All seemed to be operating properly but that belt was sure flapping around. My retired Toyota tech buddy confirmed this wasn't right.
The part number on the belt was PK1910, and another compatible belt was PK1907 which had a slightly smaller outer circumference. So I picked up the new belt and I also decided I was tired of messing around with the wrong tool for moving the tensioner. I picked up the proper "Serpentine Belt Tool Kit" aka two piece flat bar assembly. It came with four sockets but of course the biggest one in the kit was 18mm. My fitting is 19mm. But I just needed the tool itself, really. What a difference the right tool for the job makes.
Back home, I swapped to the shorter belt. Starting to get pretty adept at routing the belt and getting it past the tighter clearances by now! Damn thing was still too loose...better, but still loose. And the engine was now making what sounded like an intermittent metallic ticking sound from that area. Taking a video of the belt running, I could see that top run flexing and twisting over 45 degrees from flat and concluded the ticking was the sound of the belt contacting engine somewhere.
At this point, I swapped back to the original worn belt to see how much tension it had, then swapped each of the two new belts back on for comparison. The shorter belt seemed pretty consistent with the original but was still too loose.