Well, the other day I started the van and started hearing a metal "tinging" sound. Not always regular, but varied with engine speed and didn't matter if AC was on or off. Due to the sound, it sounded like it couldn't be internal to the engine, and was coming from the belt area. After a quick search showed water pumps tend to fail around the 100k mile mark (113k miles now), I figured it was that. I did get a mechanics stethoscope, but there's no way to get it on the water pump I could see without it hitting the belt. But I listened to the AC compressor and the alternator and it's not them. And put my hand on the water pump pulley and wiggled it and it had play. So definitely the water pump.
Anything else I really should replace when I'm in there? Things that I definitely will be replacing:
- Water pump
- Thermostat
- Thermostat O-ring
- Serpentine belt
I saw mentions of people changing the tensioner or tensioner pulley, idler pulley. Some people said change them, some said it's fine. I'm leaning towards just leaving them for now, money is a bit tight at the moment, and the tensioner costs more than the water pump! Haven't had any issues with belt slippage either.
Sorry, Just saw this I see you are at it already. I was able to do this in about 3 hours without removing the engine mounts (except for the top torque mount) and without jacking the engine. Some are for different years. Mine is a 2013 Limited AWD. Parts I replaced:
Waterpump
idler pulley
tensioner bearings.
https://www.amazon.com/gp/product/B08X6GB3JK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 you need a pair for the idler pulley
serpentine belt
coolant
replacement torque mount
blue locktite
Here are some youtubes to watch.
The tensioner pulley is not sold separate from the tensioner assembly. Aside from it being like $200 it is a total PITA to replace and not necessary. You can remove the pulley and drive out the old bearings which is a double stack of 17x40x12 bearings. Then I just used a 6" vice and some sockets to drive in the replacements stacked. That part took about 10 min. Timken 2 pack is under $20
They key to getting everything out is being able to be patient and rotating the water pump so that it clears obstacles. You need to remove the pulley from the waterpump and then take it off the waterpump once the waterpump is free and can be moved around a bit.
There are two types of bolts on the waterpump. All the big ones are the same length and will not fit in the small holes and all the small ones are the same size as well. It would be smart to place the bolts into the new waterpump as you remove them to keep track of all the bolts and that you have removed all of them.
I had my sienna up on a quickjack. I did not use a jack to move the engine.
The bracket on top of the waterpump has a long bolt in it that gives everyone trouble both taking out and getting in. This is one of those puzzle things that the best I can tell you is that it is possible if you move it into the right position.
There is a bleeder bolt on the back of the engine near the torque mount that you need to open to bleed out the air in the system.
In the end, my water pump was bad, not leaking, fins still in place but you could feel slop in it after removal. My tensioner pulley bearing was also bad which I figured as it was noisy on the stethescope.
Another tip. If you drain the radiator and leave the cap on it will suck the coolant out of the expansion tank. Otherwise you should drain that manually. Open the bleeder on back of engine to get all the coolant out of the engine.
I used pretty standard tools to pull the tensioner back to pull the belt. I loosened the bolts on the pump pully before removing the belt and use the belt in tightening them as well. There are also empty holes on the belt that you could put an allen key into to lock the pulley but the belt worked for me.
