When you flush out your coolant or replace your radiator.

The last thing you need is that Thermostat giving a false reading and then... boom!

 

It should be replaced when the coolant is changed.

 

Never have had an original Toyota thermostat to fail.

 

Your scenario may seem the exception but that all depends on your mileage.

 

I think it varies and there is no one right answer.
Mine went out at 165K but on my previous car, it had the original one from the factory with 345K Miles.

 

varies alot. You will noticed if it fails. Usually they tend to get sticky/slow OR get stuck open. You will noticed if they get stuck close as you'll start overheating.

My 04 V6 XLE has a bad thermostat at around 90K. CEL codes were on all the time, but I started to have random CEL at around 80K. My dad's 00 I4 LE had a bad thermostat CEL from around 110K. Both were stuck open or letting the flow too soon as the car would run quite cold.

Usually you'd want to replace them if you do a coolant flush OR if they are several years old. I'd say if your pushing 100K ish on it and you gotta drain the coolant, you can do it. No set guide line really.

 

I think it is time related more than miles related.

 

Mine gave up around 100k miles and 13 years. Replace it if you are in this neighborhood.

 

Not a Camry, but my '04 Corolla with 301K miles has the original thermostat, radiator, and water pump and they're still working fine. I have regularly maintained the cooling system since I got the car at 39K miles and I think this may be the key to the durability of the parts in question. Yes, I should probably replace the T-stat soon just for the sake of avoiding any future headache, and when I do, it'll be a Toyota/Kuzeh T-stat.

 

I guess like others said, it varies.

But given how cheap one is, for example, the Stant 48278 OE-Exact is less than $10 + shipping. I'd just change it every time you change the water pump or radiator. It's one of those while you're at it kind of thing.

 

I'd just change it every time you change the water pump or radiator. It's one of those while you're at it kind of thing.

Yes, I don't disagree. I guess that part of me that wants to see how far I can go on original parts is kicking in. On my kids' cars, I replace the thermostat when I replace the radiator or water pump or stuff like that. Haven't had to do that on my car, so I'm ridin' it out, I guess. My frequent coolant changes have been the key, I think, for the longevity of the thermostat and other components.