Normal Operating Temperature? (LC200 after radiator replace)

[baggar11]

Mine hovers right around 200F. Here's a shot of me pulling a 10k lb trailer, going up a pass in 2nd gear in roughly 100F ambient temps.

 

[bloc]

I could be wrong but the fan clutch is largely only engage at idle and low speeds. I believe it disengages at highway speeds.

The thermo clock spring on the front of it causes it to engage whenever needed, and this could very well be on the freeway if the vehicle is producing a bunch of horsepower, like towing a large trailer. 75mph of air into the front grille is a lot, but so is the thermal load of a sustained 200-300hp. And ultimately our grille openings are pretty small. Similar to, though bigger than, the 80. And speaking of..

A lot of the heat related issues on the 80-series were on the freeway and specifically traced to the fan clutch either engaging too late, or not strongly enough. The engagement temp can be adjusted internally, the force with which it does is adjusted via fluid volume and viscosity. Pretty interesting, you can get different viscosity fluids for those, direct from toyota. IMO the primary reason we in the 200-world don't mess with this is it's just not needed because they designed it well from the factory. But the fan clutch is a wear item, the fluid will eventually lose viscosity due to shear, and at some unspecified point it should be replaced or rehabbed.

I will say.. if my truck is any indicator, the bearing supporting the fan will go out before the clutch does.

 

[04UZJ100]

Pretty normal from what I've seen in my own dashboard. The cooling system is pretty stable and robust.

I've seen a max of 203*F towing a large camper on that same stretch to Vegas on the 15fwy.

I don't think the clutch is a concern on these vehicles even into higher mileage. Never saw much of anyone changing them on the 100-series.

I could be wrong but the fan clutch is largely only engage at idle and low speeds. I believe it disengages at highway speeds.

215k on my 2UZ and I replaced the clutch and fan bracket (along with all other rotating bits) when I did a timing belt a few weeks ago. Engine is noticeably quieter from the front. A few bearings were on their way out. As Toyotas do, they were failing gracefully as they had been making noise for a few years and 25k ish miles. All OEM as always BTW.