I have a stock twin Supra automatic that is original with around 50k miles. It's originally JDM but has been coverted to LHD. I have noticed strange behavior with the temp and the car starts to over heat on these occasions:
1. Driving on a freeway the temp is fine, but when coming off the freeway and I stop on the intersection, the temps start to rise and then drop back after a while. I think the stock secondary fan comes on every time it starts to over heat.
2. When I park the car after a drive and shut the engine off and leave the key on so I can monitor the temp, the temp starts to rise and the fan kicks in.
3. When I do a burnout, the temp starts to rise quite fast.
So in normal driving the temps are fine, but on those three occasions, the temps rise, but it never goes so bad it boils the fluid.
So far I've changed the thermostat (OEM) and put a stock TRD radiator cap. These did not help. I also tried to bleed the system with the front end lifted.
Stock viscous fan, I'll make sure it's working but I'm pretty sure it is and I'm in the impression if these break, they go solid. I've had that happen once.
Stock radiator with 50k miles.
Car in question: