Hello all,

My car was running a little hot (about 200 on highway and 210 in the city), so I decided to tackle the thermostat and coolant.

I found that they had previously used an aftermarket thermostat. I also found a lot of rust and corrosion in the coolant reservoir. Upon further inspection, I realized the tubing for the coolant reservoir was completely filled with rust, and water could not flow through. The coolant itself wasn't terrible, so I hope most of the rust got 'filtered' and trapped in that reservoir.

I implore you guys to check out / clean your reservoir tank and tubing. I would also avoid non-OEM thermostats. After installing the new thermostat with the jiggly-wiggly valve down, the car idles around 192.

Hope this helps someone.

The Toyota thermostats are nicely made, and worth it.

Kuzeh makes the best thermostat for these ;)

Rust is from lack of cooling system maintenance, not coolant brand. The Toy stuff is just low silicates.

If your expansion tank line was clogged then probably the heater cores and radiator aren’t much better.

You should probably flush your system a few times. At least until it stays pretty clear. Then re-install the thermostat and fill with a coolant of your liking.
You might consider back flushing the heater cores.

I also put water wetter in my systems. It’s supposed to help with heat transfer and hot spots. It’s cheap and may do as advertised. My rigs run in the high 180’s most of the time.