thatwasbrilliant

I was under the impression it was a 190F because the coolant and oil temp consistently are above 190F but these two thermostats sold at Rockauto are 180F and say OE temperature.

MOTORAD 637180 180 Degree; Assembly; Integrated Housing Thermostat; Includes Thermostat, Housing, and Seal Info
OE Specified Temperature

GATES 34705 180 Degree Integrated Thermostat Housing; Includes Seal Info
OE Temperature

ASE

... just buy Lexus OEM ... saving a rounding error in terms of cost over the thermostat lifetime is not worth the consternation.

thatwasbrilliant

What I am after is determining is the OEM really 190F or 180F.

ASE

... every GX / 4-Runner / Sequoia / FJ Cruiser I have owned consistently run 185-degrees via OBD measure under normal operating conditions.

thatwasbrilliant

my 2023 ran 195 on the recent "normal operating condition trip". So we still don't know yet what the OEM Lexus thermostat opens at.

ASE

... probably starts to open at 90-degrees. 180-degrees sounds low given emission control regulations with the later models. Call Lexus ... the opening start temperature is stamped in the brass body ...

LeX2K

Spec on OE thermostat is 82-95° C. Interpret that how you will.

ColdIron

So does my 2019



I would prefer 180° as that would drop ATF temps by at least 10° but I am concerned temp sensors are tied to various computer settings at the higher temps. Back in the day it was common to get lower setting thermostats to make the engines run cooler, or warmer, you don't see that option much anymore.

If you do go with a 180° and it is actually a 180° please let me know the results. If it works without any adverse side issues count me all in.

Acrad

Revised OEM PN is

160310S010

Same one used in 3UR-FE as well

ColdIron

Thanks for that Acrad. Looking at the reviews for it running a cooler thermostat will cause the check engine light to come on which was my concern so guess we are locked into factory temp range. So might as well go OEM when the need to replace it comes up.

Acrad

Last year I replaced the hoses, clamps, thermostat, belt and fan clutch.

thatwasbrilliant

Can you provide a link to read these reviews?

ColdIron

At 8 years (80-90K miles for me) that is my plan as well except also doing radiator and water pump also. There was a time that it was all sold as a "water side" kit for vehicles and done at ~50K miles. If I get any of the dreaded pink showing up anywhere between now and then will do it at that time.

ColdIron

Acrad

My water pump started leaking on my ‘12 @ 38k miles but it was covered under my factory powertrain warranty back in 2017.

I think I just cracked 86 or 87k miles.