Randyman...
New member
I don't think it's as much a thermostat issue as a software issue? (The 4th & 5th Gens both use 82°c thermostats)
{snip}
The point is that there may be a strategy to why it takes so long to heat up. Though with an aluminum block it shouldn't be as prone to uneven heating as cast iron blocks due to aluminum's nature. Not to mention from an emission's standpoint the ECM would want the vehicle in Closed Loop as soon as possible. Some of our vehicles used "heat switching valves" that essentially closed off the heater core so the engine could warm up faster (though I don't recall the 4th or 5th gen vehicles using these.)
As mentioned above - very nice explanation indeed :yo: Sunk in immediately thanks to the clear presentation.
I recall the old "Thermowax" valves on the throttle-body of my old '87 T4R 22RE (parked in storage awaiting a re-build) - likely a primitive ancestor to where this technology is today on our 1GR-FE Dual-VVTi's.
Makes me appreciate my shivering-ass on the few rare freezing days we see in Houston. I'll take a slower heater-response to give my engine block a stress-free warm-up routine for sure.
All that said - I agree with the OP. My T4R's heater takes F-O-R-E-V-E-R to warm up...
I'm also contemplating adding aftermarket heated seats (SR5 w/Black Leather Upgrade - so I'm hurting more than if I had cloth seats). And I live in Houston for crying out loud!!!
My passengers also repeatedly complain about the lack of heat when cold outside (in HOUSTON!!!) - so it's not just sand in my va-jay-jay talking here :hurt:
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