Hi Scotty,
At around -20 degrees Celsius my 2018 Toyota Sienna AWD 35k odometer struggles to get up to operating temperature. My wife and I have the heated seats but my kids freeze. We have command started twice so 30 minutes idling then drove 1hr in the city and still the gauge only just started to touch the graduations on the gauge and blow warm but not hot air. I can't plug in where I am so I run synthetic. Its a really low viscosity number so I'm not worried so much about the lubrication of the parts. My start up procedure is as follows:
Above-20 oC I command start once for 15 minute warm up.
Below -20 oC I do this twice for a total of 30 minutes idling
My area is residential so I loaf it at 25 to 30kph and 10% throttle or so till I get to a feeder road then I'll do 50kph with 25%throttle. Once warm I may go as hard as 50% throttle but rarely more. I've learned my lesson from photo radar years ago :). So today I had an appointment the dealership but of course its above 0oC today so it behaved better. Is it possible for a thermostat to lock open in the brutal cold but behave normally when warmer? Last tank we got about 250 kilometers range which is horrendous. Dealership says there is nothing wrong. Years ago I was told the upper rad hose should remain cold as the ambient temperature until the vehicle reaches operating temperature at which time the thermostat opens and that hose will start getting warm. These guys told me they plugged in an it was all good. Do they even teach these kids coming out of vocational schools any practical diagnosis techniques? If this vehicle is operating as it was intended its the first Toyota I've owned that is a fail. I miss my 81 Toyota Celica Supra.
Years ago I was told the upper rad hose should remain cold
It used to be true, but cooling systems have changed for better efficiency.
Thats strange as fuel runs rich till the engine warms up. You would think allowing some to get by would slow warming and increase the time the engine runs rich.
No, bypass engines actually heat up faster now, again for efficiency. But a side effect is less cabin heat until it warms up.
I also find that engines take a long time to warm up while idling. But if you drive it up a hill it happens lickety split.
Could be that you have a fail safe thermostat which sticks in the open position when it fails, thereby not letting the engine warm up for a long time. Possibility?
Thats definately what I thought was happening. Next cold night I'll park my van at the local Toyota beside a brand new Sienna. In the morning I'll get them to start their van and I'll start mine and we will find out once and for all.
So I was able to get Toyota to agree the thermostat was faulty. The faster you go the colder it gets. They said they checked and there isn't a single replacement thermostat in North America. I asked isn't it made in America? They were preping me for a two week wait. I'm sure they will make it right eventually. Thanks for the input everyone.