'21 Sienna 2.5l hybrid 202k mi; PU 0w-20 4.6k mi

[Sienna dude]

Have you asked Toyota about it? Has the coolant thermostat been checked or replaced? Is this a normal issue for this model and year of Toyota engines? One thing I know, which won't solve the problem, on big diesel trucks, tractor trailer semi type truck engines, the coolant temp. should run 200 to 212 degrees f, the engine oil temp should run 20 to 30 degrees over your engine coolant temperature. These numbers, at least on a big diesel engines provide maximum engine life, fuel milage, and performance. What is the coolant temperature reading on that same handheld tool you are showing us the engine oil temperature?

 

[GI_GRIFF]

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ENGINE COOLANT TEMPERATURE, maybe water temperature, or even anti-freeze temperature. Does that meter show coolant temperature? It is definitely not the same as oil temperature. Does that Toyota have an air-cooled engine like some motorcycles or airplanes? In other words, no radiator with coolant in it? We know what the dash water temp looks like, I would like to see what the digital readout says on water temperature, so we can compare the coolant temperature with the oil temperature.

 

[Sienna dude]

ENGINE COOLANT TEMPERATURE, maybe water temperature, or even anti-freeze temperature. Does that meter show coolant temperature? It is definitely not the same as oil temperature. Does that Toyota have an air-cooled engine like some motorcycles or airplanes? In other words, no radiator with coolant in it? We know what the dash water temp looks like, I would like to see what the digital readout says on water temperature, so we can compare the coolant temperature with the oil temperature.

Look again, its there

 

[GI_GRIFF]

ENGINE COOLANT TEMPERATURE, maybe water temperature, or even anti-freeze temperature. Does that meter show coolant temperature? It is definitely not the same as oil temperature. Does that Toyota have an air-cooled engine like some motorcycles or airplanes? In other words, no radiator with coolant in it? We know what the dash water temp looks like, I would like to see what the digital readout says on water temperature, so we can compare the coolant temperature with the oil temperature.

WAIT, I see it! The water temp is only at 172! That is messed up, if the thing has had 10 minutes to warm up, that is messed up. You may need a new thermostat, are you a mechanic? If you replace the thermostat, use genuine Toyota OEM.

 

[Sienna dude]

WAIT, I see it! The water temp is only at 172! That is messed up, if the thing has had 10 minutes to warm up, that is messed up. You may need a new thermostat, are you a mechanic? If you replace the thermostat, use genuine Toyota OEM.

Symptoms of bad thermostat?

 

[Sienna dude]

HPL didn't find anything, I am happy.

 

[GI_GRIFF]

Symptoms of bad thermostat?

Well, I noticed the engine was not even running. And the coolant temperature was actually higher than the oil temperature. This is a hybrid, right? You may need a real Toyota technician to check it out. Have you done that yet? This is above my knowledge level. I have never owned a hybrid myself, really don't want one either. On a normal internal combustion car engine, 172 is a really low operating temperature, and the oil temp should be higher than the water temp. You have a hybrid. Have you had it to Toyota yet?

 

[Sienna dude]

Well, I noticed the engine was not even running. And the coolant temperature was actually higher than the oil temperature. This is a hybrid, right? You may need a real Toyota technician to check it out. Have you done that yet? This is above my knowledge level. I have never owned a hybrid myself, really don't want one either. On a normal internal combustion car engine, 172 is a really low operating temperature, and the oil temp should be higher than the water temp. You have a hybrid. Have you had it to Toyota yet?

My alert history is empty, it's not showing any codes, shouldn't it set a code if there's something wrong with the thermostat? Yes it is hybrid, and I have not been to the dealer for a while. I'm going there next month for a recall and I will discuss it with them

 

[Sienna dude]

I'm about to drive hard and try to raise the oil temperature, stay tuned

 

[GI_GRIFF]

My alert history is empty, it's not showing any codes, shouldn't it set a code if there's something wrong with the thermostat? Yes it is hybrid, and I have not been to the dealer for a while. I'm going there next month for a recall and I will discuss it with them

Well, yes, it shows a lot of fuel dilution in the oil, however, the wear metal numbers look great. Maybe there is nothing wrong with it. About 99% of the car owners in the world don't do engine oil analysis on their personal vehicles. They may all have considerable fuel dilution of their engine oil, complaining that their darn Toyota only made it to 300,000 miles. I would discuss it with the Toyota Service manager, someone a little more informed than the service writer when you get there. Change your oil and filter more often. My Toyota dealer told me every 5000 miles or 6 months, whichever comes first. I have a 2025 Rav4, but it is not a hybrid. We may be getting a little more worked up than necessary.

 

[Sienna dude]

Pedal to the floor in sport mode and this is all I achieved. Once I started driving normally, it dropped to 180 within seconds, and will drop to 170 within a couple of minutes. The thing just wants to chill

 

[Sienna dude]

Well, yes, it shows a lot of fuel dilution in the oil, however, the wear metal numbers look great. Maybe there is nothing wrong with it. About 99% of the car owners in the world don't do engine oil analysis on their personal vehicles. They may all have considerable fuel dilution of their engine oil, complaining that their darn Toyota only made it to 300,000 miles. I would discuss it with the Toyota Service manager, someone a little more informed than the service writer when you get there. Change your oil and filter more often. My Toyota dealer told me every 5000 miles or 6 months, whichever comes first. I have a 2025 Rav4, but it is not a hybrid. We may be getting a little more worked up than necessary.

Speaking of the Rav, the new one is sweet. It will shatter all sale records.

 

[GI_GRIFF]

Speaking of the Rav, the new one is sweet. It will shatter all sale records.

I could have waited, but I didn't want a hybrid. All the new ones are hybrids.

 

[Sienna dude]

I could have waited, but I didn't want a hybrid. All the new ones are hybrids.

Hybrid has saved me a lot of money. I just bought genuine Toyota brake pads and rotors, I should be good till 400k miles lol.

 

[SC Maintenance]

Your showing engine oil temps, not coolant temps on your display.

According to the motor review write up from Toyota-club.net the thermostat moves from 80 to 80C. So it should start opening at 176 and be fully open at 183F. I can confirm this is the range in my Rav4 Ice - its usually running around 180 even when its hot here.

 

[Sienna dude]

Lately I have been forcing engine braking myself rather than wait for the computer. With this habit now my brakes should last even longer.
ZERO brake application here

 

[Sienna dude]

Your showing engine oil temps, not coolant temps on your display.

According to the motor review write up from Toyota-club.net the thermostat moves from 80 to 80C. So it should start opening at 176 and be fully open at 183F. I can confirm this is the range in my Rav4 Ice - its usually running around 180 even when its hot here.

Thanks, 172 and 198

 

[Sienna dude]

I am good folks, I am gonna stop overthinking now.

 

[si1491]

Drove the 2025 Crown Signia today. Has the same engine and hybrid system as you but 0W-8. I extracted the FF at about 1100 miles and put in HPL P+PCEO 0W-8 which has about 1000 miles on it. I used Torque app and here is what I found for engine oil temp and coolant temp.
Driving through town and on the freeway, oil temp fluctuated some but stayed around 175 degF. Oil temp did eventually get up to a max of 185 degF but did not stay there for long. Coolant temp continued to rise until it stabilized between 195-201 degF.

This weekend, I plan to monitor it more when I am driving it.

 

[Sienna dude]

Drove the 2025 Crown Signia today. Has the same engine and hybrid system as you but 0W-8. I extracted the FF at about 1100 miles and put in HPL P+PCEO 0W-8 which has about 1000 miles on it. I used Torque app and here is what I found for engine oil temp and coolant temp.
Driving through town and on the freeway, oil temp fluctuated some but stayed around 175 degF. Oil temp did eventually get up to a max of 185 degF but did not stay there for long. Coolant temp continued to rise until it stabilized between 195-201 degF.

This weekend, I plan to monitor it more when I am driving it.

Do a UOA next and see how bad the fuel is. 5k OCI will get expensive with HPL. Did you confirm your warranty will be fine with HPL? To be honest, you don't need warranty for this engine IMHO, unless you get super unlucky and end up with a lemon.
Also, just so you know, there are 0w16's out there that are right at the max viscosity allowed for 0w8.
Pennzoil 0w16 is right at the max limit of 0w8 which is 7.1. Mobil 1 0w8 is a scary 5(the absolute minimum for 0w8), I would stay away from that lol.