2017 tacoma not getting up to temp..

Honestly I think I'm just going to see what happens tomorrow and Sunday then I'll force it to temp before my long drive to sub zero SD on Monday. I'm not worried at all about damaging something, this actually isn't really to big of a deal to me, I'm just really wondering what's going on being that it has warmed up in -30 before just fine lol

 

Did you at anypoint get the ac not blowing cold TSB? the one where they install a extra fan on the front of the radiator?
- If they did, turn off the ac button and that fan will shut off and the truck will get up to temp a little better

 

I live near the border of nw ct and ma., its been cold but not quite -14. Ever since winter began my 2020 v6 has been cool blooded taking quite a bit of time to throw any heat. My 2001 4.7 v8 tundra would heat the cab in minutes when that cold. Even the temp gauge on this tacoma reads sort of weird. It comes up to normal mid way when driving normal, but falls to 1/3 way when sitting at idle at a traffic light, or in your driveway. I still get the normal amount of heat coming out though. I'm starting to wonder if a stuck, or sticky fan clutch might be the cause of this.

 

The ECU can actually heat up the thermostat to cause it to open earlier (and further) when it wants...

I believe it only activates when the engine thinks it is above 194F. If there is anything wrong with that system (electrically), I am pretty sure it will throw a code as the ECU will detect that something isnt as it wants it. The ECU grounds the ETM- side to power the thermostat heater.

I wonder if it COULD be an issue with temp sensor.

 

I'm also starting to lean towards a problematic temp sensor, or possibly gauge. OP, you may find it helpful to get an infrared thermometer, and start shooting certain areas of the cooling system. You could put a dot with a paint pen, on certain items/places, like before and after the thermostat, upper radiator hose, lower hose, ect. The dot will help make sure you're shooting the exact same place every time. Start monitoring those few places when the truck is at full operating temp, then see what they are at when the gauge shows lower than normal. If the thermostat housing shows the same temp on the gun, all of the time, but the gauge is giving different info, then you can pretty much rule out the actual operating temp being faulty.

I recommend a dot, because in my experience, changing the location that you are checking, even slightly, can give a much different reading.

 

I am also in Colorado with a 2017 and it is taking much longer to get to temp than normal but drivability seems unaffected. Plenty of heat out of the ducts and it feels normal. During my 15 min commute it never goes to the center like it normally does. With all the aluminum in these engines and radiator I think they are just more susceptible to slight variation in extreme cold.

 

After a 4-5 hour drive, no way. Hell, even the worst car in history should be at normal temp in less than 20 minutes. OP has a problem. It's either a intermittent faulty thermostat, trapped air, or faulty electrical component.

 

I agree, I guess my point was the struggle to heat is a bit more with -20 windchill which we’ve had here. But 4 - 5 hours I agree.

 

For what it's worth it's been -40 to -50 here all week and I start making heat within 10 minutes of idling from cold start, and it's at temp with light driving within 5 minutes right in the middle. Bone stock nothing blocking the grill or anything.

If I start idling the temperature needle will start dropping after a few minutes stopped with the heat on full for obvious reasons. But if I start moving within a minute it's back to temp.

Something is wrong with yours. I'd guess faulty sensor.

 

Thanks guys, so according to tech stream the truck knows that it's cold because it was showing engine temps between 140 and 150. This morning it was 2 degrees outside so I blocked the radiator and drove up about 30 minutes to tune some trucks (I do OV Tuning), and it stayed at temp. I took that out and drove another half hour out to a store, parked it for an hour (engine off), and drove back home, it got up to temp on its own (from 1/4 way up). Tomorrow I will be going elsewhere and I will see if it will get up to temp without blocking the radiator. If so I believe it was somehow air in the system? I do a bunch of hard offroading so maybe some crazy way air made its way through the system? idk, doesn't seem likely. If the truck was slightly colder than normal I would have never cared, but it was running ~50 degrees cooler. I will keep you all updated.

I also bought that new thermostat housing from Toyota (for over $160), so I'll keep it with me on this trip..being that it takes 15 minutes to swap out... and order a cheaper one (~$40) from rock auto, then I'll try swapping that to see if it changes anything, maybe that thermal unit in my assembly is going bad and heating up too much or something.

Thanks again, everyone. I have built trucks and cars my whole life but I have never lived in the cold lol

 

Just saying, what if the truck's temp sensor is wrong by 50F. (Feeding into engine ECU)...

Next time, after its completely cold soaked overnight outside, befor you start compare coolant temp to outside air on techstream.... if engine says it is significantly colder than air, then something very fishy.

 

Good call on comparing it to outsize temp! I'll definitely do that.

 

Any updates OP?

 

First time I have ever heard someone complain about running cool. Lol. As I see it, are you getting a check engine light? Is the engine running rough? Does it run fine in summer? If no no and yes then why worry.

Also, Colorado is a very dry place and even though temps may be between 0 and 10 it is much colder. Moisture provides an insulating effect. The lack of it creates considerably more heat transfer away from a radiator.

Just saying if you are not getting a check engine light and you are running a low viscosity oil you should be good. Just my opinion. But I am no taco expert by any means

 

Update?
(invested now)

 

All i can say is these engines and cooling system are weird compared to anything else i've owned. I trailered up north last sunday in temps that didn't go above freezing. When running normal highway speeds my temp read normal on the gauge...mid-way. The minute i come to a stop the gauge drops to a 1/3 of the way. Up to speed again its normal, yet i always have plenty of heat. The only other issue is very slow warmup when its this cold. Seems i can travel for a few miles before getting heat. Never owned such a cold blooded toyota.

 

I have exactly the same symptoms. Mine is a 2018 Tacoma TRD off road, auto trans with oil cooler with ~60k miles. This problem happened suddenly from a normal "12 oclock" temp gage reading when warm. I have been searching for a replacement thermostat since this is classic thermostat stuck open symptom, but the thermostat housing assembly always pops up with no replacement thermometer listed. Now I'm wondering if the temperature sensor in the housing is the cause of my problem.

 

I live in Minnesota and often drive when it well below 0F and my 17 TRD off road stays in the middle of the temp guage and I get plenty of heat without any modification.

I have driven in Temps of -20F while on the highway and the heat still worked just fine.

Maybe plug in to to a scan guage and see what Temps the coolant is getting to.

 

how many total miles

running 30 degrees light is not unusual in a high mileage engine

be certain radiator cap is secure

check wiring sensor + dash gauge