Heater output and engine temp

Coming from a 3.4 that cooked me out of the cab, my 2013 with the 4.0 just doesn't get that hot. I've noticed in the winter temps that my heater just isn't getting that warm. It seems to take a long time for the cab to get comfortable. Today it's 18f which in the coming months will be balmy compared to the -30s.

Scan gauge shows 180-182 for coolant temp. The factory gauge shows the needle right in the middle. Coolant is a factory Toyota spec and has not been changed since my ownership of 2 years. It appears clean and topped off. The cabin filter is new. I've felt the heater hoses on the firewall and they are very hot.

Could the thermostat be bad?

 

180 is the correct operating temp so most likely not the thermostat.
Make sure the radiator (not the overflow bottle) is full, if it is you may try flushing the heater core with a garden hose.

 

as said above, flush the heater core. my '13 doesn't slack in the heat dept.

 

Do you have restricted air flow, or good air flow with just air that's cooler than you need?

 

air flow is adequate although on HIGH my blower does seem a bit loud. But overall, it's the seemingly tepid temperature I'm not happy with.

 

both hoses should not be hot

You have a blockage or something not allowing air through the heater core

 

I've found the heater to be a bit weak since new. It just barely has enough heat to be comfortable at -40C.

 

at -40, do you block off the rad some to increase heat?

 

-40c and -40f are the exact same temp. It is the one temp where they merge. Plus, at -40 anything, don't go out unless you are at gunpoint (the gun might not work anyway at that temp, but why take the chance)

 

I have not tried blocking the rad. The engine does come up to its normal temp, but the heater just isn't making it at that outside temp.

 

block rad 50% once it gets to under 0, there are some button types that can be adjusted as needed

under the hood, there is a cabin air intake on passenger side, you can block off a portion of it to reduce cold air flow in if not using recirc mode

another option is to run a second heater core into the cabin air intake to pre warm that icy air before the real heater core heats it

 

40 below in sw bc is impressive. Shit that’s colder than Fairbanks on average. Fuck that’s colder than the solidifying temperature for coolant.

 

I believe the Tacoma heater core does not have a flow regulator. Instead the heater core gets full flow and they us a blend door to mix in outside air to regulate output air temp. If the blend door actuator is not working or door is sticking,low heat output could result. Door lets in lots of cool air for low settings and fully closed on hot setting. Sounds like yours is not fully closing. This all assumes that coolant is not low.

 

Just spitballing here, does it get warmer while driving? I haven’t been through -40°, but we’ve had a few -20°F snaps and the heater doesn’t do nearly as much while idling. Even after driving, if I park up for a couple minutes, it cools down to lukewarm until I get on the gas again. Does barely anything if I’ve just started the truck up in the morning and let it idle for a while. Needs rpm’s to get any significant heat into the cabin. Once I’m on the road it gets toasty enough to keep me comfortable. Always assumed that was just the nature of the beast.

as mentioned above, could be a blend door issue. Maybe flush your heater core out and see if that helps.

 

Nothing on a vehicle is going to work like it's supposed to at -40 degs.

I'd try backflushing the core with a hose and see if scale comes out.

 

We kind of got off the rails here with the -40 stuff. I certainly do experience that here in Minnesota and I wouldn't expect any heater to keep up with that. Going back to my original questions, I did check the temp at the firewall and found a 25 degree differential between the hoses. That makes me think that the heater core is working correctly.

To answer other questions. The coolant is topped off in the rad and overflow. Once I get rolling and some miles under it, it heats pretty decent. Forty minutes in the truck the other day in 20 degree weather was pretty comfortable. Maybe it's just taking a long time to heat all the plastic in the interior space? I will try and figure out how to check the blend door actuation. Thanks for the tips so far.

 

I've never seen -40 in SW BC, -20c is about the coldest I've seen here. I ran into -40 temps near a place called Takla Landing at a logging camp.

70/30 antifreeze is good to -65c. You prepare, especially if you're going into the bush in winter.

 

Skeena neighborhood.
+1 on 70/30 at those temps.

 

Sitting on the seat at those temps is like sitting on a brick, the foam doesn't give at all.