Overheating Tacoma

I have a 2013 Tacoma TRD offroad. Last summer it over heated twice but then stopped and never did it again. It is now overheating more frequently. It only does it when I’m going slow and up hill. Or when I leave it running with the AC running on. However, if I put the heater on it stops the temperature from rising or cools it down.

I’d imagine it’s one of the following:
Water pump, Fan Clutch, Thermostat or Needs a coolant flush. But I could be way wrong I’m not all that mechanically inclined.

Trying to narrow it down before buying all 3 and replacing them.

 

Mileage? Miles / years elapsed since last coolant flush?

Fan clutch diagnosis isn't hard:
https://www.youtube.com/watch?v=N3DitIVc1n8
https://www.youtube.com/watch?v=vgWJN4EEl-U

Water pump have any leaks? Does it sound like gravel or marbles in it? If not, it's probably OK.

 

when was the last time you cleaned your radiator of bug remains and dirt? and what's your coolant look like, no harm in running just water for a few days to start with a flush and decide if you need to do more

 

Start with the basics, have you checked the coolant level and condition in the radiator (not just the overflow bottle) with the engine cold?

Is the radiator, A/C condenser, and area between them clean and free from debris?

Next thing is the fan clutch, with the engine idling hot the fan should be spinning at a moderate speed and moving a moderate amount of air. If the fan is turning slowly with the engine running and/or keeps turning more than about a second after the engine is turned off it's bad.

Very rare for a water pump to fail in a manner that would cause it to stop pumping or lose pumping efficiency, typically they either leak or the bearings fail.

Thermostat is possible but if it gets stuck closed you would overheat under all conditions.

 

I'd drain the radiator and block, fill with water, run till hot, then drain both again and refill with fresh coolant.....if it's over heated once before the coolant likely could stand to be replaced at the least anyway.

Also with the overheating happening when it's sitting still that would really make me want to check that fan clutch.

 

Light a cigarette and hold it near the grill, see if the smoke is getting sucked through the radiator fairly quickly

 

Or a left over smoke bomb from the fourth of July...


Oh, and something often forgotten but worth checking is the belt and tensioner.

 

I have never dealt with this on a 2G so I can't say specifics, but I can say vague things

when you get up there in years and miles, if you want to be safe and do preventative maintenance, you can replace the WP.
but mine still works on an 08 with likely higher miles. I still need to replace it, it's just a pain.
I assume yours being 13 it's not having HG failures like 05/06.

temp sensors can fail, but that's more of a German car thing.

fan clutch? Test it by seeing if it has resistance when you push it. Make sure it spins when running too.
Tstat? I don't think that's testable. But why not throw one in. They're easy to change, don't really spill coolant during replacement, and are cheap. You could start with that.

Coolant flush? I mean yeah, they're good to do, but doesn't usually cause overheating. So I'd say if separately it's due, then go ahead and do it.
Hopefully you're not low on coolant or leaking it.
Replacing the coolant is good maintenance. And filling it properly will give you the peace of mind of ruling that out of the equation, knowing the system is full and without air pockets.

any one failure can cause issue. But so can the tstat, being kinda the easiest and cheapest to replace. It's plastic.

IDK about when hot/engine on, but when cold, you can potentially also spray clean (gently) the condenser off (idk about reaching the radiator) to get insulating dirt off. But that's a minor thing, not a cause of major issue

I try not to be greedy with the Tacoma and think that just because it works, it should be neglected
because if you think about it, look at most other vehicles out there, that work in a similar manner
yours is 2013. it's not 2023. That's 10 years.
Most other cars are needing to get all of those parts and more by that time.

 

Long ago, I was shown a film on testing a thermostat in high school auto shop. They suspended it in a pot of water with a thermometer in the water. Turned on the heat, when the thermometer reached whatever temperature, the thermostat opened. Kinda impractical, you’d have to remove it.

I use a ir thermometer, engine running. I’ll point it at the block, thermostat housing, and upper radiator hose. When the thermostat housing reaches temperature, the upper radiator hose temperature will go up, then slowly go back down. I also like to read the upper and lower radiator hoses to see how well the radiator is working.

I use a Raytec mt6. In 2011, all my tools were stolen. The old one worked much better than the new one. It does work but it’s difficult. I wouldn’t recommend getting that one.

 

Basics:
Change the coolant draining and flushing block via 2 block drains one each side and petcock on radiator.
Cheap also is a new thermostat that comes with the housing when the coolant is already out.
Buy a new pressure cap note the rating is stamped on it.

Go to McGeorge Toyota site online enter your VIN and lowest OEM prices and very fast usually within 3 days.
Aftermarket coolant can be bought at parts stores in pink specifically Asian with Toyota listed - need 2 gallons of the 50/50 premix but OEM same price.

TW has help videos of coolant changes if you need one.
The thermo housing is kinda a bitch to get to the little nuts holding it on and it really helps to own a set of the hose clamp pliers as channel locks don't fit in there.

 

Any word on your truck? I hope you have been able to find an issue or come to some sort of conclusion.