Help no heat 6 cylinder 2011 Tacoma

Went the other day to firestone for the no heat problem, they change thermostat, upper and lower hoses, flushed radiator and changed coolant, and new radiator cap. Still no heat. They said may recommend a head gasket. Freezing my ass off in Colorado. Any advice will be greatly appreciated.

 

If it was a head gasket other symptoms would be smell of antifreeze, oil contaminated with antifreeze or smoke blowing out the tailpipe.

 

Truck runs great. Any idea then what it could be, or where to look?

 

Are both the heater core hoses hot to the touch? If 1 is hot and 1 is cold you could have a restricted heater core. If they are both hot then make sure the blend door isnt stuck in the cold position

 

Take your truck somewhere else, it definitely isn’t a head gasket. First I’d be looking at the heater hoses and heater core. I assume it blowing air out the vents?

 

Yes, but cold.

 

Lesson 1) find a good independant mechanic. Not something franchises are especially noted for. It happens, but rarely.

Lesson 2) listen to @b_r_o

 

Sprig, I will be taking it elsewhere. I will check the hoses. Thank you. I appreciate all the info.

 

It could be the actuator for the temperature door. it's a somewhat common problem on Delphi HVAC systems in GM vehicles, but I'm not sure if it's a big issue on Tacoma Delphi systems. That shop you went to was just throwing parts at it. I would avoid that shop in the future.

 

Does the dash engine temp gauge function correctly (engine temp getting hot or staying cold)

 

The thinking behind a headgasket failure is that it causes excessive pressure in the entire cooling system. This pressure can sometimes inhibit the flow of coolant through the core.

Headgasket could be a problem but not yet, need to check other simpler stuff first. The Firestoners should at least have some more evidence to back up their HG suspicions, like a block test.

Before the firestone work, did you have a slow loss of coolant that wasn't dripping on the ground? Like, did you have to top off the coolant level on a regular basis? That would /could be a sign of a HG leak..

 

I concur with bro, that is exactly where I’d be looking

 

Simple thing to test.... turn on the ignition switch, do NOT start the engine. Turn the temperature knob from full hot to full cold. You should be able to hear a very faint "whirring" sound. Similarly when you turn it back from cold to hot. If not, then you have found your problem.

 

Possible to manually open heater control valve near firewall?

 

There is no heater control "valve" in a second generation Tacoma. Full water flow through the heater all the time. They use a servo motor to blend hot and cold air.