Problems with heat

So I'm new to Tacoma world but I need help. My 05 Tacoma has no heat at idol but when I rev the motor above 2000 rpm's or start driving the heat works. Half the radiator on driver side is cold including lower hose. Hoses to heater core a hot and so is upper radiator hose. Truck never over heats, temp gauge sits halfway up like normal. I've replaced thermostat twice new radiator and new water pump. Still no progress. If anyone has gone through this or if you have ideas I'd appreciate as much help as I can get.

 

I'm not sure but I think it may be the fan clutch but I'll let someone that really knows chime in

 

Could it be the heater core? I wonder how hard it is to get to to change it out. Some cars make it dang near impossible.

 

Not sure if it is. Hope it's not cause my brother is a mechanic and he said that would be 8 hours taking dash apart to get to heater core. We tried flushing cooling system and took a garden hose to the heater core. Had good water flow and didn't see any chunks coming out.

 

Didnt you say the top hose is hot and the bottom is cold? I use to know what that meant for sure, cant remeber at the moment, but it certainly means that the coolant isnt flowing through the system.

 

You got a big old air bubble in the system.

 

^^^This. And don't even think of going after the heater core. Its an unbelievable job to get to it.

 

put it on ramps, open radiator cap, let it burp, fill radiator back up. the uphill slant will do the trick for ya i suspect....

 

Good advice in post #8. Worst case - you may need to flush the heater core. If that's needed, I'd clean out the whole system - new coolant. Winter's coming so you might want to do that before it gets ugly outside. Youtube is full of heater core flush videos.

Here's some repair doc for your '05:

http://www.customtacos.com/tech.old/files/05FSM/repair.html

 

Ok thx guys I'll give that a try. Oh and when I replaced thermostat I didn't get oem so there's no jiggle valve. Anyone know if that's important to have that valve on thermostat?

 

jiggle valve....

http://www.stant.com/index.php/english/products/consumer-products/thermostats/faqs/

2 comments on jiggle valve - 2nd one addresses your situation...maybe.

 

My first thought is what Jimmy said.... I'd burp the system first.

 

So I put an oem thermostat and burped the cooling system and finally got the thermostat to open last night. But today having the same problem with no heat. Just drove my truck a few miles at 3000-3500 rpms to help heat it up and sat in parking lot for last 40 minutes running at 2000 rpms finally opened thermostat again. Anyone know why it takes so long to open up, is there a break in period or is this normal to take so long?

 

Is it possible to install the thermostat backwards so that it's open all the time causing it to take forever for the engine to heat up to operating temperature? Since you used an OEM thermostat I'm assuming the temperature it opens is correct, but maybe doesn't hurt to verify this.

 

Fast fwd to about 1m10s in video - 1st Gen Tacoma - does not matter - concept the same. One side of tstat longer than the other. If you had the sides reversed, the tstat housing would most likely not go on. Make sure jiggler valve is at 12 o'clock or very close to it. Bleed the system again, this time elevate front of truck way up with floor jack and run engine with radiator cap off. Blip the throttle a few times once coolant gets warmer.

https://www.youtube.com/watch?v=aZEYAkdyymg