I need help with heat

Dont know where to start to look.
Heater blows cold , thermostat replaced ,new, working. Radiator does get hot. Still no heat.
On the other side
Ac works but stays same temp through the blue, white,red, range.
I didn't post this because it did not make sense to me.
So I went back out. I found my overflow reservoir does not hold liquid. Now things make a little bit of sense.
Thoughts ? Am I going in the right direction?
I'm thinking I have a pressure problem. If I plug the overflow I have a temporary fix.

 

Not sure how the over flow tank would have anything to do with it.
The heater core is on the other side of the system form the overflow tank.

Is the radiator full of coolant?

 

Blend door actuator?

 

Gonna need a year to help you more.

1995-2000 was cable actuated, 2001-2004 is electronically actuated.

 

Sorry 1998 , everthing seems to be moving correctly from looking under the dash.

 

Rad is full

 

Have a buddy move the temperature knob in the truck. Watch the actuator at the heater hoses in the engine bay to see if it's moving the valve.

 

Bad Radiator cap will also cause the no heat issue.

Just where is the coolant going is the overflow tank cracked allowing it to leak ?

The coolant needs to be able to expand if you plug the over flow it will push out the next weak link .

 

The ground ,it goes to the ground straight through

 

Check the heater valve that's right in the middle of your engine bay by the firewall. I have a 98. OEM went out a few years back and I've replaced it with about 3 rockauto ones. I might break down and get the OEM one. lol Not saying that's your problem but that was mine.

https://www.toyotapartsdeal.com/oem/toyota~valve~assy~heater~water~87240-04020.html

 

Well I went ahead and I swapped out the thermostat. Checked the valve at the firewall.
All looks good. Drove from Denver to Dillon and back, around a hundred and sixty miles up and down passes I won't tell my top speed, but fast. No overheating issues, but still no heat just ambient temperature coming through.
I pinched all hoses ,all of them were hot but there's no flow . The fact that I'm not overheating kind of boggles my mind but I'm going after the water pump. I'll do the timing belt while I'm there. Anybody recommend what brand of kit is best?

 

Clogged heater core also. If no coolant flow id guess water pump but not over heating so id lean towards the pump working

 

I wonder the cable still moves on the valve in the heater hose but the valve is broke so it does not move.

If the water pump has failed I never saw one that the bearings did not fail and start to gush coolant out the weep hole

If the shaft snapped the impeller stops so things get warm rather warm.

you did have the air set to fresh the heat is rather cool if left on recirculate .

Even with the AC on it will get hot ask me how I know.

 

Took hose off one side poked a glow rod through. Moved valve with cable ( cold) , no go with the rod.
Agree with you on weep
No over heating

 

I will revisit the hoses . One should be wet, one dry if heater core is clogged

 

See if you can get water to flow through the heater core with a hose hooked up to either side and at least you’ll verify the heater core isn’t clogged.

 

Sorry Its been a while.
I replaced my timing belt and gear along with the water pump ( old was working) thermostat ( twice in two weeks) and still no heat. Truck has 330,000 miles. With engine running, I have observed flow before the valve on the firewall. I have observed flow at the output of the heater core. I have observed flow coming out of the engine at the top outlet before the rad.
My conclusion is everything is working fine. I am missing one physical property, friction.
Compression 120 119 116 117 119 117

 

Do you have regular operating temperature?

 

My my gauge reads normal to just under, of course that's my observation of the gauge.
The bottom rad hose is cold, the rest hot.
My theory: engine gets hot (180) thermo opens , cold water closes it fast and completely. Engine never heats water up enough to need a radiator