I am having a heating issue with a 84 22r 4x4. The problem is it is heating the cab but very little and sometimes it will fluctuate back and fourth from medium heat to very little heat. It never gets super hot like these 22r trucks are suppose to. I have literally done everything except replacing the heater core. I have replaced the thermostat, took the heating control valve off and cleaned and greased it, undid both in and out lines on the heater core hooked up a hose and flush it all out. I am stumped.
I have read through previous threads/posts on this subject and none of them I found had the heat fluctuation issue I am having.
I am at this point in need of a little help.

 

anyone??

 

I'm just throwing this out there, bc I am not an expert by any means. But, could it be the water pump? If it is going out, would it cause a fluctuation in pressure that would keep water from flowing through the core correctly?

 

Thanks for the input. I figure I would try to figure out if it was anything other than the water pump. I really don't feel like tearing apart the front of the truck if I don't have to.

 

Did particulate come out of the heater core ? If yes perhaps replace , I hace seen this twice before , the fan of the heater unit was missing fins in one case after replacing everything was better , the other tim it was a halfway connected heater duct the duct that goes to the vents , this was on other vehicles than toyota but may be of interest to you GOOD LUCK

 

Did you have the heat control set to hot when you filled the coolant?

Are you low on coolant?

Is your engine heating up all the way? Where does your temp gauge sit when warm?

I would open the cap, set the heat to hot and warm the engine all the way up occasionally squeezing the upper hose to "burp" the air out, if any.

 

did all that!
Some green sludge came out of the heater core the first time I flushed it. It wasn't much but it was something.

The temp gauge after heating up sits 1/4" below half way. I really don't know what else to do here. Could be there is still air in there. Do I squeeze the two hoses at the firewall? The ones that go in and out of the heater core??
thanks everyone!

 

It could be that your heater core is plugged up.

Squeeze the upper radiator hose bout half way down it.

Did you check the heater valve for movement? Make sure the cable moves freely and fully opening the valve. Valve might have green sludge in it?

 

I assume the radiator hose at the front of the motor??
I did flush the heater core with a high pressure hose. It started out green then clear and was free flowing thereafter.

 

Yep, one that runs from radiator to the thermostat housing.

If sludge came out of the heater core, I wouldn't be surprised to find more than a couple of the passages blocked off.

 

OK MAN!!!
Thanks for your help. I have tomorrow to figure it out and that helps quiet a bit.

 

Good luck, I hate it when my heater doesn't work.

 

If you have to replace the heater core, its not as hard as it looks. You do need to remove the complete dash to get to the heater core, and its just a matter of finding all of the screws and a couple of hidden nuts and bolts, other than that its easy to do. Ive replaced heater cores in tow 86 4Runners and its more time consuming than anything else, the first one took me six hours and the second one took me four hours because of the experience of doing the first one.

 

FIXED!!
More heat in that old truck than you can shake a stick at!

I had to burp the system. Jacked up the front end, turned the heater on high, started the truck, opened the rad cap, set a brick on the gas pedal with RPM at round 2500 and squeezed the upper rad hose.
Bubbles galore. After about 15min of squeezing the motor was warm and I put the cap back on. I got in the truck and there was heat pouring out of the blower.
Thanks everyone for your help!

 

Awesome, love easy fixes.