My truck has zero heat comeing from the core and Tryed bypassing the heater valve and there is still nothing and I wanted to know what I should do next, Do I just flush the core? and if so how? Any help would be very appreciated!

 

Flush the heater core first, there're 2 hoses in the firewall, the inlet line (the one with the control valve) and outlet line, use a garden hose, back flush's recommended.

 

Alright I just did that and then I went on a errand to get the engine temp up and I still got no heat from the heater I have no idea what Could be the problem
also if it helps its a 22RE

 

I seem to recall and this is a vague memory from 20 years ago, swapping the engine in my 84 4runner and finding one of the hardlines of the cooling system fully restricted. This was on a 20R.
That, or make sure you have a thermostat in place or check engine temp with a laser thermometer at the thermostat housing to see what it reads once the engine is up to temp.

 

Putting precisely what vehicle you are working on in the signature line helps people figure out where to start on a problem.

Search the forums here for a post by Terrys87 (IIRC) he did a very through write up on the heater system with pics.
You may want to see if there are any blockages in the ducts or something keeping the vent doors from opening.

 

Mine was badly clogged with very little heat output. I tired multiple times to find a new replacement but with no success for issues of fitment or extension tube attachment. I paid a local radiator shop to "rod" out heater core then later to solder extension tubes to core.

I also tried multiple flush techniques and once even blow a head gasket after debris from heater core clogged a passage in the HG. Best advice do it right the first time and forget about it. Simply not worth the time of half measures. I do not no of a magic solution that is an easy fix for a severely/completely clogged heater core despite the many good intended opinions post and solutions.

Had tried:
flushing
Flushing just heater core by tubes routed just to heater core
flushing heater core only with CRL
Flushing heater core with phosphoric acid, DO NOT use phosphoric acid in coolant system or on aluminum aftermarket heater core.

Had varying amounts of success improvement but I now live in an area that the heater core needs to be at peak performance. Some improvement was fine when I lived in warmer climates but not now. So you might wanna factor that in.

 

Thanks guys I Finally got it working yesterday, the problem with it was the hose going from the block to the heater valve is plugged .

 

If your truck's a 4Runner, did you flush the rear heater?

Good!

 

I have a DLX so no rear heater.