Need advice on how to get heat

Hey all I am new to the group and sure it has been discussed somewhere. I have a 95 Tacoma and cant get heat I have checked the heater control valve and back flushed the heater core. I did just notice when I was messing with it when I would rev the motor the exit hose coming out of the heater core collapses at a little higher rpm anyone have any suggestions to try or might know what my problem might be? Thanks in advance!

 

Blend door functioning?

 

Those symptoms possibly sound like air in the coolant system

 

Air would cause intermittent heat... not no heat.

Wouldn't it? That was the problem in my F150.

 

How old are the hoses? They shouldn't be collapsing.

 

Air can cause no heat, air can cause intermittent heat

 

Hose collapsing? Didn't by chance replace the original with a vacuum hose?

 

Ditto, well over 3/4 of the coolant/heat problems that we get after other people/shops worked on ends up being air left in the system, jack the front of the car up safely or find a steep hill/embankment you can park on and with the heat on bring the engine to around 2000 rpm for a few minutes, helps if someone's watching to tell you when air bubbles stop coming out. We usually use the lift and bring the front up about a foot, this puts the overflow bottle and radiator cap at the highest point so air can exit the system a little easier.

 

I have checked the blend door it seems to be doing its job. I will try and jack the front end up this evening after work and see if I cant get any more air out of the system. Thanks again for all your suggestions I really appreciate it!

 

I would warm her up, not too hot, bleed the pressure off the system and disconnect a heater core line and put a piece of clear tubing in between and start her up again with the pressure cap on the first step. This keeps coolant from coming out and does not allow pressure to build. Then I would watch what happens as I slowly increase the rpms. There should be a pretty steady flow with no air after a minute. The collapsing of the hose is a sign that the core is partially blocked... Think of a paper straw in your mouth, plug one end and suck on the other, the straw collapses.

 

Ok I have checked the flow of the heater core and the hoses are the same temp going in and at the exit after I let it warm up and also burped the system with the front end jacked up. I had the warmest air i have had so far until i took a trip down the road and then it got to blowing cool air again ha ha i have no idea what the problem would be now

 

This gentleman just had the same thing going on. Maybe worth the read.
https://www.tacomaworld.com/threads/no-heat.642058/