Wheels1983

I just bought a 1989 Toyota Pickup DLX 4x4 extended cab with the 3.0 V6 engine in it. The heater will blow air, however, its not warm at all. I took it to Pep Boys and the told me to replace the Heater Control Valve. I just replaced it and air bled the coolant system. The I let it idle for a 15 - 20 minutes, still no heat. Has anyone else had this issue, or other ideas on how to fix the heater? I used the video below to change out the heater control valve.

millball

Did you try and flush the heater core both ways while you had the hoses parted??

The heater core might be clogged.

Also, heat might not be provided if the air doors under the dash do not move to the proper positions when the HVAC controls on the dash are set to their various positions.

Does the heater valve operating lever change position when the lever on the dash is moved from cold to hot?

jaysson_2012

I just got done fighting my no heat problem. Make sure you have the hoses hooked up to the right places. So that one is pressure and one is sucking. Also try flushing your heater core with a garden hose to make sure water can get through it. Check and see if the water is rusty or full of junk, it might mean you have a clogged heater core. If all is well you might have to start pulling the heater core. It might be clogged with dirt on the outside. OR like on mine, the fin that covers it when using a/c might be stuck covering it.

wyoming9

iTrader: (1)

Not only could the inside of the heater core be blocked the outside can also be covered with 20 plus years of dirt.

Rodent nests are something to think about as well

blend door needs to be open allowing outside air to flow through the core

The cable does move your new valve??

You did make sure it worked before installing ??

McMagical Eng.

Flush that core. I hooked a garden hose up to mine a few years back and a massive plug of mud shot out. I ran the hose for a while till the water stopped coming out brown. Heated right up after that.
Someone else probably has a much better writeup...
Hook up the hose with metal hose clamps, pull the bottom hose attachment so it drains downward under the truck, (never hurts to park on a slope leading AWAY from your garage). GENTLY turn the water on to build a little pressure, until it starts to flow. If you have a bad clog, it might take a little pressure to blow it out. Take a look while you do this to see if there are leaks or bad hoses. Add your favorite core fluid and seal it up. Its not too hard and doing it yourself can save some cash.
Stay warm!

Wheels1983

I replaced the heater control valve, then followed pretty to close to this Youtube video on how to flush the heater core. Using the clear plastic tubing really helped out a lot. I air bled the system again, and then let it idle and warm up for about 15 minutes and took it for a ride around the block and it the heater works great now.

Solomonp

Hi. I am having a similar issue. '89 22r pickup
blowing only cold air, no heat:/
-changed the thermostat
-flushed the heater core
-looked at the heater control valve and its working (as far as I can tell without pulling it off and looking inside)
should I get a new heater core? Get a new heater control valve anyways? Any other ideas? Any fuses or wiring it could be?
thanks!

thefishguy77

iTrader: (1)

Hey welcome. This is a 3 year old thread. You might have better luck starting a new thread in the newbie section. Lots of activity there and lots of helpful people.

Co_94_PU

iTrader: (-1)

did you ever get clean unobstructed flow from the heat exchanger?

Verify the valve opens with the cable and isn't plugged, probably should have thought if that when you had it apart to flush the system but that's maybe just me. Are you getting atleast some hot water through the valve, simple touch test will tell you.

The vent selector is mechanical 80's no fuse, motor or electric parts involved. I vaguely remember there not being a blend door between AC and heat. This means if it blows your problem isn't electrical.

Look in between the slots of the cowl near the windshield wipers, if you don't see screen material you may have a build up if debris on top of the heater and will need to clean out the air box..

Solomonp

Thanks for the reply. I replaced the heater control valve. Cleaned out the leaves around the heater core. Checked to see if the system was holding pressure. Still no heat. More over my coolant is disappearing with now visible leakage. Inside the oil cap there was a bit of coagulation of whitish yellowish goo... I think that there might be a leak. Plus there are new head bolts. I'm wondering if they tried to replace the head gasket. But there was some warpage and it didn't fix the issue so they sold it.