I have a 89 with a 22re. Only had it about a month and now it's getting to be colder outside. Not sure what's going on with my heater though. The fan motor works, I have coolant in the radiator. The heat though seems to be working intermediatly. Tonight I was driving and it decided to work. Then I shut it off, turned it back on and the fan blew out cold air. No coolant smell... Just not sure where to begin. Thank you for the help.

 

I would almost guarantee a blockage or air pocket. If you've recently done any work to the engine where you had to replace the coolant, it's likely you have an air pocket.

You'll need to raise the front of the truck as high as you can. I used ramps under the front wheels on my sloped driveway. The cap needs to be the highest part of the engine to get the air out. If this is the problem, you'll need to keep topping up the rad as the air purges.

Just my 2 cents. It's a cheap fix, if it works.

 

With these engines if the coolant level is a little low you will not get heat.

I have found it is much easier to use a tee in the heater hose to bleed the coolant system .

Highest point in the system!!

works for me.

 

Alright that sounds good will def give that a try after work today

 

When the heater quit in my '91 it was because of the block off plate under the dash. Not sure if your '89 is the same, but the plate flaps to block the air from flowing through the heater core. It works on a push-pull cable from the temperature switch in the dash. My cable was broke and would push the plate closed but would not pull it all the way open.

 

Also check the heater valve unfer the hood against the firwall, The cable clip gets rusty and fails and the cable sleeve moves insted of the valve opening and closing.

 

I had a similar problem in an older ford ranger. Turns out the heater core was all pluged up with crap from not ever circulating in the summer months I gather. Anyhow It was intermittent and a blow out didn't fix it either so I dumped in some of that fancy coolant flush stuff directly into one hose of the core (Disconected both the hoses from the fire wall). Let that sit for a few hours and then flushed that out with a water hose. That helped a bit but was still not really working. I then got the idea to reverse the hoses and drive around. After about 20 miles of highway driving I had more heat than ever before. I later noticed that my coolant had quite a bit of gunk floating in it that was never there before. So I guess just running it backwards from from how it has always been was enough to clear it out a bit.

 

All great suggestions. Once you get it cleared up, turn your heat on every few weeks during the hot months to keep that sucker cleared out.