2000 Ford Ranger heater issues

[mayhem69]

Hi, i have a 2000 Ford Ranger 3.0L 2wd. A few months ago it started leaking coolant above the tranny. I was told it was a gasket or seal at the timing belt cover? So they put some stop leak in the radiator and all was well for a few months. Well a few days ago i was going out to lunch letting it warm up (I live in Pa.) I noticed it was blowing almost cold air. So when i got home i also smelled coolant and it was leaking toward the front. It was over a half quart low.

So i took it in and they did a pressure test. They replaced the timing cover gasket, water pump and thermostat. When i left the garage i noticed the heater gauge needle going a little haywire. It would read halfway, then jump down fast towards cold, then back up. It would blow hot, then warm, semi cold air until i ran it about 15 minutes. Then it was so damn hot i had to turn it off.
I just ran it today and the heater gauge needle is doing the same thing. I let it warm up for about 10 minutes. When i jumped in the needle was buried on Cold. I drove 1 minute and it jumped up a little. The needle is going up to halfway , then down to 1/4 cold, blowing semi-cold air, then hot, then cold again. The needle didn't stay at the halfway mark and start blowing hot air all the time for about 20 minutes.
I am about to take it back in the shop. Any of you Ford techs know what is wrong with my baby?

 

[d-kuzmen]

Sounds like it has air in the coolant system, when you get air pockets traped in there thats what happens. I would have them bleed the system and make sure they also had put a new t-stat in it as well.

 

[blacksnapon]

Yeah, Dave's got it. Theres air in there.

 

[mayhem69]

thanks guys!