My 92' Ranger With California Emmisions installed has an intermittent heater. I can be driving down the road and the heater works fine, then it will blow cold air for a while, then back to heat.

Any suggegestions would be appreciated.

 

you have an air pocket in the cooling system. what engine do you have? i had that problem in my 86 shop had it for a week and then i found the problem by my self. my thermastat housing was leaking at the gasket when cold and then was pullin in air.

 

I have a 3.0L V6.

How do u get rid of this air pocket?

 

you need to find the cause of the problem. does that truck still have the cap on the radiator?? if so you just sit there let it run and add anti-freeze. and fill the bottle. i could most of the time run the air pocket out of my 2.9 do you have a temp gauge does it run up to hot while you heat is gone?

 

My radiator cap is on. My Temp gauge has been intermittent,( dead cold indication sometimes) since I had my heater hoses replaced 6 mo. ago. Recently I wiggled the wire comming from my thermostat and it now seems to be indicating OK. (a little above center and within normal range)


BTW, I just went and looked at my radiator overfill and it is empty. I guess this could be the source of the air pocket u were talking about. I will fill it and check it out tommorrow.

 

yeah keep that full and look around your engine for signs of a leak. how cold does it get where you are. do you run the green anti-freeze?? if there is a leak sometimes you will be able to see some crystaliztaion where the chemicals stayed and the water evaporated. start it in the morning and look around. that is how i figured out my ranger sitting it the lot of the shop talking to the tech and we started it with the hood up and i was looking and saw the trickle running out onto the manifold. let me tell you i was not happy about spending the 180 dollars to find the cause by myself..........

 

I topped the radiator with water. Will have to get some antifreeze tommorrow. I will look for leaks tommorrow also. Ran the truck afterwards and heater seems to be working. ( Do I feel stupid of what? lol) Thank you for taking the time to help me out

 

not a problem. how do you think i felt that -15 degree day out in the shops parking lot....... and then having to go in and pay too.

 

Wildduffy , The blend door that controls the flow of hot air from the heater core I believe is vacuum operated . Does the cold air problem come on when the engine is under a load , low vacuum condition & return to warm air when the truck is not under a load , high vacuum condition ?