Couple months ago my heat would work normal, have no ac but heat was hot, than my rad was leaking due to it being the orginal rad, but while it was leaking at idle it would only blow hot air while driving, replaced the rad and now it only blows warm air at all time, than all of a sudden my gas went to ****, probably getting less than 20mpg...so I was reading and narrowed it down to a bad thermostat... Changed it today ran it and it actually got hot air while taking it around my job...turned it off to top off the coolant than on and it went warm again..not sure how gas is yet but any ideas, please help to cold for no hot air

 

Also changed the radiator fan sensor in the thermostat housing, just wanted to add that

 

Did you bleed the system?

 

Ditto the above^^^, it sounds like you have air in the system, "it actually got hot air while taking it around my job...turned it off to top off the coolant than on and it went warm again". 94

 

Yeah I bled the system again feels like it's back but I'll see when driving home, also would this effect the gas mileage ??

 

Yes it can as engine will not be at proper temp. 94