Ok so long story short my girlfriend has an 03 blazer 2wd 2 door. I drive a 99 mercury Cougar and a 98 Explorer sport. Problem with the blazer that broguht me here is when i turn the heater on it blows cold sometimes and the temp gauge sky rockets. I am baffled by this.. thinking about changin the thermostat but don't know... the main confusion is that it blows ice cold when i have it on heat.. Ideas? Really just started the search for if this is a common problem or an easy fix.. or something more wiht the heater core o somethign.. once friend said somethign about changing the thermostat too and that there may be a bubble in the coolant... don't know, i am a wrench head myself but never had heating problems...

 

Its quite possible that the stat is bad and that the coolant had boiled somewhere in the block air locking it. When you drain the system to replace the stat, pull off the heater core hoses and flush the heater core with a garden hose. Flush into both hoses (backwards and forwards), then reconnect the hoses and refill the system.

Good Luck

 

thanx... don't know how i posted this in the wrong area.. really ment to post in the newbie forum but i guess i screwed up something this afternoon when i did it.... I will try that if she doesn't get it fixed this week while i am gone out of the state.

 

not a problem. And you are in the proper forum for questions on problems. Newb section is for introductions.

 

I moved it from the new member section because you had posted in the wrong spot. I might have forgot to send you a PM that I moved it.

 

tecnically this is a technical question... whether he is new or not..

but yeah

the answer more than likely is the stuck closed t stat... get a new stat that has a fail safe design.. when a fail safe goes bad, they stick open.. so that it wont boil over.. good investment for a car...

and you will know when a fail safe is bad... the car will take forever to get warm.. since the stat is always open.. the water doesnt have a chance to stay in the block long enough to warm up

 

That's why I moved it to this section...

 

Good job m00n!

 

thanx all.. I think when i get home next week i will have to be under the blazer for a lilttle while.. $40 to fix instead of probably 100 or more for a shop to do it for her while im gone...

 

Hey if u get a chance check the level of coolant in the radiator all together (if u haven't already). I had the smallest crack in my radiator that leaked ever so slowly like i'd have to put water in once a month. If this problem has been going on for awhile u might wanna check the water pump too.