Hey,I have a 97 s10 blazer. 4.3 liter v-6, n 4 wheel drive.I have only one problem with my truck, theres no heat! There is a brand new alternator, radiator, thermostat, radiator capand water pump in it.I completely flushed the system to try and see if debri was clogging the lines and nothing. It does seem that the system is airbound tho. Is there any way to bleed the system?, or is it something else? Recently i discovered a leak of coolant inside the cab, could this have something to do with it? Its way to cold out to not have heat so ANY help is appreciated.

 

If the coolant was on the pass side floor then your heater core is leaking coolant and won't allow it to heat to the levels you are hoping for.....to replace it will require removing the dash.

I was out in a junk yard today looking for a part for my blazer and saw the heater core in its installed location with the dash off and it is not an easy job....you will have to remove the bolts holding the upper dash to the body and that is not easy.....so good luck....

 

If you do a search, I believe that lastcoupe wrote an excellent post on heater core replacement.