No heat in my '98 Bravada?

Question

This summer I replaced the water pump in my Bravada, while I had the pump out, I flushed out the radiator and the pump openings. Once the weather started getting cold I found I had no heat. I took the hoses off the heater core and flushed it out. A lot of rusty looking water came out so I continued to flush it until it ran clear. After this I had heat for about a day and a half and then it went away again. I have tried flusing the heater core again, but cannot get the heat back, any suggestions?

Answer 1

Is the temp gauge in the dash indicating properly? If not, T-stat. If it is, you may have to burp the system because it may have an air pocket in it from the flushing process.

Answer 2

I take it you didn't flush the engine block while you were flushing everything else. What most people don't realize is that there is that there is constant circulation from the engine to the radiator, so if you flush the radiator and remove and debre from it, It will likely just get it back from the block once you ran it again.

So it's important that you flush the whole system, this prevents debre from getting back in heater core, radiator and will help keep from premature water pump failure.

Like a previous poster mentioned, Dex cool is one of the worse ideas by GM for cooling systems, once it starts breaking down, it clumps together and causes blockages.

I'd advise getting flushed professionally.
Good luck and I hope this helps!

Answer 3

It appears you just need a new heater core and possibly a new thermostat. You may have flushed it out but if it corroded onthe inside you could have flushed holes and crap through all internal piping. get a new heater core and replace the thermostat while your at it this should hopefully do the trick. If it's really cold and your thermostat is in the open position it is not allowing the coolant to get hot before it flushes through the system.

Hope this helps if flushing the heater core to begin with helped imagine if you got a new one.

God Bless and Best Wishes.

Answer 4

if the water you flushed out is rusty, you may just need to replace the heater core. the water is more than likely going in and out of the core but not circulating through it.

Answer 5

i dont think u do but look to be shur u dont have a mixing valve on your lines to your heater core this will turn off flow to your heater core when ac is on also be shur that all mode door are working in the heater box this can be hard to becouse most of them u cant see very good and last u may need a new heater core

Answer 6

Take the radiator cap off and run the vehicle. Bleed all the air out of the system. If you keep getting bubbles or the coolant overflows all the time you most likely have a head gasket problem.

Answer 7

That silly dexcool stuff has probably plugged the heater core. You would not be the first.

Answer 8

sounds like your themostat make sure you put antifreeze back in to the proper ratio