Heater

My 96 bravada will not blower hot air out of the heater. This just started. I replaced the thermostat on the engine and still no luck?
Any suggestions.

Does it blow cold air?

Does it blow cold air?

Yes. It blows cold when I turn the knob to the cold but it only blows warm when i turn the knob to hot.
Do you think that the reastat is bad in the switch?

Have your heater core flushed. The dextrol coolant that is used gels up and clogs the flow. A good way to tell if it is clogged is to feel the hose that goes from the top of the water pump to the firewall. It should be as hot as the return line next to it on the firewall. If not, get it flushed. The only other thing it could be is in the climate control, and I am having a hell of a time finding info on my Jimmy regarding the repair/replacement of the system.

Think you!!!
I will try to flush the core tonight!!!

You need to fulsh the core from both directions to be most effective.

flushing the core worked!!!! It now blows hot. Thanks to everyone :biggrin:

is flushing the core a tough job? i have the same problem

It was not too bad to flush. I removed the hoses from the engine not the heater core. That way the hoses get flushed too.
Disconnect the heater hoses at the engine - Then put your garden hose up to the heater hose and flush both ways several times. the water will flow into the heater hose that you have the garden hose up to and it will flow out of the other heater hose. after doing this a while switch sides and flush out the heater core the other way.

well, my problem was a little more advanced than just flushing the heater core. i got to poking around and found my water pump was leaking. so ended up replacing that. just a side note, that cooler fan was extremly hard to get off. but we were intuitive, we used the flat metal bar that locks my craftsman toolbox and screwed it onto one of the screws. so, after a new pump and flushing, we have heat. thanks

ps i cant say that i will be much help on this forum, but i like to tinker

All tinker's posts held in high regard here...we're just trying to keep our Bravada's going.

well, my problem was a little more advanced than just flushing the heater core. i got to poking around and found my water pump was leaking. so ended up replacing that. just a side note, that cooler fan was extremly hard to get off. but we were intuitive, we used the flat metal bar that locks my craftsman toolbox and screwed it onto one of the screws. so, after a new pump and flushing, we have heat. thanks

ps i cant say that i will be much help on this forum, but i like to tinker
I have had the same problem with my heater and have had the system flushes twice in 2 years. This time the heat is sporatic and it now dumps ALL the coolant in one day. I am attempting to find a leak? Does anyone have another possibility other than the core being bad? Any help is appreciated. Thanks

did you check to see if there were any leaks from the water pump? that's where i found my leak. i also had to flush it, but the major problem was the pump.

My used 1998 Bravada has the same type of problem, it blows warm air only when the dial is set to 82 degrees. Someone put Bars Leak in the system! So my heater core is probably plugged also, I will check into that. Thank you for the posts on this. When a heater core is bad, it leaks, when it leaks it leaks coolant into the ducts and then coolant based steam is released onto the windshield, and fills the cab with a sweet smell. For certain, this is when you need to replace your heater core. Until tht happens, flush away, check your thermostat, or water pump (whatever proves to be the problem).

Mine is not leaking coolant into the ducting, so it is probably plugged with the Bars Leak.

Why do people do this? It's like filling you slow leaking tire with "tire slime" when just fixing the leak the right way is the most cost effective.

Anyway, thank you all!

Sincerely,

Reinman

I recommend one of the following procedures for flushing a cooling system. A lot of people are having problems with their cooling systems because the DEXCOOL is past due for a change. This, in conjunction with the defective factory radiator caps, is causing the systems to sludge up and clog. The old DEXCOOL's corrosion inhibitors are weakening, as well, and allowing the systems to corrode.

For system with Sludge:

Buy the following:
2 gallons of distilled water $1
2 gallons of Dexcool $20
Prestone Flush 'N Fill kit $4
Prestone Radiator "Flush" $4

Turn your heater on and leave it on for the entire process

Drain the anitfreeze from the system.

Install the "T" from the Flush 'N Fill kit and follow the directions that came with it.

Disconnect the water hose, close all the drains, add the Prestone Flush, fill with water, get engine up to operating temperature and run for 20 minutes, allow to cool then, drain the system.

Connect your water hose to the Flush 'N Fill "T" and flush one more time. Drain.

Fill the system with a 50/50 mix of DexCool and distilled water. Continue to fill the system over the next few days as the air is worked out of the system.

Throw the stock AC Delco Radiator Cap away and buy a Stant from Advance Auto. ( The AC Delco ones are defective)




For clogged, neglicted, or extremely dirty systems:

Buy the following:

2 gallons of distilled water $1
2 gallons of Dexcool $20
Prestone Flush 'N Fill kit $4
Prestone Radiator "cleaner" not "flush" $6

Turn your heater on and leave it on for the entire process

Drain the anitfreeze from the system.

Install the "T" from the Flush 'N Fill kit and follow the directions that came with it.

Disconnect the water hose, close all the drains, add the Prestone Cleaner, fill with water, run the engine 3-6 hours (you can leave it in for a few days if neccessary), drain the system.

Connect your water hose to the Flush 'N Fill "T" and flush one more time. Drain.

Fill the system with a 50/50 mix of DexCool and distilled water. Continue to fill the system over the next few days as the air is worked out of the system.

Throw the stock AC Delco Radiator Cap away and buy a Stant from Advance Auto. ( The AC Delco ones are defective)