Ronsdeal

1999 TA, 91k miles. This summer flushed and changed coolant. After that, runs great, AC works great. Now no heat?

Cocaine_Bird

iTrader: (1)

Your problem must be the Heater core.

Ronsdeal

Hi, and thanks for the reply.
Why are you so sure that's the issue. I know it could be, but only that?
I should have mentioned that when I did the work on my GF car, [original owner], had center dash apart as I was installing new audio system.
Now I wonder if I goofed something up with the hvac controls? Possible?
Also could have sworn that I burped this enough to get out any possible air blocks, but now I am 2nd guessing myself. I will have access to her car on Monday, and then it will go back into storage for the winter. Monday is the day for me to rectify this issue.
Thoughts?

LS6427

iTrader: (2)

Heater cores don't fail....they only leak. As long as coolant is flowing through it.....you have heat.

Here's what I would do....
---Completely cold engine---
Take off both heater hoses from the two water pump ports.....cap off those two heater pump ports so you lose as little coolant as possible from those ports.......Take a garden hose with a spray handle on it so you can regulate how strong the water pressure sprays out. Stick the tip of the spray nozzle into one of those heater hose ends and gently, slowly....spray water into it until you see a solid stream of water coming out of the other heater hose end......then let it run like that for 30 seconds.......under LOW spray pressure, just enough to get it to flow through the heater core and those two heater hoses.

Then attach both hoses.......remove the radiator cap and start the engine. Stand there by the radiator fill neck and wait until you see the t-stat open and coolant start to flow. Might take 10 full minutes or so.....
((If it takes more than 10 minutes go back and forth checking your temp gauge so you don't stand there and overheat the engine....or have someone sit in the car and watch the temp gauge))
As the level drops in the radiator....top it off IMMEDIATELY with water.

Put the radiator cap back on.....see if you have heat.

.

Ronsdeal

Thanks, LS6427.
That will be on Mondays agenda

erickk120

Now you have me curious, I haven't had heat for years now. I will try that trick above see how it goes! I just never felt like flushing it. Specially here in florida where it isn't really needed.

LS6427

iTrader: (2)

Well, after someone flushes their system and then the problem starts, I think of a huge air pocket in the heater core, even though its hard to have that happen because when the water pump starts spinning it should push water through along with pushing air bubbles through.

It could also be that the door inside the dash panel is not switching over and closing off the cool air source......and then the heat never gets directed to the vents.....and cool air keeps blowing out the vents.

So it could be that too....for you and "Ronsdeal"......

.

LS6427

iTrader: (2)

Yup....its a free check that takes 20-30 minutes. If thats not it....you need to see if the door is closing and opening properly inside the dash.....which is vacuum driven. Could be stuck in one position only allowing cool air in.

.

Rocky98

I ran into the no heat issue about 5 years ago and followed the recommendation to pop the coolant hoses off at the coolant pump and flush with water from the garden hose. It fixed my problem for a couple years at which time my coolant pump then died. When I was replacing it, I was sure to flush the heater core again for good measure while I had all the hoses off. My car's been pumping hot hot heat ever since.

Make sure to run water from the garden hose in both directions across the heater core. I would push water in one hose until it came out clean from the other hose and then swapped hoses. Repeated this several times on each hose that runs to the heater core. I find have a pair of EXTRA long reach needle noses helps when trying to pop the hose clamps off at the coolant pump and also for putting them back on.

2ToeRacing

iTrader: (5)

My S-10 would lose heat when it was freezing cold, it worked if it wasn't that cold. I thought it was the blend door like LS6 said. I just lived with it because our winters don't last too long in Atlanta.