1999 Pontiac GA SE Heating Cooling

[tscrater]

I have a 1999 Pontiac GA SE and when i use my heater I get cold air one minute then hot air the next. We have flushed out the system and put new coolant in. The kind that is recommended. The temp gauge will go a little over 200 then down just below 200 at the same time the temp is going up and down. What is the problem? Also my carpet is really wet, all the way to the back seat. It looks like water to us. Please help! Any advice would be appreciated.

Thank you
Tom and Sherry

[prescill]

I had the same problem with mine, going from hot, to cold all the time. for me it was the havc control( the unit that you use to adjust the heat, fan etc) I went to the junk yard and that was it . I never had a problem again. it's easy, pull the trim around the radio and heater control and you will see 2 screws to take out to get the unit out, and 3 wire connectors on the back to take of. Good luck

[daman]

I'm shure your full of coolant???

[tscrater]

Yes, its full of coolant.

Sherry

[daman]

You may want to check into your havc control like Darren
mentioned above..

[2K SE]

I would also look for a heater core leak or at least for a coolant line leak. That water in the carpet is coming from somewhere. Good luck, I hate working under the dash.

[tscrater]

Thanks guys. I will check out all these problems and post what the problem is for everyone once its fixed. Hopefully we get it fixed today. :O

Sherry

[tscrater]

My husband had my car diagnosed at a local garage and they found that the #2 cyl. was misfiring caused by a coolant leak through the intake gasket. In return the cooling sys was getting air into it causing the no heat condition and the heat gauge fluxuating up and down. Also they said if the intake gasket looks ok with no physical damage that you could see, they wouldn't rule out a head gasket being blowed or cracked head. So my husband will be tearing it apart. They told him he should beable to see the gasket physically blowed. They also had pressure checked the cooling sys and determined that the heater core wasn't leaking. They said the water on the floor board could be caused by a plugged drain for the a/c condensor and it is overflowing into the car. Or we have a leak somewhere, maybe a windsheild, vent, or body. I will keep you informed on what we find. Thanks for the help. ;)