My heat blows ICE COLD.... help

[1998camaro]

Last night the heat was fine. Blew nice and hot. Tonight when I went to get in car the heat blows ICE COLD. I 'think' I hear a slight "roaring" sound coming from underneath the hood that wasn't there before. Does anyone have any idea what is going on here?

I am praying this isn't the heater core because I read that is a ****** to change.

I also read that I can check some kind of lines and check if they are hot.... Where are those located ?

Random facts:
The temp still goes up to 210 on the gauge.
Just replaced thermostat about a month ago.

[99v6bird]

Re: My heat blows ICE COLD.... help

Have you checked the coolant level in the radiator?

[pace2006]

Re: My heat blows ICE COLD.... help

Check to see if your passenger floorboard is wet every once in a while. Also watch out for steam coming through the air vents. Either of those will be a tell-tale sign of a heater core gone bad.

[1998camaro]

Re: My heat blows ICE COLD.... help

Passenger floorboard is never wet that I am aware of. There has never been any steam coming from the vents. I have not checked the coolant in awhile, but could that cause it to become ice cold in one day? I guess I will check that in the morning or anything else that you ladies and gents thing it could possibly be.


UPDATE: Had to go to the store and I had to drive the camaro as it is my only form of transportation. Heat worked great, just like usual. I dont want to be in the same situation again where the heat goes out. I know this is a problem I need to fix I just dont know what it could be. I am going to check the coolant level tomorrow. Any thing else I need to check ???

[99v6bird]

Re: My heat blows ICE COLD.... help

I haven't had that problem in my fbody, but I've got a dodge that doesn't blow heat when the coolant is low.

after re-reading your post, you mentioned a "roaring" noise from under the hood while blowing cold air...I'm wondering if the a/c was on and the "roaring" was the engaged compressor?

this thread discussed similar "no heat" problem in a 94, but no resolution
http://forum.camarov6.com/showthread...highlight=heat
fwiw, the gmpartdirect.com that was referred to has a blow-up of the components in a 98 heater box.

also, has the cooling system ever been flushed and the coolant replaced?

re "I also read that I can check some kind of lines and check if they are hot.... Where are those located?" :
They are referring to the 2 rubber hoses/aluminun lines that supply warm coolant from the water pump on the front of the engine back to the heater core...the hoses connect to the firewall on the right side of the a/c box on the passenger side of the firewall. I think the idea was to see if they were hot and circulating coolant into the heater core.

Please post up when you figure it out!

[Rob Bell]

Re: My heat blows ICE COLD.... help

This is what I would do:

1. Check coolant level

2. Check those heater lines mentioned above when the engine is fully warmed up. Both lines should be hot. If one is hot and the other cold, the heater core is plugged. It probably would need replacing.

3. Check the temp blend control on the dash to make sure it is moving the blending mechanisms properly.

Maybe there is some air in the system that is getting trapped in the heater core.

As an aside, ever since my car was brand new, when I take a left turn, cold air blows from the vent next near the drivers side window. F-bodies are some straaaange cars.

[nascar24jd]

Re: My heat blows ICE COLD.... help

I am thinking blend door...

[Rob Bell]

Re: My heat blows ICE COLD.... help

Me too. I'm assuming it's cable operated, so it seems odd that it would work, then not work, then work again. You'd think it would either work or it wouldn't.

[Tom Rs]

Re: My heat blows ICE COLD.... help

i have the opposite on my 94 i think... blows warm but not cold. how can i check out the blend door ?

[shiznizzal24]

Re: My heat blows ICE COLD.... help

could it be a hose is clogged?

[Bird_Of_Prey]

Re: My heat blows ICE COLD.... help

Me too. I'm assuming it's cable operated, so it seems odd that it would work, then not work, then work again. You'd think it would either work or it wouldn't.

It's vacuum operated.