i'm having a weird problem with my 98 camaro. when the engine gets hot, i turn on the heat, and it blows hot for a few seconds, then gets cold. not ice cold, but as cold as the air outside. if i turn the fan up higher, it gets cold faster, but if i leave the fan on low, it will last a little longer. does anyone have any idea what would cause this? thanks guys.

 

Have you checked the level in the radiator? Sounds like you got a big bubble.

 

Not enough coolant flowing through the heater core. Check the coolant level. If that is ok, you might have a blockage in a heater line.

 

how would i fix something like that? and what would cause it?

 

Open the radiator cap and see if the level is low. Add more coolant if it is.

 

Low coolant or insufficient coolant flow through the heater core due to blockage.

Prime candidate is sludging from DexCool antifreeze.

Disconnect both heater hoses at the firewall and use a garden hose to *carefully* flush and backflush the heater core. When I say *carefully * I mean don't stuff your garden hose into the heater hose and then *whammo* hit it with full pressure/flow (especially if you have municipal water at high pressure like I do).

I've seen some pretty amazing crap some out of a heater core when flushed.

Could be an air-locked heater core or a hose that's kinked, too.

Good luck.

 

Turns out it was just low coolant. Thanks for the help guys!

 

Low coolant because ________ ?
You will need to keep an eye on the level in the radiator - check when cold - and for external leaks - spots on the driveway/street, or maybe the inside passenger carpet for a heater core leak.

 

+1. Keep an eye on the level. Got to figure out how it got low in the first place. Does your car not have a low coolant level sensor? Mine has one that turns on an idiot light on the dash if the level gets low.

 

+2

If it happened once it will happen again.

The coolant is going *somewhere* and you need to find out where that somewhere is.

And... when coolant isn't filling the system air is in there. That's means oxygen is in there and that means corrosion and possible sludging. All very bad.

The coolant recovery system added to most cars by around 1973 was critical in reducing cooling system problems by keeping air out.