Warrior_84

Right before I left for the 4 hour drive to school I got an oil change (didn't have any time left to do it myself). They topped all the fluids off.. A couple hours into the drive I noticed that the temp guage was fluctuating. It'd go up pretty high and then back to normal. I pulled over and had to add a bunch of coolant. I couldn't really see any dripping from anywhere. Had to pull over again and add quite a bitmore coolant. I still couldn't see it dripping from anywhere. I could smell antifreeze in the cab so I flipped the climate control to cold and turnedthe airoff. It's been about a week and a half now and I should probably add a little bit more but it hasn't dropped near what it did on the way down. I haven't been using my heater at all. Do I need to replace the heater core? Thanks for any help..

Lee

Stock 1991 Ford Mustang GT 5.0

87Stallion

Hard to say. With mine I could tell the heater core was busted because my Windows would fog up and I could smell antifreeze.
If you don't see any leaks it could be the heater core or you blowed a head gasket.

ewgoetz

Have the cooling system presure tested first to make sure where it's leaking from. If your straped for cash now you can bypass it so the coolant doesnt go into the heatercore. Or replace it right away. Bypassing it wont hurt anything, you just wont have any heat.

r.barn

The heater core will either drain out onto carpet below pasngr feet
or out its drain hole on the firewall on pasngr side.

Check to see if either is wet.

GoldNdream

How do you bypass the heater core? I think I'm going to go this route til summer, then I'll replace the heater core!

fourfivefour

Remove the hoses from the heater core and connect them together to bypass it.

Warrior_84

I smelledthe coolant inside my car while I was driving (the heat still worked though)... Can something else cause that?

ewgoetz

Heat will still work. you probably have a pin hole leak in the heater core.

Warrior_84

Alright, thanks again for everyones help... So first thing I should do is pressure test the cooling system to make sure the heater core is what's leaking? Or is it a pretty safe bet? And about the head gasket mentioned earlier... What causes head gaskets to blow? (Is there a simple answer to that?)