Heater Core Question - UPDATE

[chr1s]

How do you know when it goes bad?
My problem is this: Sometimes my Wag blows heat after 5 minutes, sometimes it takes 20 minutes. It will blow cold, then all of a sudden hot.
Today I bought new coolant, a new radiator cap, and a new thermostat.
Since I bought the Wag in June and havent drained the coolant, I figured now would be a good time to go through everything before it gets really cold.
My heater core isnt leaking so dont think that its the culprit. Could I be wrong?

[ October 08, 2003, 06:10 PM: Message edited by: chr1s ]

[Bob Barry]

If it never heats up, or you get mist on the inside of your windshield, or you smell antifreeze when you turn on the heater, then it may be shot.

But if it's just intermittent, then it's probably air-bubbles in the system.

[J4GRAND]

Low coolant level or a bad thermostat will cause the symptoms you describe. Is it still doing the hot/cold thing since you replaced everything? If so; I'd have to say air in the system.

[chr1s]

Sorry, I meant to say Im putting all the new stuff in tomorrow.
I dont get any of the misting or coolant smell inside of the cab. I figured the heater core usually lets you know when its going bad.

[Oracle]

Sounds like air to me also. Check the heater hoses for cracks or leaks under the hood and look for drips under the housing. If dry sounds like you just need to make sure those lines are bled when you refill the system.

[chr1s]

Seems like it was the old thermostat.
Flushed and filled it with new coolant, threw on the new thermostat (195 degree) and cap.
The jeep now stays at a steady temp just under the 200 degree mark on the temp gauge and blows HOT air. I am a happy camper smile.gif