Odd Heater Problem


New Member
Feb 17, 2007
Hey guys whats goin on. I have a slight heater problem and its cold as hell outside and i'd like to figure out what the hell is going on. When engine reaches operating temp. I turn the heater on. It gives of heat for like 10sec then cools down. I only get heat back if I turn it off and wait a little while and turn it back on and then it does the same thing... 10 seconds and i loose it again. this is the first 4.6 i have owned and i just got it yesterday 96 GT.

Any help is greatly appreciated.
Joe Liberto
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Plugged heater core will do that. Make sure your coolant level is ok first. Also the thermostat might be stuck open if the engine isn't reaching normal temperature. If those look ok, remove the heater hoses and flush the heater core with a garden hose, in both directions several times. You might find that you get heat after flushing the heater core, for only a few weeks, or months. If thats the case, you'll probably need to replace the heater core. If your coolant isn't clean and bright green, you should replace it. If It's really ugly, you should have the cooling system flushed as well as flushing the heater core separetly.
ok update... changed the thermostat... antifreeze is perfectly green level is ok the car is warming up good... another problem arose... when i put my blower motor on high... all the anitfreeze leaks out form this one spot in the firewall directly on my headers... its a valve or something thats right next to the tranny tunnel on the bottom left side right above the header and this just started to happen today so if i keep my blower motor off it doesnt leak... but it doesnt look like its threaded and it doesnt look like anything bolts up to it any ideas? i'll post a pic of it tomorrow if u guys dont know what i'm talking about

ADD: nevermind sometimes it does it when the blower motor is on sometimes it doesnt... i'm annoyed with trying to figure this out i'm taking it to a shop i'll let ya guys know how everything turns out
so i've been told that its the heater core... they said where its leaking from is what happens when the core gets clogged and needs replacing. so... 50 bucks for a heater core at my job and they said they'll put it in for $450 because its a 6 hour job (per what their book tells them) so what ever i'm not ****in taking my dash apart i'll let them do it and do it right