no heat

[a_turbo_stang]

Hey all on my 90 GT drive it today for the first time since it has been cold and it has no heat. It will blow mildly warm air at an idle but once you start moving you can forget about heat. I am thinking heater core. Would that be a safe guess? Or should I look at something else first? Any help would be great. Thanks

 

[mstangracer]

anyone ? i have the same problem but it think having no a/c and a 180 t stat won't let the car get that warm in the cold weather

 

[Jerry Leaming]

Check and see how hot the hoses are going to the heater core.
If there are the same or close to the same temp as the radiator hoses. Then maybe a stuck air valve for the heating system the valve that switches the duct from cold to hot or vise versa.?
If not maybe a plugged heater core.?

Just guessin........

 

[a_turbo_stang]

How can you check to see if it is the air valve?

 

[IndyBlk5.0]

it can be a lot of things, i had a leaky heater core and it smelled sweet like antifreeze when i turned on my heat. Also, i had a 160 thermostat in there and it wasnt hot enough to blow hot, i put a stock 194 stat in there and it runs me out of the car. Me and 5.0droptop replaced the heater core. Another problem COULD be a head gasket, mine went out and i would have heat sometimes and other times nothing.. My system was pressurizing and blowing out of the resevoir when i got on it hard a few times... doesnt sound like the problem.. check coolant level, thermostat, and if you dont find anything, then i would say heater core. could be air in the system also.

 

[a_turbo_stang]

Yea hopefully it isnt head gasket i only have 30K on motor. But I do smell a lil antifreeze when I turn heat on high. But I do not see any leaks and the coolant level is full. I got a buddy that says he can replace a heater core in lil over an hour. I am not sure how hard they are to do, never had to do one. It is on a 90 GT. Thanks for the info.

 

[speedytang]

For 3 years I have had no heat since I went to a large radiator and my radiator even had a sticker on it warning that if used with fuel injection that it may still be in cold loop. I have a 192 degree thermostat and if it opens as soon as I turn on the blower it cools the heating core and I freeze. The only way I can get heat is remove the mechanical fan and block the radiator with a plexiglass cover for the radiator if it gets 20 degrees or cooler and then my car warms up and stays warm even when moving. I guess I need to install a electric fan.

 

[Black Sun 5.0]

How are your fluid levels in the car? If you're leaking coolant and are running low, you will lose heat. Maybe the core or a passageway is clogged and you should flush the cooling system. What is the engine temp. going to?

 

[a_turbo_stang]

The coolant level is fine. It does not drop. I have a 3 core radiator in it. The eng. temp runs halfway on the stock gauge.

 

[speedytang]

If the car has air condition the heater core is about a 4-6 hour job if done before so you can find the hidden bolts. With out air it is a 20 min. job

 

[a_turbo_stang]

If the car has air condition the heater core is about a 4-6 hour job if done before so you can find the hidden bolts. With out air it is a 20 min. job

Nope got air Why is with air so hard? Looks like I will be finding out tonight. The hole dash does not need to come out does it? I replaced one in a 86 it took a lil over an hour and it had air. But the dash is different from the 87+ models.

 

[speedytang]

You will be removing the center console and dash to get the air box out from the firewall.

 

[AUBURN1111]

what about the long plastic vacuum line that runs along the engine side of the fire wall, Ive seen those cracked before and not letting AC or heat work at full potential.

 

[Black 93 Fox]

Sounds like a real bitch of a problem not being able to be warm in the winter. What i have to say as already been said so i'll give ya a bump.

Black93fox

 

[slick88GT]

If the car has air condition the heater core is about a 4-6 hour job if done before so you can find the hidden bolts. With out air it is a 20 min. job

20 min?? Are you nuts?? Having air adds like an extra 30 minutes as opposed to a car that doesnt have air. It has nothing to do with hidden bolts, just a pain to work around the AC lines. I have an 88 with AC and did 2 cores without even disconnecting the lines and losing freon. First time took me 3.5 hours, 2nd time took me 2.5 hours. I did one in a friend's 88 without AC and it took me 2 hours. 86 you get to through the glove box, 87-93 you are screwed and have to pull the dash halfway out. It sux man. I ripped my AC out so next time it will be slightly easier. Oh, dont buy an autozone core or else you'll be doing it again in a year like I had to do