No heat from heater

[Z Ya Later]

Any idea what would cause this? I can feel a little heat when the car has been running for a while, but for the first minute or so AFTER the car has hit 180 deg. its cold. The A/C doesn't work either, so would they have the same culprit/fix? Thanks guys.

[azkkn]

Any idea what would cause this? I can feel a little heat when the car has been running for a while, but for the first minute or so AFTER the car has hit 180 deg. its cold. The A/C doesn't work either, so would they have the same culprit/fix? Thanks guys.

my old Z did the came thing, it was a 94. i changed the thermostat, and heater core to no avail, even the dealer couldnt tell me what was wrong

[Joe 1320]

Could be any of the diverters under the dash, The blower could also be losing it's effectiveness too. You'll have to take out the passenger side under dash parts to access the stuff. Check to see if the heater core gets warm, check the operation of the blower, etc. Could even be a loose vacuum line. hey, it's a start....

[azkkn]

Could be any of the diverters under the dash, The blower could also be losing it's effectiveness too. You'll have to take out the passenger side under dash parts to access the stuff. Check to see if the heater core gets warm, check the operation of the blower, etc. Could even be a loose vacuum line. hey, it's a start....

thinking about it more and having changed the entire dash fromt eh firewall out on my current Z, i would suggest putting it in the different positions in the flow control knob, and listening for the vaccume hiss. there are 5 or 6 vaccume lines on the back of that control know. if one isnt hooked up it wont work correctly. escecially where the a/c isnt working

[Hobbs95]

i have the same problem i had to drive about 30 miles to work in the morn and night and my heater never rose to comfort. i figured to check the heater core but i haven't started to look for it, is it hard to take out?

[Injuneer]

Heater core removal is a major project.... but you usually don't need to remove it unless it is leaking. It is common for them to sludge up. Remove the heater hoses (at the firewall, or at their origin), and use a garden hose to force clean water through the core.

[TraceZ]

Heater core removal is a major project.... but you usually don't need to remove it unless it is leaking. It is common for them to sludge up. Remove the heater hoses (at the firewall, or at their origin), and use a garden hose to force clean water through the core.

Nice Avatar Fred.

Also, if it is goop in the core that is blocking it up you should probably pressure flush the entire system really well, not just the heater core.

Generally speaking if the thermostat is working, the heater hoses are getting hot and free of obstruction then you should have a nice hot heater core. If you still dont have hot air in the cabin, it must me an air diverter or fan problem. Check the fan, vacuum hoses and flapper valves.

[Injuneer]

Nice Avatar Fred.....

Thanks! Someday there is going to be a version of that on my hood, in graphite "ghost" + silver highlights.

[Squat13]

Thanks! Someday there is going to be a version of that on my hood, in graphite "ghost" + silver highlights.

I did that to my TA. The Bird wasnt a Trans Am Birs but the Normanl Firebird with a extra outline here and there. It looks AWSOME . I recommend doing it because not many people have the screamin' chicken on a 4th gen. I have a picture at my moms house on her computer. I stop by on the way home and try to load it.

My TA was white so My bird was black

[95TransAm]

Thanks! Someday there is going to be a version of that on my hood, in graphite "ghost" + silver highlights.

That would look bada$$

[Z Ya Later]

Thanks for the help guys. I'm guessing its something to do with the vacuum lines, as I noticed earlier that if I switch it to the upper vents, I can feel air on the lower vents first for a few seconds to a couple minutes, then it switches. Also, I can feel a slight amount of air when it is supposed to be off. How hard is it to pull the dash apart? Does Rob (Shoebox) have a tutorial or would my Chilton's tell me? Thanks.

[fastTa]

Good advive so far. One other thing that commonly causes lack of heated air from the heter core is insufficient flow into the heater core from the water pump due to air pockets, steam pockets, or a water pump/thermostat going south..

Coolant flow to the heater core comes directly from the lower hose on the LT1 water pump. There should also be a flow restrictor in this hose that essentially regulates the pressure on the inlet of the heater core to prevent any damage to the heater core at high engine RPM's. The heater core outlet hose returns to the water pump at the upper hose connection, and also has a T-connector to the pressurized reservoir to bleed off any air. It is sometimes common for either of these passageways to become "gummed" up.

Like mentioned above a coolant system power flush would yield the best results, however you can remove the hoses I mentioned and clean them yourself.

Also perform a pressure check on the cooling system and cap and see if it is holding proper pressure just to be sure you are not getting air pockets into the system. The f-body LT1 cooling system should hold 16-18 psi.

[Hobbs95]

i haven't done a coolant flush since last year about this time i went on 7 long trips this summer and it ran cool. i check the coolant though and its turning brown i'll definetly do the coolant flush and if the heater core is plugged wouldn't one hose be hot and the other cold?
is there 2 air bleeder valves? i don't think i have air pockets but just in case

[REDxEYES]

Heater core removal is a major project.... but you usually don't need to remove it unless it is leaking. It is common for them to sludge up. Remove the heater hoses (at the firewall, or at their origin), and use a garden hose to force clean water through the core.

Ya I did that last night. Man, those two hoses seemed to be superglued on! I guess after being there 11 years what should I expect? Once I removed them, I followed your advice. It didn't semm to be to clogged, but I knew from them color of the fluid it wasn't very pretty. Let me tell you, putting the hoses back in their respective holes was easy, but those damn clamps were giving me a headache! I finally managed to get the left one on first and proceeded to the right one. OMFG! I finally got tired of it and sent my friend to Autozone to get an easier clamp. VOILA! Finally my car was providing Hell heat. Although I did notice this morning that it wasn't as hot but I need to flush the block.
Can I just pull off the thermo hose and the hose at the bottom of the waterpump and flush it that way?


BTW, I was very happy when I found this site! This is a great place! Thanks guys!

[Z Ya Later]

Alright, I'll get a power flush next week and see if that helps. If not, its into the dash I go...oy! lol