Does anyone happen to know how hot the heater blows? My heater doesn't work very well. 86 GT 1998 3800 sc. With the vent on: 67 degrees ambient in the car 77 deg at vent by door 80 deg at center vent
with heater on: 76 deg at vent by door
coolant temp was 185 deg temperature in the garage was 44 deg.
The car would never overheat, but would get hot in the summer, so I'm not sure if there is some other plumbing issue. I've burped the coolant. I've read many threads on how to add coolant to a 3800 swap with 3800 t-stat and followed the instructions.
Edit: Heater core is fairly new as well.
[This message has been edited by bomluuk (edited 01-02-2015).]
First See my Cave, Heater cover items that affect all engines.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
The heater core uses coolant at operating temperature.....so 220*F is typical. If it is not flowing well, you get less heat. Yours may be 90% blocked either by an air bubble or something solid.
[This message has been edited by Gall757 (edited 01-02-2015).]
Check the cable from the HVAC control head to the lever on the plenum under the dash. The lever/cable controls the positioning of the 'BLEND' door. Sometimes the clamp loosens and the door will not close completely.
Originally posted by olejoedad: Check the cable from the HVAC control head to the lever on the plenum under the dash. The lever/cable controls the positioning of the 'BLEND' door. Sometimes the clamp loosens and the door will not close completely.
that and/or heater/AC plenum is full of leaves etc blocking air flow. That can cause fires because the control resistors gets very hot.
I had a heater issue with my '86 GT with 3800SC. The heater hoses were not routed properly. Both were connected to coolant return circuits so my coolant flow was basically nonexistent. Got them hooked up right and now blows hot air on heat.
Mine ran like yours, until I noticed a small leak in the radiator, which caused air getting into the system. I replaced the radiator, hoses, water pump and heater core (they were all so cheap, so may as well get them all at once). I then had mine to 95* from the center vents, at full blast. It ran around 92* on the 3rd fan speed. This is with Vent at full hot.
After that, I had a small leak develop from the radiator to overfill tank hose (it was a cheap Prestone hose), putting an air bubble back into the system, so the heater ran cooler. Replaced it with a much beefier hose and it's back to 95*. Get rid of the air bubbles in the system and it should be okay again.
I followed Orgre's instructions of burping the coolant system, but leaving the thermostat in did not work for me. I removed the thermostat during the process, while the car was started up cold, so the coolant could circulate and it worked.
PS. I was wondering if I could do better than 95*, if anyone knows? Just curious
[This message has been edited by MacGyversMullet (edited 01-03-2015).]
I had a heater issue with my '86 GT with 3800SC. The heater hoses were not routed properly. Both were connected to coolant return circuits so my coolant flow was basically nonexistent. Got them hooked up right and now blows hot air on heat.
I had a heater issue with my '86 GT with 3800SC. The heater hoses were not routed properly. Both were connected to coolant return circuits so my coolant flow was basically nonexistent. Got them hooked up right and now blows hot air on heat.
I guess that you could say both. The 3800 thermostat and thermo housing are still on the engine. From that housing a short section of radiator hose connects to a modified Fiero thermostat housing, however, there is no thermostat in that modified housing. It just provides a filler location that it higher than the rest of the cooling system. FYI, I also installed an electric temperature gauge by inserting the sending unit into the small threaded opening on top of the 3800 thermo housing. Works great.
