I broke it, but how? Cooling and Heater Problem
02-11-12, 08:35 PM
#1
I broke it, but how? Cooling and Heater Problem
Hi there, My name is Donny and I have red hair, hence my fourm name.
Today I warmed my car up, an 86 GXL FC daily driver and proceeded to exit my neighbrohood through the snow with two people pushing me. They bent my antennaa, but I was out. I was on the way to pick up my baby Sun Conure in Harrisburg. Being warm already and having to turn the tires through the snow caused some overheating, so much so that my overflow tub lid popped off with about .5 Gallon of delicious Coolant. No biggie, filled her up, while i let it cool, it was 20 degrees out up here in Pittsburgh. The buzzer and ADD COOLANT went off in the HUD so I performed a quick air bleed of the system. The buzzer and light subsided.
Right about the time I got on the Turnpike I realized I was frozen, and my heat was cold. The flapper is not making a noticable thud when I toggle between Hot and Cold. I turn back, no way a 4 oz parrot will make it in a Mazda sports car with no heat, simply to many drafts. I was on the road for about 1.5 hours with no engine temp issues, the reading is normal on it. I do understand how inaccurate these are so I was quite worried.
I jump on my favorite site for troubleshooting (This one) and start searching the archives. I replace the Thermostat (Stant is all i could pick up, has a jiggler).
It's just stuck open so my engine is OVERCOOLING right? Well I changed it, and drove for 25 mins and still it was a No-Go. My replacement work was alittle messy as it was snowing and blowing, I had to use the original gasket. I supplemented my install with some cooling system RTV. As Im writing this I worry that I was supposed to put rtv under the thermo too? Shoot, I have to look at that...
Tomorrow I guess I will be ripping out my logicon to test the 17-pin connector for voltage and res. at the "Flapper Motor". Apparently there is a 18 in cable comming out of it and the connector is a chore to get to and right now my garage is the grocery store parking lot nearby. Before I do this I thought to run it by the collective members.
Is it possible that there is still air in the system yet my buzzer and light are not comming on?
I doubt that when my heater worked before i overheated, than failed 20 minutes later after getting pretty warm (Not quite to the top but up there) not has anything to do with cold solder joints.
I have had a small leak of coolant in the past, but was never an issue. The cooling seals have not been compomised prior and I did a system flush about a year ago along with ALL the other fluids. I've taken these cars all the way apart and have repaired my younger brother (I got him hooked) and other friends problems with them (All my friends had RX7's, well the cool ones
so technical troubleshooting is welcome. Thank you for your time guys!
-Donny
On a sidenote I pulled this off another site. Because today it was Much colder than it has been yet this year I am considering what this Mike guy is saying about the Mix Motors.
"Cold Solder points in the Logicon (Mike Mario)
I have repaired my logicon because my heater didn't maintain the correct temp. It would stay hot for a while and then the air mix motor would move the vent settings to the cold position. It would generally stay in that position. There is also another well known problem with the air mix adjust motors. They were manufactured with an inappropriate lubricant, which causes the motor to seize in low temperature environments. This can burn out the drive transistors in the logicon and possibly the motor itself."
Today I warmed my car up, an 86 GXL FC daily driver and proceeded to exit my neighbrohood through the snow with two people pushing me. They bent my antennaa, but I was out. I was on the way to pick up my baby Sun Conure in Harrisburg. Being warm already and having to turn the tires through the snow caused some overheating, so much so that my overflow tub lid popped off with about .5 Gallon of delicious Coolant. No biggie, filled her up, while i let it cool, it was 20 degrees out up here in Pittsburgh. The buzzer and ADD COOLANT went off in the HUD so I performed a quick air bleed of the system. The buzzer and light subsided.
Right about the time I got on the Turnpike I realized I was frozen, and my heat was cold. The flapper is not making a noticable thud when I toggle between Hot and Cold. I turn back, no way a 4 oz parrot will make it in a Mazda sports car with no heat, simply to many drafts. I was on the road for about 1.5 hours with no engine temp issues, the reading is normal on it. I do understand how inaccurate these are so I was quite worried.
I jump on my favorite site for troubleshooting (This one) and start searching the archives. I replace the Thermostat (Stant is all i could pick up, has a jiggler).
It's just stuck open so my engine is OVERCOOLING right? Well I changed it, and drove for 25 mins and still it was a No-Go. My replacement work was alittle messy as it was snowing and blowing, I had to use the original gasket. I supplemented my install with some cooling system RTV. As Im writing this I worry that I was supposed to put rtv under the thermo too? Shoot, I have to look at that...
Tomorrow I guess I will be ripping out my logicon to test the 17-pin connector for voltage and res. at the "Flapper Motor". Apparently there is a 18 in cable comming out of it and the connector is a chore to get to and right now my garage is the grocery store parking lot nearby. Before I do this I thought to run it by the collective members.
Is it possible that there is still air in the system yet my buzzer and light are not comming on?
I doubt that when my heater worked before i overheated, than failed 20 minutes later after getting pretty warm (Not quite to the top but up there) not has anything to do with cold solder joints.
I have had a small leak of coolant in the past, but was never an issue. The cooling seals have not been compomised prior and I did a system flush about a year ago along with ALL the other fluids. I've taken these cars all the way apart and have repaired my younger brother (I got him hooked) and other friends problems with them (All my friends had RX7's, well the cool ones
so technical troubleshooting is welcome. Thank you for your time guys! -Donny
On a sidenote I pulled this off another site. Because today it was Much colder than it has been yet this year I am considering what this Mike guy is saying about the Mix Motors.
"Cold Solder points in the Logicon (Mike Mario)
I have repaired my logicon because my heater didn't maintain the correct temp. It would stay hot for a while and then the air mix motor would move the vent settings to the cold position. It would generally stay in that position. There is also another well known problem with the air mix adjust motors. They were manufactured with an inappropriate lubricant, which causes the motor to seize in low temperature environments. This can burn out the drive transistors in the logicon and possibly the motor itself."
02-12-12, 10:15 AM
#3
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Your problem most likely is the Stant thermostat. There is a write up on here in the 2nd gen section that explains the problems with them. They suck, I had one in my 86 GXL, my 1st FC, and blew the coolant seals a week after I went to a Stant.
04-03-12, 12:02 PM
#7
I replaced the stant with an OEM from Mazda, flushed out my system, and found parts of rubber gasketing in the small 1/4 in tube going from the filler neck to the rad. that seems to be from when the original owner replaced the water pump.
I also bought a new fan clutch, it works better but I am still overheating at times at idle. My idle is almost at 750.
When stopped and at idle my 13b is giggitying, with small bumps that seem to throw it off balance. Its not severe, but my timing may be off. I have a good smooth acceleration throughout to redline though. I read that timing may cause an overheat? when my gauge gets halfway I shut it off but two or three times I pulled into my driveway with a boiling engine. I am about to put my old thermo in, or take it out alltogether to see how it runs then.
It cools down much faster when I go from traffic and get to 35ish but still at idle it climbs. I tried to use a timing light, but the thing would not light up. Anyone in pittsburgh have a light I can borrow?
I also bought a new fan clutch, it works better but I am still overheating at times at idle. My idle is almost at 750.
When stopped and at idle my 13b is giggitying, with small bumps that seem to throw it off balance. Its not severe, but my timing may be off. I have a good smooth acceleration throughout to redline though. I read that timing may cause an overheat? when my gauge gets halfway I shut it off but two or three times I pulled into my driveway with a boiling engine. I am about to put my old thermo in, or take it out alltogether to see how it runs then.
It cools down much faster when I go from traffic and get to 35ish but still at idle it climbs. I tried to use a timing light, but the thing would not light up. Anyone in pittsburgh have a light I can borrow?
Last edited by Reddon; 04-03-12 at 12:04 PM. Reason: I forgot to mention, I bypassed my heater core, it will only flow in reverse. Can I hook it up in reverse?
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