AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
- Jan 19, 2014
- Messages
- 24,929
- Reaction score
- 12,278
Well lets try this
The pump is really good at circulating pure liquid.
The thermostat is pretty good at sensing liquid temperature, and really lousy at sensing air temperature.
The first sign of trouble was the no heat in the cab. Thats a sure sign of the water not circulating in the heater core which almost always is a low liquid level in the system. The heater always warns you.
The pump is not too good at pumping a water/air mixture, especially at slow speeds.
So if the system has or develops air in it, the first thing that happens is the stat closes up. And the pump, at slow speeds, ends up just mixing the slurry around, occasionally bouncing it up against the stat, as rpm allows. Of course the stat is slow as cold molasses to respond, so things just get hotter and hotter. Then that hi-pressure cap isnt helping, and eventually the steam just blows stuff up. And the worst of it is that the temp gauge is lying to you, telling you everything is fine because its NOT sitting in the water. And if the issue is a head gasket, then the steam pressure blows water out, maybe into the cylinders, and things just get worse and worse.Or if the issue is a failed water pump, you can have similar issues.
-There are three things you can do that will extend your diagnostic time and reduce the risk of bodily harm; 1) install straight water with the additive pkg, 2) swap out that stat for a restrictor washer, and 3) get rid of that hi-pressure cap.
-With the washer in there the pump wont cavitate and the water will continue to circulate.And if the pump is good, you will instantly be able to prove it by observing the liquid in the filler neck. The water will get rid of heat way faster than any other coolant. The additive pkg will protect your pump seal. And the lack of pressure will reduce the loss of liquid to a minimum, and the destruction of old or soft parts.
-Oh but you say the water boils at 212 now, a lower temp than with the pressure cap. I cant argue that. But heres the deal with that; Id rather be bending over the fender with an open system thats giving me plenty of warning as to when its gonna boil, than with a pressurized system that could blow at any moment, sending me to the hospital.
-Oh but you say, I have no freeze protection now. Thats true so dont leave it outside after youve diagnosed it.After youve diagnosed and repaired the system, you can return the coolant and stat as you like.
FWIW; In Manitoba, I have never run more than a 7 pound cap, and run straight water with the A-pkg, all summer. All my system is 15 years old, is in fine condition, and works 100%.
The pump is really good at circulating pure liquid.
The thermostat is pretty good at sensing liquid temperature, and really lousy at sensing air temperature.
The first sign of trouble was the no heat in the cab. Thats a sure sign of the water not circulating in the heater core which almost always is a low liquid level in the system. The heater always warns you.
The pump is not too good at pumping a water/air mixture, especially at slow speeds.
So if the system has or develops air in it, the first thing that happens is the stat closes up. And the pump, at slow speeds, ends up just mixing the slurry around, occasionally bouncing it up against the stat, as rpm allows. Of course the stat is slow as cold molasses to respond, so things just get hotter and hotter. Then that hi-pressure cap isnt helping, and eventually the steam just blows stuff up. And the worst of it is that the temp gauge is lying to you, telling you everything is fine because its NOT sitting in the water. And if the issue is a head gasket, then the steam pressure blows water out, maybe into the cylinders, and things just get worse and worse.Or if the issue is a failed water pump, you can have similar issues.
-There are three things you can do that will extend your diagnostic time and reduce the risk of bodily harm; 1) install straight water with the additive pkg, 2) swap out that stat for a restrictor washer, and 3) get rid of that hi-pressure cap.
-With the washer in there the pump wont cavitate and the water will continue to circulate.And if the pump is good, you will instantly be able to prove it by observing the liquid in the filler neck. The water will get rid of heat way faster than any other coolant. The additive pkg will protect your pump seal. And the lack of pressure will reduce the loss of liquid to a minimum, and the destruction of old or soft parts.
-Oh but you say the water boils at 212 now, a lower temp than with the pressure cap. I cant argue that. But heres the deal with that; Id rather be bending over the fender with an open system thats giving me plenty of warning as to when its gonna boil, than with a pressurized system that could blow at any moment, sending me to the hospital.
-Oh but you say, I have no freeze protection now. Thats true so dont leave it outside after youve diagnosed it.After youve diagnosed and repaired the system, you can return the coolant and stat as you like.
FWIW; In Manitoba, I have never run more than a 7 pound cap, and run straight water with the A-pkg, all summer. All my system is 15 years old, is in fine condition, and works 100%.
