74 AMX Thermastat

1. Remove the radiator cap and drain the coolant either at the petcock of the radiator (simple and clean) or by pulling the lower radiator hoe (fast but messy).

2. Follow the upper radiator hose to the aluminum housing on the intake manifold as mentioned before.

3. Remove the upper hose.

4. Remove the two bolts that hold the thermostat housing and remove the housing and thermostat.

5. Clean all surfaces including the step in the intake where the thermostat sits.

6. Install the new thermostat with the frame of the thermostat that looks almost like an arrow pointing towards the hose not down into the intake manifold. This is critical.

7. Install the housing and gasket. I always use a little right stuff on the gasket.

8. Install upper hose and close the petcock or install the lower hose.

9. Inspect the radiator core and cap. I replace the cap with every thermostat since they weaken over time. Never reuse coolant.

10. If everything looks good, fill the radiator with the correct amount of coolant/water mix. Let it sit for a bit and keep adding until the level doesn't drop.

11. Start the car with the cap off and turn the heater on hot, high fan, on defrost. This will burp air out of the beater core.

12. Run the car until the heater is blowing hot and the thermostat opens allowing hot water to flow through the upper hose into the radiator. Keep the system topped off. I will frequently massage the radiator hoses and heater hoses to aid in circulation and burping of air. The heater hoses should heat up before the thermostat opens so feeling the heater hoses is a good way to determine pump circulation and air in the system.

13. Once the car reaches operating temp it will start to push coolant out the radiator, top it off and put the cap on before it gushes hot water everywhere.

14. Make sure temp stabilizes and heater still blows hot.

Done.

As for the rest of the questions, they aren't unfounded either. When is it overheating? Does it boil over or just get hotter than normal? What kind of fan are you running? Does it have a fan shroud? If it's not leaking out the weep hole in the water pump, that's not a likely cause. I have had a rash of bad radiator caps the last couple years so I just replace them every time I replace anything in the cooling system. Etc etc etc. I just had to flush my entire system, replace all 4 thermostats, and replace the electric fan clutch on my truck due to an overheating issue. Few things are as annoying. If the new coolant, cap, and thermostat doesn't cure it, and the fan system is functioning correctly with an effective shroud, and the radiator is clean inside, I would get it pressure tested or have a combustion test done on the cooling system.