Our Community is 940,000 Strong. Join Us.

1972 Charger Thermostat

09-19-2017, 03:01 PM
How would I go about replacing the thermostat on a 318 engine on my 72 charger?

Dave B.
10-10-2017, 04:01 AM
First, it's a good idea to drain some coolant from the system. One or two quarts should do it. There's usually a little valve (called a 'petcock') down low on one side of the radiator. It looks a bit like a flat wingnut. Put a BIG pan under the car below the petcock because the flow of coolant is somewhat unpredictable. The reason you're draining the coolant is that the level of coolant in the radiator is usually higher than that in the engine and it will flood out while you're working on the thermostat...
Next, trace the upper radiator hose from the radiator back to the intake manifold on the engine.
At that point, you'll find a rounded metal thermostat housing bolted to the intake manifold. It's usually a good idea to loosen the clamp and separate the upper hose from the thermostat housing at this time.
Next, remove the two bolts securing the housing and lift it straight up. You may have to pry gently around the edge, as there's usually sealant there.
Remove the old gasket completely, gently scraping the mating surfaces as required. The round part inside is the thermostat. Be sure to take note that there is usually a 'pointed' side that sticks up.
Using paper towels or something similar, make sure that the mating surfaces are clean and dry.
Install the new thermostat in the manifold, replace the gasket and the thermostat housing, then re-install the two bolts. Before doing this, you may want to add a THIN coating of sealant on the new gasket for insurance.
Warning: Thermostat housings are usually made of cast aluminum or pot-metal and are VERY easy to crack/break!! If you have access to a torque wrench, be sure to tighten the bolts evenly, moving back and forth from one to the other in small steps. Torque settings can be found on the internet. If you don't have a torque wrench, tighten the bolts evenly and securely, but don't go overboard pulling on the wrench!
Re-install the radiator hose, start the car and refill the radiator - you're finished!

Add your comment to this topic!