Stuck thermostat?

[MoparDan]

Engine was overheating, while sitting in a long line...anti freeze was pouring out the overflow bottle, like the thermostat was sticking I just replaced the thermostat about a month ago, is the thermostat defective or something else?

 

[69-]

Hard to say.

You can test the thermostat in a pot with boiling water, it has to fully open.

 

[MoparDan]

How would I know?

 

[69-]

Take the thermostat out, it will be closed. Put it in a pot with boiling water and it will open. You will see the closing plate to open.

 

[69-]

If it does open, there's most likely lots of dirt, grime and such in the cooling system.

I'd then suggest to flush the whole system.

Else it could (I'd say unlikely) be the water pump. If you take the belt off, the fan (it is connected to the impeller inside) should turn very easily.

 

[69-]

Or you have a visco coupled fan, then it should have some resistance while the belt is on. Visco coupling is heat actuated and fully turns the fan only when hot. Water pump is meanwhile always turned by the belt.

 

[69-]

You from Daytona beach? Man, I completely missed taking that into account when I was at the Rolex 24h in January...

 

[MoparDan]

Take the thermostat out, it will be closed. Put it in a pot with boiling water and it will open. You will see the closing plate to open.

As soon as I get my sockets back tonight I'll do that...

You from Daytona beach? Man, I completely missed taking that into account when I was at the Rolex 24h in January...

Yah, lived here about 9 years now

 

[MoparDan]

Seems to be seepage around the housing

 

[AMC Diplomat]

My guesses are air trapped in the system... or your fan clutch is junk and you legitimately overheated

 

[MoparDan]

The good news is the oil isn't milky so that's a good sign at least. I found it strange that the temperature gauge was climbing since it pretty much doesn't move anymore, that's when I popped the hood and saw a ton of coolant pouring out the bottle like the last time it stuck

 

[AMC Diplomat]

Yeah I'm going with bad fan clutch. The rest of my parts cannon theory of automotive repair would go like this: Bad radiator cap. Then clogged radiator. Then bad water pump. Then time for new engine.