Holy moly, temp temp temp

[kawahonda]

Thanks! I will check the bottom hose for collapsing. I can say without a doubt the top hose isn't collapsing, but didn't check bottom. I'll check all this stuff today/tomorrow and report back...

Have a car show in 2 weeks....

[kawahonda]

K, some more findings. I shot the temp IR on the manifold right next to the temp sender.

I let it idle in the garage. It would not leave a little less than halfway on the gauge with it idling in the garage.  Garage was 83.

A little less than halfway on the gauge is about 186F on the temp sender. There was some water moving for sure, but it wasn't like.....heavily moving.

I'm guessing the middle of the gauge is about 192-194ish.

I drove about 7 miles, 40 MPH average speed. Towards the end when I got home, the attached photo is where I got to, which is basically 208F at the temp sender on the manifold.

The bottom hose already has a coil in it. The hoses are not collapsing.

I lifted up on the radiator cap for a brief microsecond. I notice a "gulping" sound at the t-stat housing that would "glup" every few seconds after I did that. I show a video of that. May be normal behavior?

I'm hoping a new T-stat is all I need. I haven't shot the IR on my radiator yet.

[kawahonda]

Here's the water movement at 193F (taken with IR near the temp sender).

[kawahonda]

Here's the "burping" sound.

https://youtu.be/4wKfmuIwvb4

[70 Challenger Lover]

I'd say a little less than half on the gauge would be your goal then if that's 185ish. The water flow looked pretty good from what I could see. The gurgling sound is probably water percolating inside. Definitely hot.

Seems like thermostat would be a good starting point. What I started doing on new thermostats is drilling a small weep hole on the outer rung just to let air bleed out when refilling it. Not sure on small blocks but maybe it's not all that necessary since they have a bypass.

[kawahonda]

I will also say that the heater blows hot air if I ask it to!

But yes, something changed or is failing.

[Chryco Psycho]

"gulping" sound is the water boiling my bet is the thermostat is stuck closed

[kawahonda]

I bet the thermostat is going to look like complete $hit when I remove it soon...

That t stat is easily 20 years old.

[Chryco Psycho]

It will probably run away when you pull it as it will be so happy to be out of there !!

[kawahonda]

Here you go.

[Chryco Psycho]

Doesn't look bad but that means nothing

[kawahonda]

It's a vintage piece for sure!

Doing a boil test.

[Chryco Psycho]

good plan , but I would still replace it !!

[kawahonda]

192F it was partially open....10% cracked open at best....maybe 5%.

Fully open at 202-203F.

Seems like a faulty thermostat to me. It's rated at 180F.

But then again google sez: "It is fully open about 15-20 degrees above its rated temperature. If the temperature of the circulating coolant begins to drop, the wax element contracts, allowing spring tension to close the thermostat, thus decreasing coolant flow through the radiator."

[Chryco Psycho]

was the clutch fan tight when it was warm today or did you check ?