The loose rivet (jiggle pin) is an air vent. This allows the air to be purged out of the system and the T-stat to function properly.

Orient the rivet to the upright position so it is lined up with a protrusion on the water inlet cover. Look for this protrusion on the outside of the flange of the cover that mates up against the water inlet housing.

 

Last night my dad came over to help with this car. He said as long as it does not get in the red, it is fine. Before the temp gauge on the dash hit the red last night, the fans kicked on.

Dad says this is alright, but it makes me uncomfortable. I have never had this car creep up on the gauge that high. It would always stay at he mid-level point.

It currently has the new toyota t-stat in. I did not get a chance to see what would happen with the original.

What are your thoughts?

 

The temp gauge needle should remain in the same place and not rise up and down. Typically mid gauge or slightly lower.

Is the bottom hose still cool compared to the top?

 

The bottom hose ended up being pretty hot after I let it get right below the red line, the fans came on, but only for a moment.

 

Check the fan switch for proper operation.

Should turn OFF at around 199F and ON at around 186F. The switch works opposite of what you would expect.

 

I installed a new fan switch and this did not help.

How should the t-stat be seated back into the housing? Should it be suctioned into the engine part, or does this happen on its own?

When I took out the original t-stat, it was tight within the part that was on the side of the engine.

Could this be the cause?

 

Typically the T-stat has a rubber U-shaped gasket that installs around the T-stat flange. Once installed, the T-stat and gasket are pushed into the water pump inlet housing. The gasket seals between the T-stat and housing. The rivet on the flange is aligned with a protrusion sticking out of the inlet housing. When aligned the rivet will be oriented at the top of the T-stat.

Once the inlet housing is installed T-stat should be held captive by the gasket and not move.