Done! No effect unfortunately. Here are some photos:


The unit I used...



Old thermostat removed. The inside of thermostat housing looks pretty clean. Coolant drained from the radiator clear and bright.



Kind of hard to see, but here is a picture of me fishing a straight pick thru the bleed passage in the thermostat housing to show that it is not blocked.



New unit installed. Arrow pointing upwards, spring side towards the block.




End result:



I am flummoxed. A few questions:

• I appear to have weak heat as well. With the heat on, engine temps are slightly lower. Can this be related?
• Should there be air in the radiator top hose at all at hot idle?
• Should you be able to feel water flowing thru the top hose when the engine is hot?
• Is my next step tearing apart the thermostat housing and water pump housing to find the restriction?

Any advice is welcome!