if my thermostat were clogged- would it be noticeable on the top 2 openings or on the bottom? I've got the top 2 hoses off and the thing looks pristine....Thanks for the help

 

The small holes visible from the top are the sensor holes that allow coolant from the hot engine to get to the heat-sensitive side of the thermostat. Once the coolant below the thermostat gets warm enough, the thermostat opens and then coolant flows from the bottom of the radiator up through the open center of the thermostat. So, if it isn't opening it would be caused by blocked sensor holes which you could see from above. If it is clogged from scale and debris and the coolant can't flow throuugh it, that would be seen from the bottom. However, I seriously doubt that can happen. But since your are just one clamp away from knowing, why not check it out? Also might be a good time to switch to a 180 degree thermostat too.

 

Thanks for the speedy answer pal! getting that bottome clamp off is a beast! HA

 

haha ya, I changed out all my coolant hoses a couple months back and some were pretty difficult.

As mentioned above, switch to a 180 thermo and also get some screw type clamps. They are much easier to work with to get on and off.

 

re: then coolant flows from the bottom of the radiator up through the open center of the thermostat.

Just to add to this, up through the open part of the thermostat, through the mixing chamber, and out the side arm port on the double walled body, to the water pump. The stat, when open, jams that little disc with the holes closed, so just the sample water can flow. If the main stat is closed, like on a cold morning, the top disk can move out of the way by the soft spring, and allow more heat buildup in the heater core for those whose butts are frozen to the seat. The 180F stat is one of the best upgrades out there.