So i am in the process of changing heads due to broken spark plug. So i figured I would go ahead and change the thermostat so I won’t have to do it later down the road. When i took of the thermostat housing these white chunks come falling out in the hose side of the housing. Also, this is on a 2004 dodge ram 1500 4.7 with 145,000 miles.

 

Looks like a good reason to do a thorough flush and fill on the cooling system.....

How about a pic with something for scale?

 

I'll bet the coolant hasn't been kept up properly. If tap water has been used to mix coolant rather than distilled, the tap water had a high calcium content. (Hard water.) Sort of like gall stones. A good flush like HeyYou said should help out cooling. A lot easier than getting your gall bladder out.

 

I also thought it was something with the water... if it turns white you know the coolant needs to flushed.