Just to add something into conversation about the build up in the reservoir. Mine had the same build up or scaling. When i put in my new radiator i pulled the tank and scrubbed it out best i could before flushing and refilling.Update. So maybe the reservoir has some of this stuck on the inside
Inside view
Outside engine passenger side video
https://youtu.be/QuaKeym89lY
Front side video
https://youtu.be/-tlSDmau8N8
Might be from the thermo
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