I had noticed some grinding when I first started the engine, but it went away too quickly to identify. But after a few drives, I noticed (despite the coolant gauge showing low-peg) that the coolant was boiling, even after short drives. When I checked the radiator, it was always cold, even when the engine was hot. And even when the t'stat cover was hot, there was no flow - not even through the heater core, which showed that the pump wasn't moving any coolant. When I remove it, I found a bore plug (apparently knocked in by the previous owner who had installed the RUBBER plugs) had worked its way through the water jacket to the pump, and become friction-welded to the impeller (which was now stopped, with the pump shaft spinning in it). After installing a new pump, the radiator gets hot all the way to the bottom, showing that there is no substantial blockage inside it. The engine runs perfectly now.
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![waterpumpimpeller.jpg I had noticed some grinding when I first started the engine, but it went away too quickly to identify. But after a few drives, I noticed (despite the coolant gauge showing low-peg) that the coolant was boiling, even after short drives. When I checked the radiator, it was always cold, even when the engine was hot. And even when the t'stat cover was hot, there was no flow - not even through the heater core, which showed that the pump wasn't moving any coolant. When I remove it, I found a bore plug (apparently knocked in by the previous owner who had installed the RUBBER plugs) had worked its way through the water jacket to the pump, and become friction-welded to the impeller (which was now stopped, with the pump shaft spinning in it). After installing a new pump, the radiator gets hot all the way to the bottom, showing that there is no substantial blockage inside it. The engine runs perfectly now.
[url=https://www.supermotors.net/vehicles/registry/media/1163985][img]https://www.supermotors.net/getfile/1163985/thumbnail/20210103_150315.jpg[/img][/url] . [url=https://www.supermotors.net/registry/media/173189][img]https://www.supermotors.net/getfile/173189/thumbnail/23-waterpump.jpg[/img][/url] . [url=https://www.supermotors.net/registry/media/1142745][img]https://www.supermotors.net/getfile/1142745/thumbnail/coolantneglect.jpg[/img][/url]](https://www.supermotors.net/getfile/1163713/fullsize/waterpumpimpeller.jpg)