Burped air but no coolant circulating.Pump looks intact, no noises, leaks, impeller is intact. Could water pump seem good but have impeller spinning on shaft?
Overheating,no leaks,new thermostat, water pump good, no coolant circulating. on 1997 Volkswagen Cabrio
Has the water pump been off to actually inspect the impeller? If there is no flow detected , even with thermostat removed , your options are kind of limited.
Yes, removed water pump and it actually looks fairly new, I had read a post where someone mentioned impeller could be loose and not spinning as it should, belt is tight. Has anyone else heard of this? Thermostat has been replaced with new one.Might just have to remove water pump again and check.
Years(actually decades) ago , When TRW had just started making NEW water pumps , the shop I worked at decided to give them a shot and the first one , yes , the impeller simply came off the shaft within seconds of start-up , the second one (for a different car , came apart externally and destroyed the radiator along with a few other important items. So , yeah , weird things happen. Keep monitoring conditions and , might I go 'old school' on you and say---Luke, use the force---You know what SHOULD be happening , list what IS working right , and go backwards?
Having never wrenched on one of these I felt there's a group of German engineers laughing at the thought of someone replacing water pump and even harder at doing it twice, I didn't take pump I bought back yet and now that I've accepted that even if the old one seemed good it needs replacing. Thanks for sharing.