Car overheats with no signs of flowing liquid in upper or lower hoses. No signs of any leaks, and I've removed the thermostatic. Still no flow.
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1991 BMW 735iL
Answer #1ZeeTech October 19, 2010, 13:38Master
If there is no pressure and no circulation, it is a possible water pump problem.
Answer #2patrick mannion from Greg Solow's Engine Room, October 19, 2010, 20:28Master
Not sure if these cars have a plastic impeller on the water pump like other BMW, some Ford engines, some Jaguar and Audi/VW engines, The impeller fails and slips on the water pump shaft, car overheats and runs hot due to poor circulation. Call a local BMW specialty shop and ask them have they seen the water pumps fail on that model/year, they may say "sure we see it all the time!"