I can't figure out why the heat isn't working in an 1986 Audi 5000s.
I've backflushed the cooling system and checked for blockages; everything is okay.
I noticed however that if I disconnect the coolant hose at the back of the engine block while the car is running, no coolant rushes out. Also the return pipe from the radiator core doesn't get hot.
I would suspect a bad water pump, but the engine doesn't overheat, and the radiator gets properly hot.
Any ideas out there before I pull the water pump just to make sure that's not the problem?
Regards,
Worth Winslow