The garage told me my water pump was pumping quot;weaklyand needs to be replaced.
Yes you can have a weak pump. They wear out after awhile. but before replacing the pump, make sure that you don't have any blockage in you hoses. A partially blocked hose can make it appear like your pump is not working well and cleaning a hose out is a lot cheaper then replacing the pump.
You got one of the money making shops. If you go for this they will give you a BIG bill and you will have the same water pump. Water pumps go bad when the mechanical seal fails and they leak. No other reason ---if it ain't leakin it ain't bad. The only way you could have a weak' pump would be a slipping belt and that would create an overheat problem. I don't know if you have a heating problem but if you ever do go to a RADIATOR SHOP not a rip off auto repair. Don't fall for the thermostat thing either--same scenario big bill--- same thermostat. Water pumps and thermostats don't cause overheat problems except in extremely rare situations.
Good question (finally). It will pump weakly if it is not turning fast enough or is leaking at a seal. If you have a faulty belt that is slipping it will not turn fast enough. Go to another mechanic.
It is very seldom that a water pump will work weakly as you put it. In order forthe pump to work at less than capacity, the impellers would have to be worn out, and that is not likely. Usually the shaft bearingwill be the first thing to go in any water pump. See another mechanic, and don't ask him if the water pump is not pumping properly, just ask him to check the cooling system and see what he says.
A water pump can start to 'pump weakly' as the blades on the rotor wear out. That will reduce the amount of coolant that is being moved through the system. That causes the temperature to rise overall. Usually that does not happen before the bearing wears out. When that happens you will normally see some coolant dripping out of the weep hole of the pump if the pump is on the outside of the engine.
