How can I tell if I have a bad coolant pump.

 

Usually, they will start to leak out the weep hole. Once coolant is low, the engine will over heat. If the blades are deteriorated, you will not get water moving through the coolant system or very little causing the engine to overheat. If the engine is warm enough for the thermostat to be open, you should be able to see the coolant in the radiator moving. However, I have found it hard to see water movement with the LT1. Do not take the radiator cap off if the engine is at normal operating temps.

 

^^ I 2nd that

I lost a head on an engine that had 2 of the 8 blades left on the water pump impeller. Yea not good. I found 5 of the blades right inside the block where the water pump goes.

Massey

 

Ok this is what happened. I noticed coolant leaking. But I didn't see where it was coming from the next day I tried looking for the leak I even started car again. I still didn't see it leaking. I also removed radiator cap and there was no movement. Does the stat have to open first before water starts to circulate?

 

yes the engine has to be to temp for the coolant to move look on the sides of the water pump there should be a 1/4 inch hole that leaks when the pump is no good

and dont open the cap with the engine hot i got some serious 3rd degree burns from a broken cap that blew off when i put my hand near it

 

So then will the engine have to be up to temp for it to leak from the pump?

 

From my past experience, they will leak more when the system is up to normal operating temp and has pressure built up in the radiator and hoses. However, it may be hard to find the leak because it runs down on the engine and burns off or runs back, making it look like the car is leaking somewhere else. Most will not leak unless the pump is spinning. Usually, if they are leaking bad enough, you will find a small puddle of coolant under the car after it has been parked for awhile. It may not be a big puddle, depending on how bad it is leaking.