Water pump question.

[femurphy77]

I was able to locate the coolant crosover tube that Hib confirmed CANNOT be removed. Upon starting the car and adjusting the valves I noticed that the upper left heater hose is hot but the other hose is cool, one of the cooling fans is running as it is hot wired for some reason. I did notice that the air coming through the radiator is cold. I suspect the water pump isn't pumping. Is there a reasonable way to confirm waterpump rotation without removing it? I just don't believe that the pump is pumping, water temp looks good, heater output is nil even when set on high, heater hoses are cold, right radiator hose is cold and cold air coming thru radiator. Any insight would be appreciated. Thanks, FM, Indy

 

[Hib Halverson]

If the water pump was not functioning, the car would overheat shortly after fire-up.

 

[femurphy77]

Let me clarify, there is no 'stat in the car, that was my first thought. I just can't believe there is any flow with the huge temperature differential between the two hoses. I'm not familiar with the flow path of the coolant, my understanding is the cool (er) water is going to enter thru the upper (left) hose and engine heated water exits thru the lower hose. Is this assumption correct? FM, Indy

 

[RonJ]

Any chance you have an air pocket causing problems? Try disconnecting a heater hose at the highest point with the engine running, see if any air burps. Shouldn't be any air at all, just coolant.

You are right, the hot coolant leaves the engine through the upper hose, goes through the rad and goes back to the engine through the lower hose.

As for the water pump not turning, if the pulley is turning, the pump impeller is turning too. 40+ years in the trade, I think I've seen a loose impeller once.

Ron ...

I looked at your post again, it's a bit confusing ... to clarify ... Hot water out the top of the engine, through the upper rad hose, through the radiator to be cooled, cool water out the lower rad hose back into the engine through the water pump.

 

[Ramrod92]

Take a look at this, it's a great read on the LT1 cooling system. http://www.theherd.com/articles/lt1_cool.html

 

[RonJ]

Take a look at this, it's a great read on the LT1 cooling system. http://www.theherd.com/articles/lt1_cool.html

Thanks Ramrod, super article, I sure got educated on the LT1 cooling system!!!!

Ron ...