Question on water pumps?

I know the 4.9 / 300 six has 2 different water pumps.
One for V belt and the other for serpentine belt.
One spines 1 way and the other the other way.

What would be a sign of using the wrong water pump with the wrong belt system?

The reason I ask is this motor is not from this truck, I don't know what it is from and being it has a van PS pump that is V belt I am guessing it has the right pump ..... but ........

When running with the new radiator and even the old one I have not seen water being pushed out the tubes like I have on other cars & trucks.
Just idling the motor temp does not get up to half in the factory gauge.
There is no sounds of it getting too hot.
I do feel the heater hoses get hot pretty fast compared to the temp gauge & radiator & hoses.

Thanks for any insight you can give.
Dave ----

FuzzFace2 wrote

What would be a sign of using the wrong water pump...

Low coolant flow everywhere at all times, regardless of ambient or engine temperatures.

FuzzFace2 wrote

...it has a van PS pump...

That's a popular swap - all my truck engines have Saginaw pumps.

FuzzFace2 wrote

...I have not seen water being pushed out the tubes...

Do you mean the core tubes in the radiator tank?  That could be from the t'stat NOT being open; or radiator blockage; or reverse-rotation WP.

FuzzFace2 wrote

Just idling the motor temp does not get up to half in the factory gauge. There is no sounds of it getting too hot.

That suggests the pump is spinning correctly.

FuzzFace2 wrote

I do feel the heater hoses get hot pretty fast compared to the temp gauge & radiator & hoses.

That suggests the pump IS pushing good flow.  Have you tried cranking the engine with the t'stat-to-heater hose disconnected from the firewall (heater core)?  It should shoot a solid stream a LONG way.

Why not pull the pump out & check?  It's not hard, and the gasket is cheap.



It's also worth checking for impeller erosion:

Do you mean the core tubes in the radiator tank?  That could be from the t'stat NOT being open; or radiator blockage; or reverse-rotation WP.

 Yes radiator tubes.
Now the t'stat is new and yes I know new could be still bad. But the factory temp gauge is not going to the HOT side, again I know not the best to use.

The old radiator I cleaned and with the water hose had good flow out the tubes and yesterday I installed the new radiator and the reason for this post.

As for the pump I think it is working "some what" because when I first started the truck and felt heater hoses, 1 got hot and the other cold till it went thru the core & intake, I have EFI exh. manifolds so have a water heater plate on the bottom of the intake.

I will keep an eye on this but right now the truck only runs to move in / out of garage.
Thanks
Dave ----