I noticed a small leak coming from the water pump and decided to switch it out. That did take care of my overheating problem, but what caused this

 

Old age.

 

This is just a guess. But, I would say that would cause a slight over heating problem.

 

And play in the shaft.

Think yours looks rough?

 

Damn EZEARL, that thing was essentially useless!

 

Actually I "borrowed" that pic from djb383.

Within the next few weeks I'm going to be replacing the original pump and radiator in mine (everything else already replaced). Be interesting to see what the w/p looks like after 140K miles. No overheating problems in any conditions though.

 

Running straight water will cause that to happen to the fins.

 

Causes corrosion faster?

 

Hell yes.

 

Imagine what the rest of the system looks like.

 

Exactly......

 

I was actually wondering bout that. I replaced the radiator as well and ran the water through the engine till clear water came out. Should I do a different flush?

 

You're probably okay with that.

 

It is ok to use straight water as long as it is distilled water. Tap water has too many impurities and deposits that cause the cooling system to corrode prematurely.

 

Nah. Coolant provides corrosion resistance, lubrication for the pump etc. Do as you choose, but that is not recommended.