Pinhole in Water Pump???

so I finally got around to changing the water pump on my wife's 99 4.0 xj sport today, after it ran out of coolant from a leaking radiator today on her way to work.....picked it up, it overheated, and had to have it towed 18 miles homefor 100 dollars.....thank you, Lewisville, TX PD.....long story, and I feel like an idiot for not checking the water first. Anyway, mysterious overheating problem solved. Now, with the new radiator in, I noticed a new leak today. I searched and searched and searched to see where it was coming from until I see a SMALL stream jetting from the water pump behind the pulley. Now ladies and gentlemen, this is not the seal, this looks as though someone drilled a freakin hole in the body of the pump through the casting. WTF? Has anyone ever heard of this before? There's no crack in the pump, but strange enough, there's a pinhole in the body. The other thing is that it only sprays when the engine hsi hot and killed. Won't do it while running.....which is a very good thing for the time being. I just want to know if this has been documented, because it seems WIERD. Thanks for any input. Looks like I'll be changing out a water pump on Saturday. Let's all pray that it makes it to work and back tomorrow. Thanks for any input you guys have.

Rhett in Denton, TX

Most water pumps have a weep hole that allows water to escape when the seal goes bad. I think the idea is that it won't then push under pressure into the bearings, which could cause quick and catastrophic failure. And, of course, it tells you when the seal is bad in a rather graphic way. Anyway, as they say at Microsoft, it's not a bug, it's a feature.

Matt is exactly right. Your new water pump is defective. Hope you got a good warranty. Sorry you have to do the job twice, it has happened to be before.
Good Luck.

I guess that says it all.....gotta go get a new pump...was going to get a new one anyway, but wasn't planning on it so quickly.