coolant leak help?

Driving my 2000 XJ 4.0 home today. Smell coolant, crap that's me.
Coolant is pouring out from near water pump. Add water and drive. Leaks a ton when I shut it off, not as much running. Add more water, by the time i get home, it's not leaking anymore. Added 3 gallons of H20 for 17 miles ride home. What would leak more when not running, and what would go from a "gutter" to not at all?

The water pump has a weep hole i believe... It weeps when the pump is bad. Could be that... But it shouldnt be pouring out, more like a trickle. Or the water pump gasket is bad.

When the engine heats up, when running the metal expands, so it may be sealing the hole during operating temps. Or the movment of the fluid could lessen the leaking. Some things to think about ..

Could it be the heater-core feed tube? Mine was all rusted out and the cause of my coolant leak.

Might be your pump bearings (and/or seal). Mine started making a noise, when I took the belt off to investigate, the water pump pulley flopped around like a bobble head doll. It never did leak any, if much, I didn't notice any stains. My guess is the pump seal has been redesigned, it used to be the seal failed way before the bearings failed to any noticeable degree. Now it seems the bearings can fail and the seal manages to keep most of the coolant on the inside, though it is doubtful to be perfect or reliable. Maybe your bearings are shot and the seal failed for awhile, but is now reseated temporarily.

I gonna replace the heater hoses, t-stat, water pump, had hoses and flush the hole system this weekend. Borrowed a car until then.

pajeepman said:

I gonna replace the heater hoses, t-stat, water pump, had hoses and flush the hole system this weekend. Borrowed a car until then.

Click to expand...

OR you could rent a cooling system pressure tester and find out where that leak is; OR go to a radiator shop and have it checked--likely no/minimal cost; OR stop by a local garage and have them check it for you.

It stopped leaking and the system was under pressure when I got home. Not sure if the tester would show anything. Small amount of play in water pump so I'm gonna replace all the stuff and be good for another 12 years.
The leak was not visible noticable, above lower rad hose, next to block, I was under with a bright light and could not pinpoint the leak location. All the parts and coolant will be under $100 so it's worth the peace of mind as it will be going on a 5 hour trip one way in August.
Still wish I new what happened....oh well.