2000 XJ 4.0L 4wd

Recently I've been noticing after driving a pool of coolant under the drivers side (left) of the car. I could see some drips coming off the front bumper but was never able to see the source of the leak. Additionally this was not a consistent leak, some times it would be a large pool other times no pool and I was not noticing a large amount of coolant loss. I also never noticed a smell of coolant or wetness on the passenger floor (looking for a heater core leak) I suspected either a cracked radiator or weep hole leak. Because my apartment does not allow me to work on my car in my lot I took it to my mechanic to have it looked at. When I picked it up they said it held pressure fine. They said they tested it cold and warmed up, and that they ran it hot and could not find any leak. I recently went on a decently far drive before a vacation and when I checked it recently there seemed to be a decent drop in the coolant level, raising my concern again (no overheating, ran at ~210 the entire drive). My question is, if the water pump weep hole is leaking, would that be identifiable with a pressure test? I trust my mechanics but I feel like they may have not ran it long enough for the coolant to spill from the weep hole. Any ideas/education greatly appreciated!

 

I am thinking this probably is not your problem but...
When the weather turned a few years back I developed a small leak coming out under the lower hose on the driver's side.
I figured my 7 or so year old Spectra radiator had bit the dust.
In an effort to not have to replace the radiator I played with the lower hose hoping the leak was coming from there.
No dice.
Then what I thought was a really stupid idea popped into my head.
The fitting for the tranny line on that side has a nut that secures it to the radiator.
Well what if that loosened up and anti-freeze was seeping out from behind it?
Took out the electric fan, put a wrench to the nut, and sure enough was able to snug it up a bit.
All has been fine since.
Until this happened I did not even know that was a thing. LOL.

 

It should NOT leak. Get it tested again. a leaky pump may get its bearing destroyed in short order do to the bearings getting flushed with coolant. then you are stuck and will need a tow.

A leak in the upper hose, or nearby heater hoses can sometime appear to be a pump leak. I have been fooled by that!

Do not ignore it, they never get better. Use of leak stop is not a good option as it can dirty up the whole system.

Find a better apartment.

 

I can't say for certain if you would get a visual result at the weep hole with a pressure test or not. I've never tried it. But look and feel if you have wetness at the weep hole or signs of prior leaking there. If yes... pump has to be changed.
While you're in there... make sure you get a Mopar T-stat, new t-stat housing, and new pump (never reman or rebuilt) brand new ones are reasonable enough in price it isn't worth the risk.
If your hoses are fairly new then I wouldn't replace them, but if you don't know how long they've been on, or show signs of age... don't save 20 bucks on new ones and risk your engine.

Also make sure your pipe going to the heater core is not all corroded inside. if so... replace that too.
I think total you'd be out of pocket maybe 100 bucks tops for everything...and is a pretty easy DIY. I did mine a couple years ago. I think it took me all of an hour or so...and that's because I was going slow and making sure everything was nice and clean before the new parts went on. I've done several vehicles in the past but it was my first time on our old 4.0's. Doing it again, maybe half that time.... it's so much easier if it's a warmer day or you can get it in a garage even temporarily to do it if it's cold out. It'll save your fingers.

Other piece of advise I'd toss your way is when you take the bolts out of the water pump... lay them out in the order/position you took them out. Then put them right back into the old pump for reference as they are different lengths and have to go back in right where they came out.

 

 

Just to clarify, when doing a pressure test for a small leak, you're not looking for it to hold pressure. You're looking to pump it up and then inspect for drips or weeping.