Radiator leak below petcock - what's going on in there?

I've got an inconsistent drip coming from the bottom corner of my radiator, and I'm wondering if it could be anything other than a crack/leak in the radiator itself.

00' XJ, 6cyl, 4.0, 4X4

I don't think it's the petcock, and I'm tempted to tighten the bolt on the underside of the radiator (a few inches below the petcock), but I'm hoping someone might be knowledgeable of what's going on where I'm unable to see before I start tinkering any further.

Photos attached are looking straight on with the grill removed, and looking down from between the upper hose and battery.

It's making 50mi drives alright - topping out at around 70mph, and easing into my accelerations, and topping off at about 1/4gal.

Just drove less than a mile and dribbled when I parked, then drove it a little over a mile and it dripped a couple drops, then drove another 2 miles and it was dry... which I found to be odd.

Any thoughts?

p.s. Doesn't appear that I'm able to upload a photo unless it's a link. The bolt I'm thinking about tightening is going upward from the bottom left corner of the radiator, under the petcock. I'd imagine it's just a mounting bold, but there's moister coming from somewhere right around there that I can't see through the radiator coils, and lightly pooling on the strut/body below.

Have you opened the petcock at all? Some have had issues with it leaking afterward.

I had the petcock fail on my 97 with no prompting. It is available separately at most parts stores (as long as its still a factory style radiator.)

Is your thermostat functioning right? Back pressure?
Unlikely, but maybe?

Is the rubber tube from the cap to the overflow bottle split? Seen that a few times.

How old is the radiator? What brand?

I am on my fourth radiator in my 2000 XJ. They keep leaking from the inlet tank. According to a local radiator shop, over time the clamp they use to attach the side tanks to the core loosens with the heating and cooling cycles. Then it starts to leak. My radiator has started leaking again, from the same exact tank as the last 3. I have tried metal tanks (CSF) and had the same result.

I was just getting ready to post on here to see what radiators people are having luck with. I have heard the Summit Racing radiator has been good.

I'm surprised you are having issues in Cali. In Colorado, we have huge temperature swings. A 40 degree swing is not uncommon from one day to the next. My theory is the big temp swings we have in CO is part of the reason why the radiators on these jeeps don't last very long.