Jeep TJ, Coolant leaking from front oil pan gasket?

Hi Folks,
My 2000 Jeep TJ 6CYL 4.0L has been leaking coolant for some time. Originally, it appeared to leak from the top of the radiator. Given
this, I replaced the radiator. Then it started leaking from where the lower hose connects to the radiator. I then tightened the hose on with hose clamps. Now its still leaking from what appears to be the front passenger side of the oil pan, between the gasket and the bottom of the oil pan below the serpentine belt. I'm pretty sure the leak isn't dripping from above hoses.
The Jeep has almost 150k miles on it. I suspected a bad water pump, however there is no coolant leaking around the water pump gasket. I pulled the oil stick and confirmed the oil is brown, not milky white. When I changed the oil it didn't appear to have coolant mixed in. The cylinders are not misfiring. It's leaking about 1/3 gallon of coolant a drive.
Does anyone have suggestions on the root cause? I was going to replace the water pump and thermostat, but the symptoms don't lead me to believe they are at fault. It seems like an over-pressure problem.
Any insight is appreciated.
Thanks so much, Nick
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Hi Nick, I think you'll find it's leaking from the water pump, from underneath look up following the lower hose up to the pump and at the shaft you will see the stains from coolant leaking from the weep hole:
http://www.autopartsauthority.com/specials/images/cherokee-water-pump-1.jpg
God Bless America, Bill O|||||||O mailto: snipped-for-privacy@aol.com http://www.billhughes.com /

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Thanks Bill. Other people have suggested the water pump. It's possible that the engine is evaporating the coolant drip trail, so I can't see it.
I'm going to replace it, the thermostat and serpentine belt all at the same time.
Nick
On Aug 4, 4:32 pm, "L.W. \(Bill\) Hughes III"

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Thanks Bill. Other people have suggested the water pump. It's possible that the engine is evaporating the coolant drip trail, so I can't see it.
I'm going to replace it, the thermostat and serpentine belt all at the same time.
Nick
Hey Nick, While you're there, go ahead and replace those hoses. It's probabaly time.
Kate 2O|||||||O6 Rubicon
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On Sat, 4 Aug 2007 13:32:53 -0700, "L.W. \(Bill\) Hughes III"
Good one Cooyon, A+ for Bigotry!!!!!!!!!!!!!!!!!!!!!!!!!!

Recipe for a Psychopath:
Emotional & Interpersonal Glib & Superficial Egocentric & Grandiose Lack of Remorse or Guilt Lack of Empathy Deceitful & Manipulative Shallow Emotions Social Deviance Impulsive Poor Behavior Controls Need for Excitement Lack of Responsibility Early Behavior Problems Adult Antisocial Behavior
This is your life,
L.W. "Cooyon Billy" Goatman-Hughes III
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replying to 24Bit� , Mike Daugherty wrote: Encountering the same problem right now. Began over a year ago with a pin-hole leak very bottom left side corner of the radiator at a soldier point. This was manageable, requiring added coolant mix only once every month, and only a little to top of the radiator - temps remained on the low-end as usual.
Then last month in earlier Nov., we had a week-long below freezing in the overnight lows, which expanded the pinhole (coolant was primarily straight water by this time) (my error) to a substantial leak, requiring well over a gallon added each time I drove the vehicle.
So I replaced the radiator, and fixed the problem ... it seemed. I started the engine, and took a very close look under the front end, checking for leaks - there were none. This was Monday.
Vehicle sat for an entire day, not started or driven (Tuesday).
Fired the vehicle up, preparing to leave for my work, and noticed anti-freeze steadily dripping to the ground in a continuous flow. I couldn't see the source at first, so I shut off the engine, and got down to have a look up under the front of the motor.
It appeared that the leak was dispensing right from the front-most portion of the oil-pan lip just in front of the right hand front-most mounting bolt. I removed the bolt - nothing spilled from the hole, so it wasn't coming directly from the oil-pan itself, but wiping things down to clear the grime away, revealed nothing more - I couldn't find any rivulets of anti-freeze running down to the oil-pan from above it, and the hoses/circulation lines were all clamped properly, and dry.
I next examined the water-pump housing, and checked for loose bolts, and possible leakage from there - I found none.
Being that the leaking anti-freeze was clean and had no oil or other contaminates in it, I placed a 2 gal bottle under the leak to trap further liquid for re-use, and am taking a break from further attempts to find a solution, until I can locate someone with more knowledge in this than I possess.
I have read the above responses to the original posted query, and have taken it as far as pricing a replacement water pump, But I need to be absolutely 100% positive that this would be the correct fix to the problem, before I spend the little money I have, on yet another part to "chase" the problem.
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Mike Daugherty wrote:

Mike, if it's only leaking when running (or when hot), suspect the water pump. You'll find a small weep hole just below the shaft - only leaks when there is pressure on the system. Tie a rag around the nose of the water pump so that it isn't hit by the pulley/belt to check for the leak if you can't see it.
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On Sat, 04 Aug 2007 13:32:53 -0700, L.W. (Bill) Hughes III wrote:

Oh, Bill....
I've asked you countless times to stop bragging about that....
Anyway, pulling a train in an alleyway is not exactly something to brag about.
Please stop.
Nobody visits anymore, even the grandkids are beginning to catch on, especially when you wear that horrible snakeskin Speedo with your tutu -- the Speedo is supposed to be worn /under/ the skirt, BTW.
Why didn't I just jump off the Blarney Castle??
Nancy

--
"Jeeps can get up, and jeeps can also go down. Why can't Bill do either?"

-- Nancy Hughes III
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wrote:

You might want to clean everything as best you can, then get a pressure tester and look for leaks. It goes on in place of your radiator cap and has a hand pump to pressurize your system. Places like AutoZone, etc. sometimes loans them out.
Good luck Darrell
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Thanks for the advice. I'll try the tester also.
Nick
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After you stop and it cools for a bit, reach down under the nose of the waterpump just behind the pulley to see if you can feel wet. If so, the pump seal is going.
Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 http://www.imagestation.com/album/pictures.html?id !15147590 (More Off Road album links at bottom of the view page)
Nick Hughes wrote:

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I still don't see any wetness around the water pump. In any case, I'll try changing it and it's seal. I changed the oil today and did notice that it was very BLACK. I think it was changed around 4k ago, but I have never seen it this black. No signs of white or milky oil.
Thanks

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Nick Hughes wrote:

I used to have a big dually chevy with a 454. On a trip to maine it started overheating and when I checked the radiator fluid it was way low. I go hmmm, refill and boogie on down the road only to overheat again, find the fluid low again, and this time radiator fluid all over the engine and underside of the hood. Radiator cap - tight, but loosen and retighten anyway. Hoses - intact. Water pump - not visibly leaking.
I refilled yet again and this time run the motor for a good 20 minutes looking for leaks and none to be found, so head on down the road and tan my hide if it doesn't happen again. I refill everything, run threw all the checks again and stand there watching the motor run and not leak while scratching my head. Finally I reach a foot in the door and start bringing the rpm up while watching under the hood. Nothing at idle, nothing at 1500 rpm, 2000 rpm, 2500, 3000 and bingo, the upper radiator hose starts emitting a nice little stream of fluid from a pinhole.
New hose and I'm a happy camper headed on down the road. Happy that is until some Nanny from Israel loses control of her bosses rice burner and side swipes my nice purdy truck just outside of boston. Other than all that it was a good trip.
The point is your water has to be going somewhere. It is either leaking from the hose, radiator, water pump, or head (does a tj have a water cooled intake?). If it's not escaping there then it's going in the oil (which you say it is not) or it's going up in smoke out the exhaust, which means maybe a bad head gasket or worse, cracked head. A bad head gasket could allow it to directly leak out of the motor as well. Don't just inspect around the water pump/radiator area. Look for water stains down the side of the block.
If you are losing that much water each trip AND it was in the exhaust it should be fairly easy to tell, since your exhaust should be visibly white. Think fog coming out your tail pipe. Likewise easily visible in your oil.
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T. Greening wrote: Nothing at idle,

I have had the same thing happen. I figured it out when my battery on the firewall kept getting wet with coolant.
Mike
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On Sat, 4 Aug 2007, Mike Romain wrote:

For my `89 XJ it was a pinhole in the coolant overflow bottle ghosting away my coolant.
--
"We began to realize, as we plowed on with the destruction of New Jersey,
that the extent of our American lunatic fringe had been underestimated."
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Lee Ayrton proclaimed:

Anyone know what particular plastic the coolant recovery and washer bottle on Jeeps are made of?
I have a crack in the washer bottle [and have a new bottle waiting for the additional round tuit] where it would seem that by using a bit of fiberglass window screen as a support, the old bottle could be recovered with the fiberglass and an appropriate glue--which could include a hot gun melt glue if necessary.
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HI Folks
Just an update. Also, I would like to thank everyone in this group for the help and suggestions. From what it appears, it was the water pump. It must have been leaking out the "weep hole" or the hold that the fan shaft goes into. I replaced it, the thermostat and fan belt. I made sure to clean all the old gasket material off. So far it looks like the antifreeze is holding in the system. I used a pressure tester and it held 18psi for 2 minutes.
The job was fairly straight forward, but even with an air ratchet it took some time.
I figured out how to remove the fan assembly from the fan pulley. In the 2000 TJ 6cyl 4.0L, there are four bolts that hold on the fan pulley. I placed a box wrench on one of the bolts and held it steady. At the same time, I placed a large adjustable wrench on the big single bolt for the fan. This is how I unscrewed the fan assembly. Then after I remove the four bolts holding the fan/water pump pulley on, I used a rubber mallet to knock it free. It was pretty suck on there.
Thanks again, Nick

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Nick Hughes wrote:

Thanks for letting us know how you fixed the problem.
I'm probably going to have to do the same thing on my ZJ fairly soonish. Still have the original pump. :]
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