mystery coolant

Ok...I usually dont like posting questions like this, but Im getting frustrated. Sorry for the long post too... I have a 94 Sport. 4.0 HO, auto, A/C. I have had a mysterious coolant leak coming from I dont know where. Here is the deal. The other day I smelled and saw steam. So I found the "Flush and Fill" T fitting was leaking. So I replaced that whole heater line with one long piece of hose. Everything was fine until today...5 days later. I get to school...about an hour drive...and I smelled coolant again. Open the hood, no steam, no spewing coolant, but coolant is all over the engine bay. Just drops. It almost looks like I drove through something and it splashed up. Its on the hood a little, its over by the power center, on the wires, on the A/C bracket...everywhere. But its not a lot. Just drops. So I fire the motor up, watch it for a few minutes, rev it...nothing. I can not see where it is coming from. Its not even running out to the ground. WTF?? Anyone have any ideas where coolant likes to sneak out of? Here is what Ive replaced recently. Right after I bought it, around July of this year, I replaced the radiator, all hoses, heater control valve, water outlet, thermostat...everything except for the water pump. I even looked at the pump, but I dont see any wetness at all around it or the pulley or anything. Let me know if you have any ideas. Thanks in advance.

Justin

Kinda just went thru the same deal, I just checked and tightened all the hose clamps and it stopped, still dont know where it was from.

I was going to say it sounds like a "pin hole" in a radiator hose, but you said you recently replaced those. I would go with the other guy and tighten everything up.. just to double check a clamp hasnt come loose. it sounds like something is getting hot, expanding, and leaking...

When you got the new hose, did it have a string threaded through one end and was hanging up on a rack? I know Advance Auto is doing this, and I don't like it. It would be ok if the hole that the string passed through was near the end of the hose, but I've seen a few where the hole was about 1-2" from the end of the hose. Definate leak point.

I´ve had both of my Jeeps do just about what you discribed, both times it was a radiator leak. Both radiators (two different jeeps) in just about the same spot. About half way down the radiator, near the passengers side resivoir, where the water passage, is soldered to the end.
Leak could be anyplace near the fan though, in a hose or what not. If you reused the stock clamps instead of regular hose clamps, this may cause problems. I´d check the top radiator hose connection and/or the heater hose connections.
Sounds like you may be building to much pressure for some reason. Radiator caps, usually get softer. But anything is possible. Does it say what PSI the cap is on the top (think mine is 12-14 PSI). Sure don´t want to have the wrong cap on there, too much pressure can mess up your radiator.

Thanks for all your responses. I think once the rain stops Im going to go around and tighten everything. I know its not a heater hose because I just replaced the heater control valve and I used all new clamps and they are good and dry. But Im not sure about the upper hose clamp. The one on the radiator is kind of hard to get to, so maybe I didnt get a good bite on it.

Its interesting what was said about how the hoses are hung in the store. I work at autozone and thats where I got my hoses. Most of our holders are a paper clip looking thing that just kind of pinches the hose. They dont hurt them at all. But we have newer plastic ones with sharp burrs that hold on to the hose. Some of my newer guys are lazy and they just tug on them. Definetly a possibility. Im going to check it out.

Apparently its an intermittent problem because the same day on the ride home it didnt leak at all. And tonight it didnt leak at all. Its weird. Im pretty sure I have the right cap. I hope its not a pin hole in the radiator. But Im going to get after it tomorrow if its not raining. Check clamps and all that. Thanks again!! Im still open for anymore ideas. Cant have enough of those.

Justin

Check the crossover tube, the small one to the recovery bottle. Could be it rubbed/cut through someplace and is dripping on the top of the radiator shroud. Haven´t seen it on Jeeps, but have seen that tube get pretty hard and crack in places, on other vehicles.
Check for a crust, usually white but sometimes stained the color of the coolant, near the passengers side (outer) of the shroud, inside of the radiator. Hard to see in there, with the shroud on, probably gonna need a flashlight and a mirror.
I pound my Jeep pretty good (hit the stops a lot) on dirt roads. Have seen my radiators kind of bowed in the middle, between the bottom mounts. Think I´m gonna, put a couple of dabs of building foam in there, for a little extra support. Mostly on older radiators though, after some of the heat fins have rotted and the radiator has lost a little integrity.
Noticed many of the newer, replacement radiators (even Modine) have thinner top and bottom sheet metal supports.
Got to make sure there is some clearance between the A/C condensor and the radiator and the condensor mounts are solid, doesn´t take long for the condensor to rub through the radiator if it´s touching.

Hey all. Well today was the last straw. Had to drive about an hour to get to work. Had the heater blowing and I was moving along pretty good. I could see droplets on my windshield and when I wiped they smeared...yup...antifreeze. So I pulled into work, popped the hood. Surprise surpsise, everything is wet with the green stuff. But...no steam, no drips, no nothing. AHHHHH its driving me crazy! It looks dry around the water pump, and the thermostat housing. I can see anything on the radiator itself. But Im guessing it has be coming from right near the fan judging by the pattern. So...here is what Im going to try. Tell me if it sounds sane. Even though its a fairly new radiator, Im gonna buy another today from work. I get my money back from the warrenty anyway. Im also gonna grab a water pump and a few other things since I get 30% off today. I think Im going to just replace the radiator...hopefully it fixes it. Once I get it all apart Ill be able to look around the water pump better to see if maybe that seal is leaking or whatnot. Sound like a plan?

Oh and I did replace that crossover hose for the overflow tank recently. It looks ok. There is a lot of build up of coolant when it leaks right along taht hose. Which is another reason I think its the rad.

I have one question about my cap. Everythign Ive seen/read says 16lbs cap. Is this correct? Ive seen some at 14 too... Let me know. I hope its not due to a stupid problem like that. Thanks again for all the advice.

Justin

Don´t think a couple of PSI is gonna make that much difference. As a general rule, I keep it below one atmosphere, which is around 15 PSI (as a rule of thumb). Eagle is the cooling system Guru, he probably knows the OEM specs.
Problems start when the cap siezes and the pressure gets up above about 25 PSI, you can see the radiator swell, any weak spots are gonna pop.
I´ve popped a couple of heat exchangers, putting a little too much pressure to them, during tests for leaks. I try not to repeat dumb arsed mistakes.
Know one guy, who put a coolant recovery bottle cap (non-venting/fit just fine) on his radiator and it blew up.
On the old XJ´s with the sealed system, the cap siezes from hard water and over pressures the system often. Doesn´t often happen with the open or recovery bottle system. But the wrong cap is always a posssiblity, guy at the parts store just may have given you the wrong one.

My advice is to find the leak. Bummer when you change half the parts, lay out a bunch of cash and the problem isn´t fixed. Wash it, dry it, make sure the radiator is full to the top, start it and watch it close as the temp goes up and it builds pressure. Might stop it every couple of minutes and check for wet spots. Look behind the shroud, if you have to, take the shroud and elec. fan out, so you can see the whole back of the radiator.
I´ve seen little tiny squirts of coolant, spray a couple of feet across the engine compartment. Pin hole leaks.
Another warning, Alernators don´t like coolant, I´ve fried two of the old Delcos after a coolant bath. Think coolant conducts electricity better than water.

Your 16lb cap is fine.
It does look like you have a small leak from the engine side of the radiator, and one of your fans is spraying the coolant all over the engine compartment. I think that if you remove the clutch fan shroud and the electric fan (with shroud), you'll find the leak. If it's very small, you can use a piece of chewing gum to plug the hole.

Hey thanks for the chewing gum idea. I agree with you that it is probably from the radiator. And I definelty know the fan is taking it and distributing it every so nicely around my engine compartment... I bought a new rad tonight, and a new water pump...just so I have them. I had a 30% off weekend at work, so I figured Ide grab them. The rad I have is under warrenty anyway. So if it has a hole I might just swap it. It depends. Its just really weird because I can look under the hood after a semi-long drive, and I know its been leaking, but no matter how long I stare at it, it doesnt do it while Im watching. I cant figure out why it only does it sometimes. Only thing I came up with is that the radiator is an alum./plastic. Maybe one is heating up faster than the other and some expansion problems happen at a certain point...then once they even out in temp it closes back up? Maybe Im just pulling ideas out of my ....

Anyway. Im done school for the semester so I should be able to work on her in the daylight for once. Ill check as best as I can by taking the shrouds off. I gotta get it done because Im ordering my lift kit tomorrow Already have my wheels and tires. So Im all stoked, but I have to fix the coolant leak...and the oil leak first. I gave up on that stupid filter adapter bolt...broke too many tools. Thanks for the advice again.

Justin

Just thought Ide send out an update. Well...I still dont know where exactly it was coming from...but it stopped. I replaced the upper hose, just out of sheer piece of mind. I THINK it may have been a poor seal at the upper radiator outlet. Its kind of hard/tight to get in there with something to tighten up a clamp. Anyway...long story short...I have gone about 2 weeks and a few hundred miles with no leaking...knock on wood. Thanks again for the ideas! Stupid simple problems...

Justin

Resurrecting an old post:

At 85k, I'm doing some upkeep on my cooling system: full flush, radiator cap, fan clutch last week, tomorrow I'm doing the thermostat and maybe the temp sender (always has read a little hot). Anyway, I park it in my garage (it's 11 degrees out) and spray the thermostat with PB Blaster so it soaks overnight. I notice the Mystery Droplets, too. I think it's from the upper radiator hose where it enters the radiator. It seems to have leaked before, but tonight it was pretty wet. I'm assuming that the flush last week might have washed away whatever crud was sealing it, and the system is likely operating at the pressure it was supposed to, and not what the 85k-mile-old cap was holding it at. The freezing cold and extended idle warmups probably don't help.

One more thing to fix tomorrow....