97 ZJ 5.2 cooling leak

Other than "you have a leak." :)

I had a smell of antifreeze one day and never could find it till I stopped outside the bar one evening and decided to open the hood and look.

Dang hose pissed all over me!

Just a pinhole in the return line. I cut an inch off the hose and stuck it back on. Bought a new hose the next day and put it in the jeep. Still running the old hose. :/ but I have a spare. :)

My usual aproach is to dry and clean everything then after the jeep warms up going around with a piece of toilet paper and looking for anything wet.

Worst case is a leak at the pump. Hard to spot till it starts pissing all over the place.

This morning took a look. Radiator full, expansion tank empty. Filled th e expansion tank, started it up and let it come to temperature. No sign of a leak, but no heat and the top hose took a long time to get hot. Shut it off and it sucked the coolant out of the expansion tank down to the "add" mark and seemed to stop. I topped it up and figure I'll give it an hour or so to cool down and for the feeling to return to my fingers and then take another look.

the expansion tank, started it up and let it come to temperature. No sign of a leak, but no heat and the top hose took a long time to get hot. Shut it off and it sucked the coolant out of the expansion tank down to the "add " mark and seemed to stop. I topped it up and figure I'll give it an hour or so to cool down and for the feeling to return to my fingers and then tak e another look.

And it gets weirder. An hour later the expansion tank was empty. I topped it up and ran the engine warm again. No evident leaks. There's glycol dr ipping off the hood that's made a little puddle on the firewall, and a litt le puddle about the same size underneath--but that could have been some I s pilled filling up the expansion tank. With the engine off there's no hiss or other sound suggestive of leakage.

Usually that means the system had air in it, fairly common after refilling to have to top the expansion tank up a few times.

Closed system, the radiator should be full and the expansion tank should just move between low and high.

It's going to have to get up to high temp before there is enough pressure in the system to make a small leak visible. That and sometimes the hoses have to warm up enough for little holes to open up. A good hard squeeze on the top radiator hose can make things show up.

I have had lost coolant due to a leak in the expansion hose right by the radiator cap. Also had a problem with the cap itself leaking (not holding pressure and pushing fluid out into the expansion tank)

A leaky expansion tank will also slowly drain the system. But that usually makes a big mess.

Just to make sure it's not a bigger problem, what color is the oil?

Finding those leaks is a real pain. Didn't find my last one till it up and pissed on me.

Oil's black--needs changing but no water in it (lost a tranny like that bac k in the '60s--drove a Lincoln through a puddle that turned out to be deepe r than I expected and it went right down the dipstick hole).

Took it Midas (don't laugh--the one near here has a really good mechanic if it's not his day off--today, alas, was his day off) and they told me it ne eded a new radiator on the basis of five minutes inspection and on the evid ence of coolant dripping. Since it's dripping from everywhere right now I didn't buy the evidence.

Plan now is to toss in a bottle of Bars Leaks and keep an eye on it and see what happens. If it's going down fast I'll take it to the dealer, who is a bumbling incompetent but at least goes by the book, which is chock full o f diagnostic procedures, if it's going down slow I'll wait until it starts going down fast. And yeah, I know stop leak type products can plug the rad iator. Given that the temperature was zero this morning and supposedly it needs a new radiator anyway, I'll take my chances.

There is a fairly simple way to localize the leak location that works best in cold weather - something all too common around here lately.

Wait until it's dark out. Wipe all the hoses down - just to get any puddles an extraneous dribbles off. With the hood up, dark location, freezing your butt off, fill the radiator. Don't fill the overflow; pull the cap and fill the actual radiator. All this with the engine dead cold.

Get a good flashlight with a bright beam. With the hood up, start the engine and play the flashlight back and forth across the engine bay but not hitting the engine or body. As soon as the engine starts to warm up you should be able to pick up the steam/spray in the beam of the flashlight. That will get to within a few inches of the leak but all you really need to know is which piece of the system is leaking.

This works best in the winter but from the weather charts is look like anyplace North of Key West will probably work this week...

Another option is UV dye, you need that and a black light. Some coolants already glow under black light.

I'm pretty sure the stuff I just put in glows under blacklight. It hurts m y eyes just watching it go in. Anyway, for now things seem to be at least somewhat under control. After I got back from Midas I let it cool down and it stopped at the "full" mark on the expansion tank. I had somewhere I ha d to go so I went, and it's been cooling for an hour since, still at the "f ull" mark.

I'm starting to think I just let a slow leak get ahead of me and it finally decided "enough".

Now if I can find my blacklight--I've got one here somewhere unless I left it at my last job--leaving there was chaotic.

Used to use a big ol 4" one made for haloween till I sorta drove over it.

Picked up one of these for 4$ at a flea market.

These look kinda cool and probably don't eat the batteries so quickly.

Oil's black--needs changing but no water in it (lost a tranny like that back in the '60s--drove a Lincoln through a puddle that turned out to be deeper than I expected and it went right down the dipstick hole).

Took it Midas (don't laugh--the one near here has a really good mechanic if it's not his day off--today, alas, was his day off) and they told me it needed a new radiator on the basis of five minutes inspection and on the evidence of coolant dripping. Since it's dripping from everywhere right now I didn't buy the evidence.

Plan now is to toss in a bottle of Bars Leaks and keep an eye on it and see what happens. If it's going down fast I'll take it to the dealer, who is a bumbling incompetent but at least goes by the book, which is chock full of diagnostic procedures, if it's going down slow I'll wait until it starts going down fast. And yeah, I know stop leak type products can plug the radiator. Given that the temperature was zero this morning and supposedly it needs a new radiator anyway, I'll take my chances.

Is the wet area on the underside of the hood normally above the waterpump?

If so the seals / bearings are going in the waterpump.

Many older 318 (known today as the 5.2) engines would lose the seals just before the pump started making noise.

And the trick on the bypass hose is dish detergent and channel-lock pliers.

Dip the hose ends in a little dish detergent, fold with the pliers till the ends point 90 degrees to each other and then push it on to the t-stat and pump housing nipples.

Use stainless screw type clamps instead of the wire "jesus!!!" clamps (called that because most mechanics take one look at them and say ... jesus!!!!) and you're good to go.

ection is active.

It was on the left (passenger) side of the hood only. Nothing on the right , nothing over front center, nothing on the right valve covers or the air d ucting, but all over the left side, not just on the hood but on the fender and everything. Looked hard at the water pump, it's dry.

Yesterday afternoon it was sitting on the "full" mark with the engine warm. Today, after driving about 20 miles last night and letting it sit overnigh t it's about an inch below "full". No evident new drip marks either.

It was on the left (passenger) side of the hood only. Nothing on the right, nothing over front center, nothing on the right valve covers or the air ducting, but all over the left side, not just on the hood but on the fender and everything. Looked hard at the water pump, it's dry.

Yesterday afternoon it was sitting on the "full" mark with the engine warm. Today, after driving about 20 miles last night and letting it sit overnight it's about an inch below "full". No evident new drip marks either.

If the system still loses coolant, it's one of the heater hoses or the valve controlling the flow to the heater.

Check for coolant or coolant stains on the passenger side of the intake manifold also.

Another possibility, if Mopar hasn't rid the head and block of the front freeze plug is that one of the plugs has developed a pinhole leak or wasn't seated properly.

If that was my 4.0 I'd think heater hoses because that's where they run.

The 5.2 has one heater hose on each side. My first reaction was heater hos e, either a hole or a loose clamp, because the one on the passenger side is in the exact right spot, but I couldn't find anything coming out in any ki nd of volume and there was too much all over everything to spot a drip. On ce things dried off a little I looked and ran my fingers along the undersid e of the hose but didn't see even seepage there.

I've seen hoses that only leak when they get up to temp and pressure. That was what my hose was doing. The cute way of testing is to wrap With a bit of toilet paper then aluminum foil to keep it in place. The tp will catch leaks and the foil keeps it in place for the test.

Also, check the clamp, the self-springy ones get weak over time. Replaced all mine with old fashioned stainless clamps.

With the engine at running temp, wrap a rag around those hoses (they get pretty hot) and move them around a bit. That will often open up a small crack so that you can see it. Same thing for clamps - move the hose so that it flexes at the clamp. What is a small drop or damp spot becomes a fountain under 15 psi or so at temp.

As things stand, after a week it hasn't lost any more coolant, so the Bars Leaks seems to have done the job.

If it lasts until warm weather I'm happy.

om under the hood. I checked at work and there was coolant on the passenge r side of the engine. I stopped off at NAPA on the way home and got a coup le of gallons of premix, filled the reservoir in the parking lot, and it wa s dry when I got home--the temperature redlined about a block from the hous e.

roubleshoot. My first guess is the upper heater hose coming loose from its attachment on the block.

20,000 now. I know he missed the little short bypass hose that you have to pull the water pump to change because it broke around 100,000 and I replac ed both it and the water pump at that time.

can see where it's leaking.

Wednesday afternoon it finally let go in earnest. Problem turned out to be the gasket on the timing chain cover, which apparently had a small crack t hat sealed itself after the first leak, then blew out a chunk on Thursday a fternoon. Too much for me to tackle in the driveway in 5 degree weather--h ad to pay somebody to fix it. 10 bucks for the part, 300 for the labor, an d of course he kept finding other problems.

:(

I had the same feeling with a fuel pump a couple years back. It cut out in a snow/ice storm after getting a full tank of gas. Only place with the part and open was a dealership.

You know what they say... JEEP .. Just Empty Every Pocket. :D