94 Cherokee XJ Coolant leak

I've got an intermittent, minor coolant leak on the driver's side of
the 4.0L. She's got about 118K on her. Every so often, I'll find a
tiny puddle (silver dollar size) of coolant under her on this side.

I cannot find any hose that is the culprit. I know there are some
freeze plugs over here, but visually they look ok, near as I can see
(not a lot of room to get in there). I'm using the difference between
"full" and "add" in the coolant bottle over the course of a week.
Before you ask, no white smoke out the back, so I don't think I'm
burning it, and dipstick looks like pure oil.

Aux. fan is running when AC kicks up, so no boil over. Replaced all
hoses, water pump and thermostat about 6 months ago when the water pump
went.

It has me stumped. Any ideas?

Thanks much.

S.

You should see a little corrosion wherever the coolant is leaking from.
Trying taking it for a short drive and getting the engine good and hot - run
the AC, and take it home. Make sure it's hot, and open the hood and look for
a leak try having someone rev the engine while you look, and also try
shutting off the engine and re-checking.

Failing that, you can get a cooling system pressure tester for around $20 at
an auto parts store. Basically, it hooks up where your radiator cap goes and
pressurises the system. It's got a little gauge. If it's got a leak, it'll
leak when you pump it up.


HTH

Carl


> wrote in message
oups.com...
> I've got an intermittent, minor coolant leak on the driver's side of
> the 4.0L. She's got about 118K on her. Every so often, I'll find a
> tiny puddle (silver dollar size) of coolant under her on this side.
>
> I cannot find any hose that is the culprit. I know there are some
> freeze plugs over here, but visually they look ok, near as I can see
> (not a lot of room to get in there). I'm using the difference between
> "full" and "add" in the coolant bottle over the course of a week.
> Before you ask, no white smoke out the back, so I don't think I'm
> burning it, and dipstick looks like pure oil.
>
> Aux. fan is running when AC kicks up, so no boil over. Replaced all
> hoses, water pump and thermostat about 6 months ago when the water pump
> went.
>
> It has me stumped. Any ideas?
>
> Thanks much.
>
> S.
>

It's not the normal condensed water/ice melting off your Air
Conditioner's evaporator, is it, passenger side firewall, while parked?
God Bless America, Bill O|||||||O
http://www.billhughes.com/

wrote:
>
> I've got an intermittent, minor coolant leak on the driver's side of
> the 4.0L. She's got about 118K on her. Every so often, I'll find a
> tiny puddle (silver dollar size) of coolant under her on this side.
>
> I cannot find any hose that is the culprit. I know there are some
> freeze plugs over here, but visually they look ok, near as I can see
> (not a lot of room to get in there). I'm using the difference between
> "full" and "add" in the coolant bottle over the course of a week.
> Before you ask, no white smoke out the back, so I don't think I'm
> burning it, and dipstick looks like pure oil.
>
> Aux. fan is running when AC kicks up, so no boil over. Replaced all
> hoses, water pump and thermostat about 6 months ago when the water pump
> went.
>
> It has me stumped. Any ideas?
>
> Thanks much.
>
> S.

my 96 jeep just went through the same thing and I had a clogged radiator
but yours doesn't sound that bad. Does it only leak when its cold or sat
for a while? It might just be a clamp thats not tightened well and it only
leaks every so often when the car is cool.

I replaced the radiator last summer, so I think I should be ok there.
It really is a puzzler. I've still go the factory spring-style clamps
on the major hoses.

Thanks.

gcdenis wrote:
> my 96 jeep just went through the same thing and I had a clogged radiator
> but yours doesn't sound that bad. Does it only leak when its cold or sat
> for a while? It might just be a clamp thats not tightened well and it only
> leaks every so often when the car is cool.

No, its green.... :-)

S.
L.W.(Bill) Hughes III wrote:
> It's not the normal condensed water/ice melting off your Air
> Conditioner's evaporator, is it, passenger side firewall, while parked?
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> wrote:
> >
> > I've got an intermittent, minor coolant leak on the driver's side of
> > the 4.0L. She's got about 118K on her. Every so often, I'll find a
> > tiny puddle (silver dollar size) of coolant under her on this side.
> >
> > I cannot find any hose that is the culprit. I know there are some
> > freeze plugs over here, but visually they look ok, near as I can see
> > (not a lot of room to get in there). I'm using the difference between
> > "full" and "add" in the coolant bottle over the course of a week.
> > Before you ask, no white smoke out the back, so I don't think I'm
> > burning it, and dipstick looks like pure oil.
> >
> > Aux. fan is running when AC kicks up, so no boil over. Replaced all
> > hoses, water pump and thermostat about 6 months ago when the water pump
> > went.
> >
> > It has me stumped. Any ideas?
> >
> > Thanks much.
> >
> > S.

All good tips, Carl, thank you. I'll give these a try over the
weekend.

S.
Carl wrote:
> You should see a little corrosion wherever the coolant is leaking from.
> Trying taking it for a short drive and getting the engine good and hot - run
> the AC, and take it home. Make sure it's hot, and open the hood and look for
> a leak try having someone rev the engine while you look, and also try
> shutting off the engine and re-checking.
>
> Failing that, you can get a cooling system pressure tester for around $20 at
> an auto parts store. Basically, it hooks up where your radiator cap goes and
> pressurises the system. It's got a little gauge. If it's got a leak, it'll
> leak when you pump it up.
>
>
> HTH
>
> Carl
>
>
> > wrote in message
> oups.com...
> > I've got an intermittent, minor coolant leak on the driver's side of
> > the 4.0L. She's got about 118K on her. Every so often, I'll find a
> > tiny puddle (silver dollar size) of coolant under her on this side.
> >
> > I cannot find any hose that is the culprit. I know there are some
> > freeze plugs over here, but visually they look ok, near as I can see
> > (not a lot of room to get in there). I'm using the difference between
> > "full" and "add" in the coolant bottle over the course of a week.
> > Before you ask, no white smoke out the back, so I don't think I'm
> > burning it, and dipstick looks like pure oil.
> >
> > Aux. fan is running when AC kicks up, so no boil over. Replaced all
> > hoses, water pump and thermostat about 6 months ago when the water pump
> > went.
> >
> > It has me stumped. Any ideas?
> >
> > Thanks much.
> >
> > S.
> >

Not to imply that this is the cause but DC says the factory clamps should
always be replaced because they cannot be retensioned.

Replacement stainless steel screw clamps are generally 2 for 99 cents and
are reusable

Where is your XJ's expansion tank?

Does the radiator to expansion tank tubing run through that area?

Does the exhaust smell sweet?

What prompted the radiator change last summer?

Did you also replace the radiator cap at that time?

Was the thermostat checked or changed?

What coolant was used?

You can visualize the freeze plugs in difficult places by use of a small
mirror, a leaking plug will show rust or coolant traces. You may have a
better view from underneath.


> wrote in message
oups.com...
>I replaced the radiator last summer, so I think I should be ok there.
> It really is a puzzler. I've still go the factory spring-style clamps
> on the major hoses.
>
> Thanks.
>
> gcdenis wrote:
>> my 96 jeep just went through the same thing and I had a clogged radiator
>> but yours doesn't sound that bad. Does it only leak when its cold or sat
>> for a while? It might just be a clamp thats not tightened well and it
>> only
>> leaks every so often when the car is cool.
>

Those are one use only clamps that should be tossed in the garbage when
removed. They lose their spring memory when flexed the second time
usually because or heat and/or the old hose has swelled so they need to
expand more than the original installation calls for.

You should replace them with the screw strap type.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


wrote:
>
> I replaced the radiator last summer, so I think I should be ok there.
> It really is a puzzler. I've still go the factory spring-style clamps
> on the major hoses.
>
> Thanks.
>
> gcdenis wrote:
> > my 96 jeep just went through the same thing and I had a clogged radiator
> > but yours doesn't sound that bad. Does it only leak when its cold or sat
> > for a while? It might just be a clamp thats not tightened well and it only
> > leaks every so often when the car is cool.

I missed some of this thread, but if you can't find the leak, take the
vehicle to a competent shop that has the leak test system that uses
fluorescent dye and UV light. My friend uses this system in his shop, and I
have seen how easy it is to pinpoint even the smallest leaks.

Chris

> wrote in message
oups.com...
>I replaced the radiator last summer, so I think I should be ok there.
> It really is a puzzler. I've still go the factory spring-style clamps
> on the major hoses.
>
> Thanks.
>
> gcdenis wrote:
>> my 96 jeep just went through the same thing and I had a clogged radiator
>> but yours doesn't sound that bad. Does it only leak when its cold or sat
>> for a while? It might just be a clamp thats not tightened well and it
>> only
>> leaks every so often when the car is cool.
>