A Jeep Cherokee Conundrum

[Ausfahrt]

Thanksgiving was planned to be a long weekend getaway to see some family and haul my motorcycle up to get in a little bit of riding in north Georgia. The vehicle of choice was our '96 Jeep Cherokee and I have to admit that I had a few reservations about trusting the 15 year old tractor for a 1000+ mile family trip..

We embarked at 0300 Wednesday morning and about 40 miles into our journey I noticed a lot of fog in the headlights of the car behind us. Then I shifted my eyes to the view ahead and there was no fog at all. That's not fog...its smoke...from my car! I immediately pulled over and opened the hood and smoke rolled out from everywhere. The passenger side of the engine block was wet and when I aimed my flashlight under the car I saw a puddle of oil and a puddle of water.

I unloaded my bike from the trailer for the ride back to get the Civic so I could take the family back home. Later that morning I rode back to a garage that was near the stranded jeep and arranged with them to have it towed to their shop so that they could take a look at it. In my mind I was thinking catastrophic head gasket failure.

Friday afternoon the garage called me and said that they could find nothing wrong with my Cherokee. What the heck? I even confirmed the oil and smoke thing with my wife just to make sure that I hadn't started the holiday libations a little too early. So we paid the towing and diagnostic bill and drove it home without incident. I checked the oil and trans levels and they are fine.

Last night we drove to Home Depot to buy a Christmas tree and we had no problems. I am at a loss as to what to make of this. I started thinking that maybe it was transmission fluid that I saw and not oil.....thoughts?

 

[01rangerxl]

Seems like if it was trans fluid, you'd find it behind the transmission, not in front of it.

I'd clean off the engine compartment thoroghly, check all fluid levels, make sure all caps/dipsticks are secure, then just keep a close eye on it. Check the PCV system as well.

 

[Kira]

Hello, The reservoir bottle for the cooling system is on the passenger side of Cherokees. Our '88 had a 9" square by 8" high plastic bottle closer to the firewall. The '99 has something taller mounted closer to the shock tower. Perhaps someone zealously overfilled the reservoir bottle before you left. Kira

 

[Zaedock]

Originally Posted By: Kira
Hello, The reservoir bottle for the cooling system is on the passenger side of Cherokees. Our '88 had a 9" square by 8" high plastic bottle closer to the firewall. The '99 has something taller mounted closer to the shock tower. Perhaps someone zealously overfilled the reservoir bottle before you left. Kira


Jeep deleted the pressure bottle when they went to the HO in 1991. The bottle from your '88 was not the same type as your '99 (an overflow).


I'd put my money on the oil sending unit. Keep a 1/8" npt plug in the glovebox.

 

[440Magnum]

O-ring under the oil filter adaptor? They're notorious.

As for the water, not a clue there unless it was from the HVAC (were you running the defroster?)

But if its an automatic, I'm wondering if maybe you have a trans problem and it overheats when you drive it harder/farther, which pushes oil out the vent inside the bellhousing, then the spinning torque convertor flings it all around and it weeps out the whole junction between transmission and block.

 

[wsar10]

I would look at oil PSU as well,

Did the oil PSI drop ?
or coolant temp rise ?

I've had MANY jeeps and a few have seemed to leak coolant but never really got low

!

did you check simple things like windshield washer bottle ?
transmission cooler line fitting maybe......

maybe get a 2nd opinion,

 

[MNgopher]

Sounds like a typical issue with the automatic transmission puking fluid when it gets hot. Seems somewhat common on the Cherokees with the AW4 when driven harder - typically towing or pulling long grades in hot weather. If the transmission vent line was blocked somehow, it may have pushed itself out of the dipstick and then all over the passenger side of the motor in the breeze- It doesn't take much to make a James Bond Smokescreen...

As far as the water, I wonder also if the AC/Defroster was on - yet another factor to add to heat loading of the radiator that would also allow transmission temps to rise.

If you plan to tow (at all) with the Cherokee and an AW4, an auxilliary transmission cooler is a very good idea.

And rest easy - the AW4 is a good unit in this application, and since you stopped will likely be no worse for the wear.

 

[Donald]

Put a dye in the most likely fluid.

 

[Ausfahrt]

Originally Posted By: 440Magnum
O-ring under the oil filter adaptor? They're notorious.

As for the water, not a clue there unless it was from the HVAC (were you running the defroster?)

But if its an automatic, I'm wondering if maybe you have a trans problem and it overheats when you drive it harder/farther, which pushes oil out the vent inside the bellhousing, then the spinning torque convertor flings it all around and it weeps out the whole junction between transmission and block.



Thanks for the replies fellas. I was hoping that you would chime in here Magnum, your passion for these old Jeeps jumps out from my screen.

We did have the AC on at the time cruising at 70mph on level ground (Florida aka Flatistan) pulling a 500 lb. trailer with a 500 lb. bike on it for a 1000 lb. total trailer load. This should not have caused the problem IMO.

A second opinion is a great idea and that is on the agenda.

 

[440Magnum]

SHOULDN'T cause the problem, but might if you don't have enough trans cooling or if the trans is getting a little tired. Could also be a sign that the trans is slipping a little- were you towing in 3rd rather than 4th? Doing that helps cool it since it lets the convertor stay locked more.

 

[OtisBlkR1]

I like the bike.

 

[Jim Spahr]

Have you tried a pressure test to find a leak. Shadetree test: Spread newspapers under the Jeep and let it run a few minutes. Then shut it off and let it sit. See if there are any drips on the paper and this will help locate the leak and also tell you what is leaking: ATF, engine oil, coolant, and so on. Good luck.

 

[Ausfahrt]

Lildreama and I had a long discussion over the weekend and our thinking has shifted. Our 16 YO Jeep will be two years older when we move to Vermont and if it is giving us trouble now in sauna central it probably won't do any better in New England.

I drove the Jeep every day this past week and put nearly 300 miles on it without mishap. But I still don't trust it loaded down at hiway speeds for extended distances.

In any case we will not do anything until after the first of the new year. I just want to let things gel a little and not make a hasty decision.

Those new Subaru Foresters sure look nice.

Thanks again for the feedback.