What about friends of the forum, I have an issue with the cooling system of my Liberty for which I find no logical answer and hope you can help me . To do this, I'll try to provide as much information as possible .

Last Saturday we drove from Home to a trail nearby (20 Km/12 mi more or less) , getting there we stopped for breakfast and not even 5 minutes had passed when I noticed steam escaping from the engine compartment . I immediately opened the hood and noticed that the coolant recovery tank was completely full ( this must normally be empty ) and vapor and liquid escaping from the top of it. Moments later the antifreeze in the recovery tank was sucked into the reservoir antifreeze tank ( the left one that normally contains it) .

Although the level of coolant dropped, we circulated a couple of miles on dirt, however decided to stop completely as we heard a bubbling at the top of the radiator. We waited for it to cool ( just over two hours) and drove back home, reaching our destination without any evidence of overheating.

I did not take care to check the coolant level before leaving that day and, since in the course did not show any symptoms , I don't remember to have looked at the meter level temperature of the board, but would ensure that if the needle had passed the middle of the range, I would have noticed .

Researching about what could have happened, did not come to a clear cause and therefore a solution, so I decided to check the correct mix of antifreeze / water and fill to the correct level .

Subsequently I did a test drive in city which reached the level of operation and even with some traffic , which allowed to activate the electric fan to full speed. In this way did not show any problems.

Thinking it might be a problem caused by altitude, I decided to recreate the situation today . Same route , same time , more or less same speed and effectively , reaching the start of the Trail cut the engine and immediately opened the hood , noting that the antifreeze tank was completely full and the recovery compartment began to fill well. Bubbling again sensed in the upper radiator hose and the upper extreme of the radiator.

Turned on again the engine and the coolant level stopped raising, a moment later all coolant went into the tank on the left side but at a higher level than normal ( almost to the top ) . A few moments later turned off the engine and coolant level did not raise again.

I waited about fifteen minutes and made ​​my way back, i had no contingency whatsoever, zero overheating. On this occasion , I can assure you all the way outward and return the temperature gauge needle never exceeded half the range . I have also assured that the coolant level was right before I left and the truck is not leaking because during Sunday and Monday was extensively reviewed and does not throw a single drop anywhere.

Other data that may be helpful:

The radiator was changed in December of 2012 , is practically new .
The system was cleaned the same date and filled with fresh mixture of water and antifreeze , the latter MOPAR brand , right for the Liberty .
The drive belt and the idler pulley have a life of 25,000 Kms (less than 16,000 miles).
The KJ is reaching 95,000 kms now (59,000 miles) .


On the journey that was at fault :

Approx. 21 Km
Variation in altitude from 2526 mt (8290 ft) to 3429 mt (11250 ft).
Variation of temperature from 20 ° C (68ºF) approx . to 11 ° C (52ºF).

The strange part is that during the road trip , there was no traffic and the radiator was receiving good amount of air.

On possible causes:

Thermostat . If not opened, the jeep will overheat soon after starting the march . If not close , take long to warm up , which is not true . Therefore I can not ensure that it is the thermostat.

Radiator cap . It may already be defective (never changed) , but I am surprised that in heavy traffic around the city does not have any symptoms . In addition , no evidence of leakage.

Water Pump. Invites me to dismiss due to the fact that at low speed and heavy traffic, no overheat or symptoms.

Fans . Both work correctly, the electrical seems to work at two speeds , moderate when you turn the AC and higher when a certain temperature is reached. The mechanical fan always turning and no slippage of the drive belt is perceived.

I hope somebody can give me an idea of what is going on in order to know where to attack the problem.

Greetings and thanks in advance

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2006 Limited 4x4 Silver

3.7L gas engine or 2.8L CRD diesel?

1. on a dead cold engine crank it up and idle for say 30 seconds; shut down and radiator cap on coolant tank; if pressure escapes there is a good chance you have a head gasket leak (there are chemical tests for coolant in oil and the reverse).
2. I'm reasonably sure the radiator cap on the coolant tank works just like a conventional radiator cap on a system with a coolant overflow/recovery bottle on the side. So the way the system works is the radiator cap is calibrated for a certain PSI to prevent the escape of coolant into the overflow/recovery side of the system as coolant PSI rises as the engine warms up. If the radiator cap calibration goes bad it will pop off when it shouldn't and send fluid to the overflow/recovery tank to early. If test 1 is negative I suspect you need to replace the radiator cap with a new one calibrated for the proper PSI. Changes in altitude and slightly higher coolant temp (probably not easily seen on the temp gauge) hence higher PSI relative the atmospheric PSI could trip a marginal radiator cap into an overflow as described.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs