Jeep Liberty overheating after about 20 minutes

[collind]

I tow a Searay 185 with a 2002 Jeep Liberty and its been working fine for the past year until now. Now if I tow for more than about 20 minutes on the highway, my engine starts overheating. The only way to keep in regulated is to turn on the heater (works amazingly well actually). The radiator fan is electric and appears to be working. There are no temperature concerns when I'm not towing, not matter how long a trip.

I've taken the Jeep in to get the the cooling system flushed but mechanics advised that I should need to because its has red coolant rated for 100,000 miles (only have about 70k).

Any advice? I'm thinking about changing the thermostat for the hell of it (even though its not very easy to get to, but it is cheap).

-Collin

 

[CATransplant]

Re: Jeep Liberty overheating after about 20 minutes

Are you absolutely certain the cooling system is full? It can be tough on some vehicles that don't have a cap on the radiator and rely on the expansion tank for filling.

Aside from that, it's the height of summer, and towing is hard. The heater trick is always available, and I've had to do it myself a couple of times.

Are you actually hitting the top of the temp gauge or is it just running hotter than usual?

 

[triumphrick]

Re: Jeep Liberty overheating after about 20 minutes

It seems as tho there are a few people complaining about Libertys and overheating. Check this site...

http://answers.yahoo.com/question/index?qid=20061220165610AAFqt81

Also by you using the heater, you are now exposing coolant to another radiator, the one in the heater. It would appear as in the posted site that you are having a radiator problem...

 

[collind]

Re: Jeep Liberty overheating after about 20 minutes

I don't beleive there is a radiator cap directly on the radiator for this vehicle, I am checking the coolant level by checking the expansion tank. Should I somehow be able to check the radiator directly?

No, I am not allowing it to hit the top of the temp gauge...but if I don't take action it absolutely will. Its not just getting a little hot, it will start to rise quite rapidly once it gets past normal.

 

[zach103]

Re: Jeep Liberty overheating after about 20 minutes

check out jeepforum.com i had a cherokee that i just sold.. but every problem i had big or small those guys knew exactly what could be wrong..not saying that no one knows here cuz everyone here helps alot.. but its specifically for jeeps..

 

[kenmyfam]

Re: Jeep Liberty overheating after about 20 minutes

If rad is in good shape flush and change the coolant. I always drain and run pure water for a couple of days to get the thick stuff out then repeat till the coolant draining out looks reasonable then drain and refill with the correct mix. Dont do it in winter though !!!!
I would also change the thermostat and drop a couple of degrees from standard so it opens a little earlier.
Good Luck.

 

[JB]

Re: Jeep Liberty overheating after about 20 minutes

Please tell us the tow rating of your Jeep as equipped, and the weight of your rig, ready to launch.

I really suspect that you are very near, or over, the limit for your vehicle.

 

[kenmyfam]

Re: Jeep Liberty overheating after about 20 minutes

Please tell us the tow rating of your Jeep as equipped, and the weight of your rig, ready to launch.

I really suspect that you are very near, or over, the limit for your vehicle.

Good Point.

 

[JMRuth72]

Re: Jeep Liberty overheating after about 20 minutes

I would also like to know when on the highway what gear are you in, how fast are you going, and if you have a tach what RPM does it show at speed? Could be that you need to slow down and take it out of OD, transmission is slipping or all of the above. You can roughly calculate how many RPM's you should be turning at 60mph if you know the following information tire size (so you can figure out the circumfrence then how many times it turns in a mile * 60), differential ratio, transmission ratio in the gear being used (in a typical 4spd auto 3rd is 1:1 and 4th is about .75:1). Then you can figure out about what the engine should be turning fairly closely. I say fairly because there is almost always some slip in an auto transmission, but it puts you in a area that is close. The farther away from your projected the more it is slipping and the more heat is being created and the radiator is trying to get rid of especially if you do not have a transmission oil cooler. The more details that you can provide the better. It might take me a little bit, but if you would also supply the tire size I can try and track down what gear ratios you are likely to have (unless you know that already) and I can give you an estimated RPM that you should be running at say 60mph. Let us know everything that you can and we will try to help. Good luck and let us know.

 

[shorts&chanclas]

Re: Jeep Liberty overheating after about 20 minutes

If you tow in the south...flush it at 50k or 5 years no matter what. Agree on the new Tstat. its cheap and make sure that electric fan is working. Thats also a cheap upgrade. All can be done with relative ease...but you may end up killing all the neighborhood cats and turning your driveway into a superfund site doing a flush.

Your rig is @ 3500 lbs which is 1500 lbs below the tow rated liberty. I pulled an 03 Sea Ray 185 with an 03 liberty a few times.

 

[Dunaruna]

Re: Jeep Liberty overheating after about 20 minutes

The radiator is plugged up with carp. Flushing the system will do nothing, the tubes need rodding out. Common problem.

 

[triumphrick]

Re: Jeep Liberty overheating after about 20 minutes

The radiator is plugged up with carp. Flushing the system will do nothing, the tubes need rodding out. Common problem.

Well, I don't know about carp they would have a hard time getting in there.

As I had mentioned earlier. Oldest trick in the book is to use your heater to help cool an engine connected to a plugged radiator. Didn't you say that the heater helped. You realize a heater core is a mini radiator? And by opening the heater valve, you are now directing water through it and that water is being cooled by the heater.

The link you were given stated that a new radiator was purchased to fix the problem.

Once you locate and buy one, use this link for install, Read about the clamps. Good luck.

http://en.allexperts.com/q/Jeep-Repair-817/2008/1/2002-Jeep-Liberty-radiator.htm

 

[fishmen111]

Re: Jeep Liberty overheating after about 20 minutes

Which power package do you have? What are your signs of overheating (gauge only?)? Are you running a tranny cooler and are you towing in OD? If your answers are "no" and "yes", you need to reverse them. People tend to consentrate on just the tranny temp without realizing that the temp is exchanged out in the same radiator that your engine uses for cooling. If you are close to overheating, this can push you over. Also, change your radiator cap. Least expensive, most common cause of overheating. At highway speeds, your cooling fan is useless. Only look that direction if you start to overheat when at a stop.

 

[JT!]

Re: Jeep Liberty overheating after about 20 minutes

based on the fact your radiator probably has 9 times the surface area of your heater core, i'd say your rad is clogged, or damaged. It could be filled with millions of heat-retaining bugs as well. Make sure your rad is not partially obstructed on the outside (air passing through), make sure its full of coolant as well. a bubble stuck in your waterpump, or thermostat can cause a fluid lock, and nothing flows. park on a steep incline and rev LIGHTLY to burp out any bubbles, put your hand on a rad hose, can you feel liquid/heat headed to your radiator, and is the RAD hot?

if you feel the heater core is removing more than a 10% of your total heat, then its doing all the work.

 

[srothfuss]

Re: Jeep Liberty overheating after about 20 minutes

Hey all, fellow Liberty (KJ) owner:

Couple of notes:

1) With the Towing package the KJ is only supposed to tow 5,000 pounds / 500 pound tounge weight with a load distribution system

2) Without the tow pacakage only 3,500 pounds and 350 pounds of tounge weight

3) No mechanical fan means no tow package for 2002 so you are stuck with the lower value... How much does that boat weigh?

4) The Coolant is not DEX cool like GM uses. It is a HOAT coolant that you can only get from MOPAR or Zerex which is labeled as G-05

5) The Plastic endcaps on the radiator tend to spring leaks every now and again... check for leaks!

 

[bruceb58]

Re: Jeep Liberty overheating after about 20 minutes

Also, change your radiator cap. Least expensive, most common cause of overheating. At highway speeds, your cooling fan is useless. Only look that direction if you start to overheat when at a stop.

First off, the purpose of the radiator cap is to raise the boiling point of the coolant. It has nothing to do with the overheat issue unless you are boiling the water out of your radiator.

Second off, the fan is extremely important. First off if the fan is not spinning it is impeding the air going through the radiator and second, at lower speeds(going up hill...stops and starts), you absolutely have to have it to keep a constant high speed airflow over the radiator.

 

[collind]

Re: Jeep Liberty overheating after about 20 minutes

Thanks everyone for all the help.

-No, I don't have the tow package, which I guess means I don't have the tranny cooler. I am judging the overheat condition by the dash temperature gauge, which I assume is the water temp. Correct me if I'm wrong but I didn't think the radiator assisted in transmission cooling.

-Weight of my boat is about 3000 pounds, so yes with gear I am at or slightly exceeding the tow capacity (3500), HOWEVER, I was towing fine last summer without overheating.

-The fact that the heater core worked soo well to bring the temp back to normal made me think that my existing radiator is not functioning correctly.


Again thanks for all the advise! I'm going to change the thermostat this weekend (in case its blocked or not opening all the way) and probablly do a flush and fill and go from there. I'll also check some of the other tips you guys suggested and report back.

-Collin

 

[fishmen111]

Re: Jeep Liberty overheating after about 20 minutes

First off, the purpose of the radiator cap is to raise the boiling point of the coolant. It has nothing to do with the overheat issue unless you are boiling the water out of your radiator.

Second off, the fan is extremely important. First off if the fan is not spinning it is impeding the air going through the radiator and second, at lower speeds(going up hill...stops and starts), you absolutely have to have it to keep a constant high speed airflow over the radiator.

You're exactly right. I meant not to overlook the cap while on the search as they do go bad and are cheap insurance.
Most electric fans free spool so they should not impede airflow. I am sure it could happen, but I have never had one lock up the blades when going bad.

If you were not overheating last summer, as others have suggested, I would look to the radiator/thermostat. Look for bent fins on the front of the radiator. My wife's Liberty grill has very large openings that allow gravel to bend quite a few of them. I go out with a regular dinner knife to straighten them out.

 

[srothfuss]

Re: Jeep Liberty overheating after about 20 minutes

Correct me if I'm wrong but I didn't think the radiator assisted in transmission cooling.

Look at the radiator and you'll see two tiny metal tubes going in on the passenger side of the radiator. These are the tranny cooler lines. All Automatic transmissions have at least the radiator cooler or a small dedicated cooler. You might want to look into an extra cooler considering the weight you are towing

HD package only included:
1) PS Cooler
2) Mechanical Fan + Electrical Fan
3) Tow Hitch + 7 pin harness

-The fact that the heater core worked soo well to bring the temp back to normal made me think that my existing radiator is not functioning correctly.

Since your Liberty is as old as mine (2002) the pressure cap is probably bum. I know that mine was this summer. You'll probably have to swap that out along with the t-stat. And while you are at it, you should swap the radiator hoses too..

Remember about the coolant. Only mopar or G-05 and nothing else. Not even that "works with everything" stuff. The water pump impeller is plastic.

Good luck!

 

[triumphrick]

Re: Jeep Liberty overheating after about 20 minutes

One more thing. If you are going to flush that radiator, there is a proper way to do that. The water flow has to be from the bottom to the top,with the water spilling out thru the radiator cap. You can accomplish this by purchasing a "T" flush kit from the auto store. It usually taps into the heater hose and is left in place, secured by a tight fitting screw cap. Your garden hose connects to it and if you did it right, the water will backflush the rad.