2002 Grand Cherokee Overheating

[Iceman 4401]

My 2002 Grand Cherokee overheats when running and sitting still. I took it to the Jeep service shop and was told that the overheating was caused by the fan not running. In order to fix the problem, they would need to replace the fan, fan module, thermostat at a total cost of $1,100. This doesnt sound right. Can the overheating be totally caused by a bad fan?

[fubijar36]

Yes it can. That's why they put the fan in. When your'e moving there is air flow across the radiator which provides cooling. When you are sitting still the fan causes the same thing. Before changing everything, check each component.It could be as simple as a loose connection.

[Jdeck]

I just replaced my fan/motor assy. It wasn't fun but it did save me money. I have a good fan motor but no fan to mount to it. I couldn't find just the fan so I had to buy the whole assy. That was over $200.

[WSMITH6576]

Originally Posted by Iceman 4401

My 2002 Grand Cherokee overheats when running and sitting still. I took it to the Jeep service shop and was told that the overheating was caused by the fan not running. In order to fix the problem, they would need to replace the fan, fan module, thermostat at a total cost of $1,100. This doesnt sound right. Can the overheating be totally caused by a bad fan?

Did you try replacing the fan relay ?

[JDPascal]

Originally Posted by Iceman 4401

My 2002 Grand Cherokee overheats when running and sitting still. I took it to the Jeep service shop and was told that the overheating was caused by the fan not running. In order to fix the problem, they would need to replace the fan, fan module, thermostat at a total cost of $1,100. This doesnt sound right. Can the overheating be totally caused by a bad fan?

fubijar36 has the right idea. An inoperable fan will cause overheating but a competent and honest technician would be able to locate the defective parts and justify everything he replaces.

These guys might be just covering thier bases and offering a worst case possiblity but it would be unusual for all those parts to need replacing all at once.

The fan relay is easy to check because it is the same as several other relays in the PDC. Simply swap it with another and see what happens.

If you are handy with tools and have a multimeter, you could do some checks your self if you had a manual with the wiring diagrams......

JD

[j.cordero]

most of the cases that happen to me i have change the solid state relay

[seventyghia]

My fan stopped as well, after buying a used fan off of ebay for 60 bucks and not fixing the problem i decieded to buy a temp sensor from o'rileys for 20 bucks, no fix then had a neighbor show me how to by pass certain parts such as the fuse for the fan and the relay, turns out the Relay was fried.

this relay was a pain to get to. it is a four prong relay with two mounting screws. since mine was a 99 it was located under the pasanger headlight, under the black light bucket, behind the bumper cover. since it made me mad trying to take the whole freaking front off just for a relay i used a dremel to cut a square in the light bucket. dont worry i siliconed it back so no leaks....after a week of working on it it was just a relay.....crystler uses the same relay in a lot of its vehicles its number is 04707286AD, the last two can also end in AG or AF. Hope this helps

[blastin512]

my 2002 jeep grand cherokee is overheating at a stand still and the fan is good but jus doesn't kick on to stop it from overheating. could it be the relayis so where's it located

[CAFB 04-12]

Originally Posted by blastin512

my 2002 jeep grand cherokee is overheating at a stand still and the fan is good but jus doesn't kick on to stop it from overheating. could it be the relayis so where's it located

It's behind the passenger side headlamp. I had to loosen the front bumper to get to it.

[blazekka]

Hey guys..

This is more for people who find this in the future. All this came from a person who knows his Jeeps.

I have a 2001 which has suffered the same fate. Jeep has a service bulletin on this topic. Personally I hate electric fans.. just because they seem to fail at a much higher rate than a mechanical clutch type fan.

The 1999 Jeep 4.0 has a mechanical clutch type fan, ANYTHING after that should NOT... From what I understand a common fix is installing a 1999 clutch type gan on the newer 2000 and up models. The fan shrowd is already bowed and is right at home with the clutch fan. The is great to do and safe even if yours did not overheat. Safe insurnace without the tempature spikes of the normal electrical type setups. The 99-2000+ Jeeps already have the threaded water pump which accepts the 1999 clutch style fan anyway.

If your buying a Jeep, look for modded Jeeps that have a hole under the passenger side headlamp. This means that more than likely the truck did not overheat and was serviced before a problem arose.

To my understanding the dealers do not remove the bumpers, too time intensive. So instead they use a 4" hole saw in a specific location and drill a hole to gain relay access. Very quick to do once you know where to drill. I know its kinda hard to ask a dealer to remove the pass headlight when you buying a car, but this could save you some headaches in the future.

So, more than likely if you have a 2000+ jeep with a mechanical fan as well and no access hole, its a good chance your Jeep was overheated and the electrical issue was never resolved. Overheating depending on how severe can lead to transmission problems and a cracked head or head gasket issues later on down the road. Mine became a problem 1 year after overheating. So the overheating of an engine does not necessarily mean immediate problems.

So, if you like your jeep and plan on keeping it, add a clutch type fan as well. Better safe than sorry at little expense. You should be able to find one at you local auto recycler as well.

Hope this helped.. Trust me, I wish I had this info 1 year ago. Good luck.

[Bob D.]

Aside from this thread being over 2 years old... A lot of misinformation in the above post.

The 1999 Jeep 4.0 has a mechanical clutch type fan, ANYTHING after that should NOT...

Actually all the 4.0L motors came with an electric fan as the primary cooling fan starting with the 1999 model year, a secondary mechanical clutch fan was added if equipped with the factory tow or tow prep package.

From what I understand a common fix is installing a 1999 clutch type gan on the newer 2000 and up models.

This is not only untrue it's a very bad idea, it will rob the small 4.0 liter engine of much needed horse power, in fact the opposite is true; people replace the early V8s mechanical fan with an electric to save HP.

Safe insurnace without the tempature spikes of the normal electrical type setups.

My 4.0L with a factory electric fan maintains a constant 210 degrees - the electric fan receives constant input from the PCM and turns off, on, and on high as needed.

So, more than likely if you have a 2000+ jeep with a mechanical fan as well and no access hole, its a good chance your Jeep was overheated and the electrical issue was never resolved.

No access hole means the relay has never failed or if it has it was replaced using the factory instructed method, although there is nothing wrong with drilling an access hole to replace the relay. An engine driven with a improperly functioning cooling fan will be permanently damaged, and most times the damage occurs immediately after driving with an over heated engine.

So, if you like your jeep and plan on keeping it, add a clutch type fan as well.

Do not add a mechanical clutch fan unless it is a secondary, auxiliary fan, gas mileage will suffer using a mechanical fan on a 4.0L as a primary cooling fan.

There is a factory recall (safety issue) of the electric fan on some 2000-2002 JGCs.

[blazekka]

Hi,

Thanks for the information and corrections, this makes even more sense and yes my Jeep does have the tow package.

I realize this thread is old, but I am sure it has been viewed numerious times and could benefit still even more people.

I know the Jeep inline 6 as claimed by many is a very popular solid motor , one of the reasons I had purchased one. I can't see to find any bolt patterns or proper torque specs.

Again, thanks for setting the record straight.