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yasoder68 07-07-2010 12:45 PM

03 overland overheating
Anyone have a idea why my 4.7 HO gets hot? While driving temp. stays 210 or below, but sit for for minutes temp goes up 220 plus. One day It did reach the redline and bubbled over. Checked all fluids, everything seems fine. It is 90 to 95 outside, but this is not right. Fan does run slowly at idle.

Unholyskorn86 07-07-2010 02:10 PM

Re: 03 overland overheating
Check to make sure all fans are turning on. Let it idle and watch it heat up and make sure everything cycles on. If it does heat up...check the hoses for more heat then normal or expanding. If none of that shows, i'd replace the thermastat just in case. it is a easy and cheap fix, and is good to do anyway....if none of those work i'm out of ideas bro...

Ooooo....also check the sensor thats under the passanger headlight i think...replace that too maybe.

yasoder68 07-07-2010 02:17 PM

Re: 03 overland overheating
Yes I will put new thermostat in, but not until next week. I gotta work 3 days. Not sure what stock temp the thermostat is, but advance auto has a 195* one for 22 bucks.

Unholyskorn86 07-08-2010 12:36 PM

Re: 03 overland overheating
Yeah bro, 195* is stock, and it's cheap and easy to do. The one thing I suggest is you check it every day to make sure nothing gets clogged in the hoses and makes your engine overheat for too long....

scjeep4.7HO 07-08-2010 01:27 PM

Re: 03 overland overheating
JET has a 180* T stat that i have in right now. It costs a little more then the standard one but well worth it in my opinion, especially on the HO motor.

yasoder68 07-08-2010 03:10 PM

Re: 03 overland overheating
Would you have a part number? Where can I find one at? 03 Grand Cherokee overland 4.7 HO.
The 180* sounds good, will put in as soon as I find one and let you all know how it goes.

Frango100 07-08-2010 04:55 PM

Re: 03 overland overheating
If your jeep has the hydraulic fan feature, the problem could be the hydraulic control solenoid. This fan always runs when the engine is running, however quite low rev. It should run fast when the engine becomes hot.

yasoder68 07-08-2010 07:14 PM

Re: 03 overland overheating
Yes it has the hydraulic fan. Any way to test the relay? I'll see if the fan speeds up when temp. gets high, maybe Friday or Saturday. Will post back...

Frango100 07-09-2010 11:35 AM

Re: 03 overland overheating
It seems that you can only control the fan using a DRB III scan tool. But if its hot outside, it should be enough to warm up the engine and let it idle for some time, to see if the fan speed increases. If not, most probably the solenoid is bad. You could try to clean the connector on the solenoid first.

scjeep4.7HO 07-09-2010 12:30 PM

Re: 03 overland overheating
The JET Stat is part # 10177 for their 180* T-Stat

yasoder68 07-09-2010 03:35 PM

Re: 03 overland overheating
Yes I will verify if the fan speeds up or not and let you know. Thanks for the part # and info, will get back to you all soon.

yasoder68 07-11-2010 07:09 AM

Re: 03 overland overheating
The fan only spins real slow, I let temp go up to 220 ish and fan is just barely turning, this leads me to think fan relay/solenoid. Dont know whether to take to dealer or try fixing myself.

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