Author Topic: 01 XJ 4.0L auto check engine light  (Read 1975 times)

Offline CnoteTJ

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01 XJ 4.0L auto check engine light
« on: February 28, 2008, 02:02:18 PM »
My buddy started up his XJ this morning and immediately got the check engine light.  After allowing it to warm up for 5 minutes he came back and it was already starting to overheat!  Anyone have any experience with this, also, anyone have a code reader so we dont have to limp-it to advance auto!  Preesh the help homies.
2011 Black Jeep Wrangler Rubicon
4" FT Long Arm w/ CRC link and 35" MTR/K's
Some armor and performance goodies!

www.northridge4x4.com    www.offroadevolution.com   www.full-traction.com

Offline mallcrawl

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Re: 01 XJ 4.0L auto check engine light
« Reply #1 on: February 28, 2008, 02:04:01 PM »
my bet would be the electric fans not spinning, not sure why it would have triggered the check engine light instantly though.

Offline Axle

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Re: 01 XJ 4.0L auto check engine light
« Reply #2 on: February 28, 2008, 02:09:25 PM »
Could be a bad thermostat.
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Offline CnoteTJ

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Re: 01 XJ 4.0L auto check engine light
« Reply #3 on: February 28, 2008, 02:22:16 PM »
i was thinking thermostat, i just want to get more opinions if thats not it and the check engine light is throwing me off
2011 Black Jeep Wrangler Rubicon
4" FT Long Arm w/ CRC link and 35" MTR/K's
Some armor and performance goodies!

www.northridge4x4.com    www.offroadevolution.com   www.full-traction.com

Offline reg

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Re: 01 XJ 4.0L auto check engine light
« Reply #4 on: February 28, 2008, 02:36:12 PM »
not to be too obvious, but to my knowledge XJ's have mechnical fans (at least mine did 2000)  I had similiar problems.  how hot did it get.  fluid level good?  try pulling the thermo and running it.  does it still overheat?  I upgraded to this: CSF heavy duty 3-row for $165.


I loved it, never had problems again.  Mine would overheat anytime there wasn't air moving over the radiator. I tried everything, but finally it came down to the radiator.  EASY INSTALL.

Offline HOT-ROD

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Re: 01 XJ 4.0L auto check engine light
« Reply #5 on: February 28, 2008, 03:30:58 PM »
i would check the oil alos with the cold. if its too thick, not lubricating properly, if there is any. friction =heat.

how deo sthe engine sound when running? and ticking, or stuttering?

other than that i echo what reg posted.

Offline Rebell Bull

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Re: 01 XJ 4.0L auto check engine light
« Reply #6 on: February 29, 2008, 08:59:04 AM »
have an OBD11 at shop. The thermostat is probably stuck shut, but I do recommend a heavy duty radiator.
Lets go see what I can break next

Offline CnoteTJ

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Re: 01 XJ 4.0L auto check engine light
« Reply #7 on: February 29, 2008, 04:43:35 PM »
ended up being the thermostat was toast, so he upgraded to a 180 since it was a 195.  thanks for all the extra ideas guys
2011 Black Jeep Wrangler Rubicon
4" FT Long Arm w/ CRC link and 35" MTR/K's
Some armor and performance goodies!

www.northridge4x4.com    www.offroadevolution.com   www.full-traction.com

Offline HOT-ROD

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Re: 01 XJ 4.0L auto check engine light
« Reply #8 on: March 04, 2008, 11:26:06 PM »
glad it got figured out.