01 XJ 4.0L auto check engine light

[CnoteTJ]

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.

[mallcrawl]

my bet would be the electric fans not spinning, not sure why it would have triggered the check engine light instantly though.

[Axle]

Could be a bad thermostat.

[CnoteTJ]

i was thinking thermostat, i just want to get more opinions if thats not it and the check engine light is throwing me off

[reg]

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.

[HOT-ROD]

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.

[Rebell Bull]

have an OBD11 at shop. The thermostat is probably stuck shut, but I do recommend a heavy duty radiator.

[CnoteTJ]

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

[HOT-ROD]

glad it got figured out.