i recently had my ignition coil replaced by a local garage where I used to live. I had my engine light come on again, so I took it to the dealership and they said that the cherokee is very picky with this and only likes to run the stock coil. Among that, they found other little things and a recall, so I told them to take care of the other issues and leave the aftermarket coil in there. Its not even 3 months old and they are telling me to replace it. Should I address this issue later or are they just trying to rape me ?

 

Most of the Jeep aftermarket regular coils I've tried don't last long.
Best place to get a real one is at the dealer - they are not much more expensive there.

If it's a later model coil rail, most are junk Chinese knock-offs. NAPA and CarQuest have the same ones as the dealer but for less.

 

The 4.0 isn't necessarily "picky" about the coil, it's just that most aftermarket coils don't have great reliability or longevity. Accel, MSD, etc. There are many threads of premature fails with them; search to find them.

Stick with a stock OEM style coil. The stock 4.0 absolutely needs nothing more.

 

Wonder what the CEL code number was?

 

Will I just get an engine light if the coil fails or will the truck not start ?

 

My experience has been (not on the XJ), that a coil is either perfect or stone cold dead, no in between. I don't think there is a "coil specific" CEL code.......only code is a cylinder misfire and that can be a number of reasons/causes from no ignition to no fuel. That's why it would be interesting to know what code number(s) the dealer found.

 

I know when my coil went out on my 98XJ I would have problems with it starting then one day it just cut out on me and it wouldn't start. I did have a spark. But it was a very weak spark at best.