Hey guys, 2000 XJ 4.0 with approximately 150k miles. After a long highway drive yesterday my engine started misfiring badly under load then began with a horrible knock and grinding sound inside which ultimately stalled the engine out. I was able to limp it about a mile home after restarting with some work. It now has a knock which sounds like it is coming from the bottom end of the engine that gets worse upon throttle application. Engine did not overheat and oil pressure stayed/stays steady throughout the entire ordeal with the exception of when it was stalling out obviously. Engine light is flashing but I do not have a reader to pull the code.

Here is a video w/ audio from underneath the Jeep:




Thanks to anyone who can offer some insight

 

It could be torque converter bolt(s) loose, but I can't see where they would cause the engine to misfire and stall out.

More likely something is busted inside the engine block. Bearing, rod, piston, ring, etc.

Might as well replace your 0331 head while you have the engine torn down.

 

wow. I'd pull that pan and take a look at what's going on. you might consider removing the oil filter and cutting it open to see what it caught. have you drained the oil yet?

 

Too late for oil analysis and such.

A connecting rod is getting ready to come thru the side of the block.

Piston skirt gone.

 

Unfortunately for the Jeep and for my wallet, it has been replaced today. Sadly the legendary 4.0 reliability has not held true for me and the vehicle has been a costly money pit since I got it a year ago. Real bummer as I loved this XJ.

 

Well we don't know how the previous owners treated it in its former life.

There are people on this Forum who have 300,000 plus miles on their XJ and don't have to do much to it.

4.0s are tough, but they can only take so much. In addition, a 13 year old used vehicle with 100,000 + miles on it is going to need some things from time to time.

 

Thats how I felt when mine left me stranded in NC (im from ny) nothing happened stopped at a rest stop then started her back up and the piston skirt blew, I ended up driving 50miles, it didnt misfire or toss anycodes just knocked real bad, seems to me its a 00 and up problem where as any other years its almost unheard of, I love my money pit this babys getting a stroker now

 

I agree completely! If anything, the 00+ are the weakest link in the 4.0 line. I believe mine had been leaking a very small amount of coolant through a cracked head which likely slowly wore out the internals. It was a ticking time bomb, really. I bought the jeep with 124k miles and like you said, I can't be sure of the previous owner's maintenance habits.

I am very thankful that it made it almost to my driveway before giving out. I had driven 2 hours just prior from a mountain bike race. Would have really sucked to have had to foot a tow bill only to find out the engine is junked anyway.