Engine Knock -- 00 XJ Motor Into 99 XJ?

Hi all,
I was running errands locally yesterday and my motor started knocking. Sounds a lot like a rod about to give way. The sound is in sync with the engine RPMs, and it makes the noise whether driving or at idle in park. First of all, anyway to diagnose this definitively?

Second, I have the good fortune of having my old 2000 Cherokee (175K) sitting in my driveway. It has been a generous and gracious donor keeping my 1999 XJ alive -- until now. Anyway, I'm wondering if my 2000 long block is a direct swap. I'm halfway there with removing the 00 XJ motor because of all of the peripheral items I've removed. The only issue I seem to recall from my forum research is that the intakes are different. Any advice?

Also, I'll be researching the forums during the rebuild, but any advice in this area is more than appreciated. Thanks!

Yes, I've seriously considered stroking it, but time and money are at issue here. I think I'd like to pull the 99 XJ motor, and take my time stroking that motor as I find the available parts.

jefftrent said:

Hi all,
I was running errands locally yesterday and my motor started knocking. Sounds a lot like a rod about to give way. The sound is in sync with the engine RPMs, and it makes the noise whether driving or at idle in park. First of all, anyway to diagnose this definitively?

Second, I have the good fortune of having my old 2000 Cherokee (175K) sitting in my driveway. It has been a generous and gracious donor keeping my 1999 XJ alive -- until now. Anyway, I'm wondering if my 2000 long block is a direct swap. I'm halfway there with removing the 00 XJ motor because of all of the peripheral items I've removed. The only issue I seem to recall from my forum research is that the intakes are different. Any advice?

Also, I'll be researching the forums during the rebuild, but any advice in this area is more than appreciated. Thanks!

Yes, I've seriously considered stroking it, but time and money are at issue here. I think I'd like to pull the 99 XJ motor, and take my time stroking that motor as I find the available parts.

Click to expand...

Before you start planning to remove the engine; there is another problem that can cause a similar noise....
The bolts that hold the transmissions torque converter loosen up over time.
Remove the transmission inspection cover attached to the bottom of the transmission bell housing and verify the bolts holding the torque converter to the flex plate are tight.
There should be 6 bolts that are torqued to approximately 25 lbs/ft. Couldn't hurt to remove them one at a time and apply blue loctite to the threads....

I removed the transmission inspection cover and checked the torque on the bolts holding the torque converter to the flex plate, and they are fine.

Have you checked the engines oil pressure with a mechanical gauge?
there are several things that can give low oil pressure.
Bearings, oil pump, obstructed suction strainer are just a few.