I currently have 5 Cherokees with the 4.0(an 87 first year 4.0, a 96, a 99 that had this noise, a 2000 being rebuilt due to cracked 0331 head, and my beloved SilverStone Metallic 2001. The night I bought my 99(back in September 2007) this noise appeared. I thought it was a bad lifter or cam lobe as well. It turned out to be #2 wrist pin egging out #2 piston. It sounds like this might be happening to your 4.0 in the early stages. If the sound increases with time, like starts to happen at idle, I would consider at least tearing her apart and replacing that piston/wrist pin. I drove mine for over 5,000 miles with that noise, with no damage other than the egged out piston, but there is the chance the piston could break apart.
00 Jeep 4.0 Noisey on hot restart
- Thread starter SwampSurvivor
- Start date
- Status
Originally Posted By: 84zmyfavorite
I currently have 5 Cherokees with the 4.0(an 87 first year 4.0, a 96, a 99 that had this noise, a 2000 being rebuilt due to cracked 0331 head, and my beloved SilverStone Metallic 2001. The night I bought my 99(back in September 2007) this noise appeared. I thought it was a bad lifter or cam lobe as well. It turned out to be #2 wrist pin egging out #2 piston. It sounds like this might be happening to your 4.0 in the early stages. If the sound increases with time, like starts to happen at idle, I would consider at least tearing her apart and replacing that piston/wrist pin. I drove mine for over 5,000 miles with that noise, with no damage other than the egged out piston, but there is the chance the piston could break apart.
Is different than the piston skirt issue? When my 2001 4.0 engine was pulled apart after a failure, the rod and wrist pin were no longer connected to the piston.
I currently have 5 Cherokees with the 4.0(an 87 first year 4.0, a 96, a 99 that had this noise, a 2000 being rebuilt due to cracked 0331 head, and my beloved SilverStone Metallic 2001. The night I bought my 99(back in September 2007) this noise appeared. I thought it was a bad lifter or cam lobe as well. It turned out to be #2 wrist pin egging out #2 piston. It sounds like this might be happening to your 4.0 in the early stages. If the sound increases with time, like starts to happen at idle, I would consider at least tearing her apart and replacing that piston/wrist pin. I drove mine for over 5,000 miles with that noise, with no damage other than the egged out piston, but there is the chance the piston could break apart.
Is different than the piston skirt issue? When my 2001 4.0 engine was pulled apart after a failure, the rod and wrist pin were no longer connected to the piston.
Come to think of it, I think I have heard of a wrist pin issue once before on a 4.0. It's rare, but it can happen on an engine with pressed piston pins like a 4.0.
Originally Posted By: Donald
Is different than the piston skirt issue? When my 2001 4.0 engine was pulled apart after a failure, the rod and wrist pin were no longer connected to the piston.
That almost sounds like yours was a wrist pin issue. Of the pics I have seen of broken piston skirts, most had large pieces of the skirt in the pan, but the piston was still connected to the rod. How long did you say you drove yours for after it started knocking? Maybe it was a broken skirt and the extreme piston slap that resulted broke the piston loose from the rod. Its hard to tell.
Is different than the piston skirt issue? When my 2001 4.0 engine was pulled apart after a failure, the rod and wrist pin were no longer connected to the piston.
That almost sounds like yours was a wrist pin issue. Of the pics I have seen of broken piston skirts, most had large pieces of the skirt in the pan, but the piston was still connected to the rod. How long did you say you drove yours for after it started knocking? Maybe it was a broken skirt and the extreme piston slap that resulted broke the piston loose from the rod. Its hard to tell.
Unfortunately ... my fan is too loud but you can hear it chattering a bit.
http://www.youtube.com/watch?v=CrCJCtlPqwI
http://www.youtube.com/watch?v=CrCJCtlPqwI
- Status
