1. 2001 XJ 204k miles...rod knock, piston slap, something else?

    This started a few days ago. Turned on my Jeep, and the best way to explain the sound is if you've ever run over leaves with a lawnmower, the sound was similar to when the mower sucks the leaves up. It was very brief and didn't linger. When I shifted into drive, I heard a loud tapping noise as I accelerated. The most similar sound I can compare it to is the clicking as you climb the first hill of a roller coaster.

    In the last few days of driving, I've made some observations about the noise. Whether the engine is hot or cold, the noise is equally loud. When I get into higher gears, it fades significantly. When I decelerate, the sound noticeably fades. It never goes away though. I even hear it at idle. I also checked the oil, and it's clean, no metal or discoloration. I've also noticed there has been absolutely no change in oil pressure.

    So far, the only things I've done to see if the noise would quiet at all is adding seafoam to the crankcase, and rying higher octane gas. Neither has done a thing.

    Is this more likely to be rod knock, piston slap, or something else? Is there any way to reduce the noise? It's really annoying.

  2. #2
    Join Date
    Feb 2009
    Dayton Ohio Area

    2001 XJ 204k miles...rod knock, piston slap, something else?

    Mechanic stethoscope to locate noise. It could be all you note and include valves, lifter, rockers oilpump driveā€¦
    To check for a piston skirt crack you need to drop the oil pan.

    Never look down on anyone unless you are helping them up - Jesse Jackson
    "Never look down on anybody unless you're helping him up" - Jesse Jackson

  3. Re: 2001 XJ 204k miles...rod knock, piston slap, something else?

    Also concider a flexplate crack if an automatic. It can sound similar. FYI, premium fuel will not make a difference. Your engine is designed to use regular and premium is a waste of money.

  4. #4

    Re: 2001 XJ 204k miles...rod knock, piston slap, something else?

    Also, this has happened to me on two different cherokees, the bolts holding torque converter to the flywheel had backed out a little and were hitting
    03 rhd tj

Similar Threads

  1. Flex Plate or Piston Slap?
    By CloudmanXJ99 in forum Cherokee, Commander, Wagoneer and Liberty
    Replies: 3
    Last Post: 09-13-2015, 08:06 PM
  2. 4 cyl, piston#3 issue
    By Gennybro in forum Wrangler and CJ
    Replies: 8
    Last Post: 11-25-2011, 12:01 PM
  3. Engine knock, knock, knocking on heaven's door
    By Jambo21 in forum Wrangler and CJ
    Replies: 7
    Last Post: 03-13-2009, 04:05 PM
  4. Blown piston
    By 1989hog in forum Wrangler and CJ
    Replies: 3
    Last Post: 03-11-2007, 01:24 PM
  5. 2003 TJ with "Gear Slap" problem (auto)???
    By ShyD33 in forum Wrangler and CJ
    Replies: 4
    Last Post: 07-20-2003, 08:00 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Log in

Log in