WHATS THIS NOISE? Timing chain or piston slap? - JeepForum.com
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Cherokee & Comanche Forums > XJ Cherokee Technical Forum > WHATS THIS NOISE? Timing chain or piston slap?

The Original 3/8" Ruffstuff Diff Cover!Ruffstuff Axle Simple Swap Kit!The Ruffstuff NOT Universal 4 Link Kit!

Unread 08-22-2008, 05:50 PM   #1
Registered User
1996 XJ Cherokee 
Join Date: Oct 2006
Location: USA/Japan
Posts: 2,439
WHATS THIS NOISE? Timing chain or piston slap?

At the front of the engine. In the timing chain area.

Used to do it ONLY when COLD, but now it is taking longer and longer for the noise to go away. Today, it didnt go away at all. Sounds like marbles in a can of light oil being rattled around. Been doing it since I bought it and has slowly gotten worse.

Yes, it sounds like a timing chain.

However, another Jeeper said: "No. a '96 timing chain is virtually indestructable. What you are hearing is PISTON SLAP."

Doesnt sound like any piston slap Ive ever heard, and with 217 thousand miles on it, I'd be inclined to think "timing chain." He says piston slap. WTF?

Advice and or input is appreciated before I find myself in a full engine teardown when all I needed was a timing chain. For what its worth, engine runs perfect, oil comes out clean and amber every 3K miles, 40-60 PSI oil pressure, runs at 200 degrees all day long. Good compression and no other engine noises. Runs PERFECT otherwise.


4.0H.O.XJ is offline   Reply With Quote Quick reply to this message
Unread 08-22-2008, 06:24 PM   #2
It's the crank sensor!
tjwalker's Avatar
1999 XJ Cherokee 
Join Date: Nov 2007
Location: Central Minnesota, MN
Posts: 8,706
Have you used a mechanics stethoscope on your engine yet to help isolate it? Engine noises can be tough to track down and if it is piston slap, a stethoscope should be able to isolate it to a certain cylinder.

I believe piston slap usually gets a bit better as the engine heats and metal expands. Doesn't mean that it isn't piston slap that has reached a certain wear point where it stays noisy I suppose.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!
tjwalker is offline   Reply With Quote Quick reply to this message
Unread 08-22-2008, 07:03 PM   #3
Little Red Menace
balloo93's Avatar
1993 XJ Cherokee 
Join Date: Aug 2002
Location: Austin, TX
Posts: 20,821
Check the harmonic balancer and make REAL sure it's not walking back into the timing chain cover.
93 Sport
Beer is proof that God loves us and wants us to be happy............Ben Franklin

Specs in Profile.

balloo93 is offline   Reply With Quote Quick reply to this message
Unread 08-22-2008, 09:48 PM   #4
Registered User
1987 XJ Cherokee 
Join Date: Aug 2006
Location: texas
Posts: 45
my cherokee was doing the same thing and the front two rod bearings were bad. i bought a set of stock bearings and a high volume oil pump since i was loseing pressure.now it runs 30 lbs of pressure after it's hot and doesnt rattle anymore.i did this in the cherokee in a couple of hours.the bearings were like four dollors a piece for each rod and the oil pump was close to seventy.i'm hopein it will hold me until i can come up with enough money to get a rebuild.hope this is of some help.
vinceleonard is offline   Reply With Quote Quick reply to this message
Unread 08-22-2008, 10:05 PM   #5
Registered User
2000 XJ Cherokee 
Join Date: Jun 2007
Location: Bucks County, PA
Posts: 363
Since you're familiar with the knock sound of piston slap and I would agree that doesn't sound like marbles in a can. I might suspect one of the engine accessorys like the water pump, alternator, idler pulley, ect.
Paul_C is offline   Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools

Suggested Threads

Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.