4.0 L rattle during idle - JeepForum.com
LinkBack Thread Tools
post #1 of 5 Old 02-16-2003, 03:39 AM Thread Starter
Registered User
Join Date: Feb 2003
Location: Houston, TX
Posts: 2
4.0 L rattle during idle

I have a 94 Cherokee 4.0 4x4 with 155,000 mi. For the past year or so I've been experiencing an occasional rattling noise during idle. The noise is significanlty worse when the compressor is on (I'm guessing it is the additional load). Also, there is often an associated shudder/CLANK when starting or shutting off.

This noise is best described as "sounding like there is a bolt (or marbles) sloshing around in the crankcase". It is a low pitched chunk/clank, shuddering, metal-on-metal sound which appears to be coming from the very rear of the engine or torque converter.

My Torque converter suspicions were strengthened when I removed the flywheel covers and realized that the 6 bolts on the flywheel were scraping a nice circle on the backside of the covers. The holes in the flywheel thru which these bolts mounted were "stretched" i.e. not round, but eliptical in the direction of rotation. This observation explained a different, pinging noise that recently prompted me to get under the hood. Obviously, i'm getting a new flywheel, but I think the idle problem may be something else.

Has anyone experienced this before? A mechanic said he was certain that it was coming from bad pushrods, so I'm guessing it is probably in the converter or transmission. I pulled the rods, they looked fine.

I'm pretty comfortable under the hood, as are most of my friends, who are all a bit stumped. Thanks in advance for any help.

andymigs is offline  
Sponsored Links
post #2 of 5 Old 02-17-2003, 12:17 AM
Jerry Bransford
Jerry Bransford's Avatar
2004 TJ Wrangler 
Join Date: Jan 2003
Location: Escondido, California
Posts: 69,203
When catalytic converters break up inside, as they do, they have a mean rattle that is often especially bad when the engine is at idle.

When you have a choice, buy American made.
Jerry Bransford is offline  
post #3 of 5 Old 02-18-2003, 10:04 PM
Registered User
Join Date: Dec 2002
Location: San Diego, Ca.
Posts: 47
If the rattle kind of reminds you of a diesel engine at idle, then it is semi-normal for the 4.0 during the 92-94 year range, mine rattles at idle, but runs great, if you bump up the octane, it helps, but with the gas prices, put up with the rattle. If the noise sounds like marbles, then good luck and keep hunting..
wildvan is offline  
post #4 of 5 Old 02-19-2003, 04:34 AM Thread Starter
Registered User
Join Date: Feb 2003
Location: Houston, TX
Posts: 2
Marbles, that's it

Thanks Wildvan,
I think we have the same problem. I've been ignoring it for a long time, and it has become intolerable. Hopefully yours won't get to this stage anytime soon. There is a fine line between the "diesel option" (as we call it) and something which draws strange glances from other motorists and "what is wrong with your engine" comments. Mine has crossed that line.
andymigs is offline  
post #5 of 5 Old 02-19-2003, 08:26 AM
Registered User
Join Date: Dec 2002
Location: San Diego, Ca.
Posts: 47
If it has gotten that bad, then here is something you will not like, I talked to the jeep dealers and also called Chrysler, they all said it was normal. and the only way to get rid of that problem was to replace the head. They quoted as saying it was due to the valve train. If they are correct in what they are saying, then you may need to A) try overhauling the head you have or B) Buy a new head. Before this, try to increase your octane and see what happens..
Hope it works out, remember, there are some nice big valve heads out there
wildvan is offline  

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.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Rattle at idle with 4 cyl. XJ gobabcock Engines & Drivetrain 0 03-10-2009 06:01 PM
Which rattle can? vfrpilot General Jeep & Off-Road Equipment 3 04-14-2007 10:52 AM
OD - Rattle Can or Gun mountaineerjp General Jeep & Off-Road Equipment 2 01-31-2007 09:23 PM
The rattle has got to go. Pantophobia Audio, CB & Ham Radios, GPS, & Electrical 4 10-11-2006 04:04 PM
Exhaust Rattle Jakemd98 Engines & Drivetrain 4 06-08-2006 06:33 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome