'93 4.0L vibration at 3000rpm - JeepForum.com
LinkBack Thread Tools
post #1 of 3 Old 09-14-2009, 07:47 AM Thread Starter
Registered User
1993 ZJ 
Join Date: Dec 2008
Location: NE Illinois
Posts: 14
'93 4.0L vibration at 3000rpm

Lately, my very mature '93 ZJ 4.0L has developed a light-switch sudden engine vibration starting almost exactly at 3000rpm. It was a bit annoying but after I loaned the car to a friend for a couple of weeks it came back with the vibe getting stronger.
It has 177K and is nearly stock; the only work done in memory was a (not too good) trans rebuild about eight or ten thousand miles ago.
My first guess was motor mounts but if there's some other kink to look for, I'd like to hear it.
Any time guesses for a moderately adept home wrench doing a mounts change? That driver-side one looks like a nuisance to get to.

FieldShunt is offline  
Sponsored Links
post #2 of 3 Old 09-14-2009, 09:45 PM
Registered User
1997 ZJ 
Join Date: Dec 2008
Location: Virginia Beach
Posts: 1,625
check both driveshafts for dings, dents and guages. good thinking on the motormounts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
rooster51 is offline  
post #3 of 3 Old 09-15-2009, 05:40 AM Thread Starter
Registered User
1993 ZJ 
Join Date: Dec 2008
Location: NE Illinois
Posts: 14
I actually did have a look underneath and didn't see anything.
Given the exact-to-engine-speed nature of the vibration, which is pretty heavy and of low amplitude, I'm pretty sure on the mounts.
Just hoping there's not a dampener issue to worry about.
Looks like changing the mounts is no simple thing either- that driver's side one in buried under the intake manifold.
FieldShunt 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
Vibration 12xracer ZJ Grand Cherokee Forum 2 06-16-2008 12:05 AM
BAD vibration, TC?? SunWolf ZJ Grand Cherokee Forum 1 06-14-2008 02:01 PM
Vibration greyZJ ZJ Grand Cherokee Forum 6 05-30-2007 12:20 AM
3000rpm Limit??!?! American Racing ZJ Grand Cherokee Forum 13 02-24-2006 11:41 AM
Vibration on protozee ZJ Grand Cherokee Forum 1 08-29-2005 07:36 PM

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