NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old May 5th, 2018, 14:34
GreatOdin'sRaven GreatOdin'sRaven is offline
NAXJA Forum User
 
Join Date: Sep 2015
Location: Florida
Posts: 47
Unhappy Another Engine Noise Thread (with audio file)

1999 XJ | 4.0L | 140K Miles

Sorry for another engine knock thread, I've done hours of research, searching forums and this is my last resort.

PROBLEM

SPECIFICS
  • Started after I drove from FL to NV 3 months ago with a U-Haul Trailer
  • No sound when completely cold
  • Sounds starts about about 30 seconds after it warms up
  • Seems to go away when I give it some throttle (or engine is too loud to hear knocking)
  • I'm not sure if it increases with RPM's but it doesn't get any louder with throttle
  • I can only hear it at idle
  • Louder when i'm underneath the Jeep

TROUBLESHOOTING
  • I already removed all 4 flex plate bolts and tightened the hell out of them, sound still exists
  • I put high octane fuel to determine if it was a detonation issue, sound didn't change
  • I removed spark plugs one by one, no change
  • I used a mechanics stethoscope and listened to the top of the valve cover, it all sounds the same to me
  • Compression is steady in all 6 cyl
  • Fuel pressure holds near 50psi after 30 min

OTHER ISSUES
  • I will randomly get a Cyl 1 Misfire
  • Currently have Cyl 1 and 3 Codes
  • Once in awhile, at slower speeds I will press the gas pedal and the jeep will just move at the same speed then all of a sudden lunge forward aggressively (like a late reaction to the gas pedal being pushed)
  • Has lack of power, esp when accelerating.
  • I have a slight vacuum leak that affects my A/C when accelerating

RELATED HISTORY

1.5 years ago the Jeep needed a water plug change. In the process, I changed A LOT of parts all at the same time. The jeep has had engine performance issues ever since. It's just never run the same.... Here's a list of those parts:
  • Head was resurfaced and checked for cracks
  • Head gasket changed
  • Fuel Injectors Swapped (corroded/cracked)
  • Air Intake Replaced (cracked)
  • Exhaust Manifold (cracked)
  • plugs, wires, distributor, cap all replaced (for fun)

I'm about to take this thing apart down to the head gasket again, but would love any insight on what I can do to troubleshoot the issue before I start throwing parts or wasting my time doing unnecessary maintenance. Please help.
Reply With Quote
  #2  
Old May 7th, 2018, 14:53
Lake919 Lake919 is offline
NAXJA Forum User
 
Join Date: Jan 2010
Location: Mobile, AL
Posts: 390
Another Engine Noise Thread (with audio file)

Mine sounded like that and I had a bad lifter and spring.


Sent from my iPhone using Tapatalk
Reply With Quote
  #3  
Old May 12th, 2018, 13:38
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Another Engine Noise Thread (with audio file)

The engine does not sound bad, the sewing machine tick is normal for a 4.0 and the other sounds could be a belt accessory click, nothing more. That is quiet for many 4.0s LOL. The rest I would look for a busted Cat converter honeycomb bouncing around in the Cat. Blocks exhaust, causes miss fires and lacks power, but sometimes the honey comb tumbles, and one second has power and the next blocks exhaust and is a gutless.
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
  #4  
Old May 16th, 2018, 17:31
Henrique - RS Henrique - RS is offline
NAXJA Forum User
 
Join Date: Dec 2017
Location: Brazil
Posts: 4
Re: Another Engine Noise Thread (with audio file)

Mine sounds exactly the same, and after some time I stopped giving a sh*t to it. Sometimes it won't make that sound at all, but as you said, it will only make after some 30 secs or so after a cold start.

BUT... We also have a common issue which bothers me: the late reaction on the gas pedal. It happens to me when I'm on 2nd gear then pull the throttle to the floor. The jeep looks like a turbo after it passes X rpm. Wonder why...
Reply With Quote
  #5  
Old May 18th, 2018, 17:59
alexgalexg's Avatar
alexgalexg alexgalexg is offline
NAXJA Forum User
 
Join Date: Jan 2013
Location: Connecticut
Posts: 373
Another Engine Noise Thread (with audio file)

Try taking off the valve cover and unbolting the rocker arms. Apply assembly lube to each bolt and re torque them down to factory spec. Also remove throttle body and clean it. Good places to start. Mines knocky too it's normal for 4.0 engines. Especially if they have not been well taken care of by previous owners.

I have an xj with 300k on it and not a knock. But my other one has an engine with over 100k less on it and its knocky. Normal and likely unrelated to your issue

Sent from my SM-G950U using Tapatalk
Reply With Quote
  #6  
Old Yesterday, 03:46
Ecomike's Avatar
Ecomike Ecomike is offline
NAXJA# 2091
 
Join Date: Dec 2006
Location: MilkyWay Galaxy
Posts: 15,064
Re: Another Engine Noise Thread (with audio file)

Quote:
  • I will randomly get a Cyl 1 Misfire
  • Currently have Cyl 1 and 3 Codes
  • Once in awhile, at slower speeds I will press the gas pedal and the jeep will just move at the same speed then all of a sudden lunge forward aggressively (like a late reaction to the gas pedal being pushed)
  • Has lack of power, esp when accelerating.
  • I have a slight vacuum leak that affects my A/C when accelerating
Miss fires and related issues can be brand of spark plug, plug wires, HV coil, CPS sensor, vac line leak to the MAP sensor (you have evidence of a vac line leak on the HVAC symptom, and poor acceleration), bad O2 sensor, bad TPS for sure on the poor / late acceleration, and a dirty or bad IAT intake air temp sensor, and wiring or ground issues. Dizzy CAM sensor may be going bad?
__________________
Quote=8Mud: "Go ahead and put up the best fence you can build, I'll bet on some Mexican with a few dollars of nails and a pile of scrap lumber."
34 MPG , '85 2WD Cherokee Pioneer with custom installed, 64 hp, 2.2 L Nissan SD22 Diesel 5 spd Manual; & 4 Renix XJs, '87 Wagoneer 4.0, 4WD, 89-Cherokee, 4WD, '87 Cherokee 2WD, & '89 Cherokee Pioneer 2WD, all 4dr. #2091
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Polk audio noise canceling headphones tcm glx SoCal For Sale 0 December 29th, 2012 09:15
flexplate replaced now weird start noise (with sound file) black_goose OEM Tech Discussion 5 March 10th, 2012 21:15
Name that noise (with video/audio clip. ryan2l OEM Tech Discussion 3 August 7th, 2007 20:36
Can you save a PDF picture file as a JPEG file??? TRNDRVR Non-Tech / Off Topic 9 June 4th, 2005 08:09


All times are GMT -7. The time now is 04:12.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014