Dreaded Engine Knock/Tick Question's???
#1
Junior Member
Thread Starter
Join Date: Oct 2013
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Dreaded Engine Knock/Tick Question's???
So Ive been running my 89 xj 4x4 4.0 for about 7-8 months since I bought it and I've noticed that once the engine is warm I get a decently loud lifter tick or engine knock of some sort. I took a stethoscope to the block and head trying to figure out where the noise was coming from exactly without much luck. It sounded like it was coming all from the head.
I know head noise with the 4.0's is a given since it uses a flat tappet cam combo'd with lifters and pushrods but this seems excessive? It does not making any knocking or tapping noises when cold. Only when its fully warmed up. I sort of ruled out a cracked header already because the noise would be right away on start up and deminish when the engine warms up from what Ive seen in person. My 4.0 recently seemed to have gotten louder now that the warm weather is here. Im currently running 5w30 conventional and have yet to try 10w30.
My main question. Is it time for a head rebuild? If soo what do you guys reccomend?
I know head noise with the 4.0's is a given since it uses a flat tappet cam combo'd with lifters and pushrods but this seems excessive? It does not making any knocking or tapping noises when cold. Only when its fully warmed up. I sort of ruled out a cracked header already because the noise would be right away on start up and deminish when the engine warms up from what Ive seen in person. My 4.0 recently seemed to have gotten louder now that the warm weather is here. Im currently running 5w30 conventional and have yet to try 10w30.
My main question. Is it time for a head rebuild? If soo what do you guys reccomend?
Last edited by Takedown; 04-11-2014 at 12:18 PM.
#2
Newbie
Join Date: Feb 2013
Location: maryland
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1996
Model: Cherokee
Engine: 4.0
In some cases it could be the flywheel bolt had backed out and is hitting the torque converter shield. That was my case, had a noise sounding like a lifter tap.
#3
Junior Member
Thread Starter
Join Date: Oct 2013
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
I did some digging threw videos on youtube trying to compare sounds and what I've come up with is it sounds dead nuts identicle to piston slap.
#4
Junior Member
Thread Starter
Join Date: Oct 2013
Posts: 33
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Another thing I have to add is that The knock is very faint when Im driving it regularly. Its only very noticable after I beat on it with some high rpms or high throttle blips and it comes back to idle. The noise cannot be heard at rpms exceeding 1200.
Last edited by Takedown; 04-11-2014 at 01:41 PM.
#6
Junior Member
I have the same noise...I hate it ...only can hear it at idle...not the engine I am sure. Going to pull the auto trans and see if it could be a cracked flex plate or bad balance torque converter.....Trust me... I will find the root cause... John J..
Trending Topics
#11
Junior Member
Found it... cracked / broken flex plate...could not see it from the inspection plate... pulled back the auto trans...removed the plate. I am lucky it did not completely break loose, I am sure it would have sounded like the engine blew..
New Flex Plate, new bolts and new rear motor mount.... Anything else ??
New Flex Plate, new bolts and new rear motor mount.... Anything else ??
#12
Senior Member
Join Date: Mar 2014
Location: Central Indiana
Posts: 552
Likes: 0
Received 0 Likes
on
0 Posts
Year: 1996
Model: Cherokee
Engine: 4.0
Found it... cracked / broken flex plate...could not see it from the inspection plate... pulled back the auto trans...removed the plate. I am lucky it did not completely break loose, I am sure it would have sounded like the engine blew..
New Flex Plate, new bolts and new rear motor mount.... Anything else ??
New Flex Plate, new bolts and new rear motor mount.... Anything else ??
#13
Junior Member
#14
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,875
Received 1,526 Likes
on
1,238 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Here's how to do it.
https://www.cherokeeforum.com/f51/ch...xplate-172081/
Last edited by cruiser54; 09-06-2014 at 08:46 AM.
Thread
Thread Starter
Forum
Replies
Last Post
96Co
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
12
01-10-2024 06:17 AM
riderjay253
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
09-16-2015 11:31 AM
jmarzo
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
09-02-2015 08:29 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)