Years of 4.0s that require-recommend zinc
#46
when i start it up about 15 seconds in ill hear a slight tap. 3 out of 5 times.. Before it was a SLAP and everytime. But it will come and go Sometimes it's a perfectly sounding engine and then taps randomly then back to perfect sounding.
#47
CF Veteran
An oil filter lacking, or having a defective antidrain back valve can cause lifter noise upon start up as the oil pump must refill the filter, which inturn reduces oil flow to other engine bits, like the lifters. I have had this happen, it was the filter issue. different, i.e. better filter fixed it.
#48
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,971
Received 1,554 Likes
on
1,260 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Could also be a dirty lifter along with a crappy filter.
Have you ever shined a light in the oil filler hole to assess any sludge accumulation?
Have you ever shined a light in the oil filler hole to assess any sludge accumulation?
#49
I believe it's a sticky lifter. And the zinc has made a thin barrier making it less noisy. But I still take it to Redline when I merge onto the free way. If don't beat on it just it the Italian tune up.
#50
::CF Moderator::
Join Date: Aug 2011
Location: Prescott, Az
Posts: 43,971
Received 1,554 Likes
on
1,260 Posts
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
You didn't answer my question though. What oil filter? Have you assessed sludge buildup under the valve cover?
I am totally familiar with the Italian tune-up. LOL. I live by it.
I am totally familiar with the Italian tune-up. LOL. I live by it.
Thread
Thread Starter
Forum
Replies
Last Post
BLUE 01
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
11
08-09-2020 11:55 PM
70hemicuda
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
17
01-29-2018 06:20 PM
OcalaXJ
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
12
04-04-2013 05:28 PM
RICZR2
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
12-27-2010 04:24 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)