engine noise,knock, goes away
Thread Starter
Banned
Joined: Oct 2016
Posts: 1,553
Likes: 4
Year: 2000 and 1998
Model: Cherokee
Engine: 4.0
i tried to localize it using a hose to listen. it starts as a fairly load knocking sound but goes down in a few minutes. i havent had a "knocker :in a while so i cant figure it. is it lifters/rockers?.
its not ticking like exhaust will do,its metalic.
gets almost silent, and always runs smooth
its not ticking like exhaust will do,its metalic.
gets almost silent, and always runs smooth
Thread Starter
Banned
Joined: Oct 2016
Posts: 1,553
Likes: 4
Year: 2000 and 1998
Model: Cherokee
Engine: 4.0
i cannot localize it but it almost sounds outside the engine, a knock/click, that goes away slowly as it heats up.
the "hose"listening works and i hear no knock in the oil inlet or on in/ex manifolds,valve cover.
the "hose"listening works and i hear no knock in the oil inlet or on in/ex manifolds,valve cover.
Junior Member
Joined: Sep 2014
Posts: 82
Likes: 0
From: Edmonton AB Canada
Year: 1999
Model: Cherokee
Engine: 4.0L
Definitely sounds like piston slap. My old motor had it bad. Simply put the piston has worn down and it moves around in the bore when it's cold, once warm it expands slightly and fits better, and the knocking goes away. If it is this, the knocking should also go away when the engines under load as it stabilizes the piston. Do you have oil consumption? Any oil in the intake filter? These are also signs of this.
CF Veteran


Joined: Mar 2015
Posts: 1,203
Likes: 154
From: Northern CT
Year: 1995
Model: Cherokee
Engine: Turbo 4.0
That is difficult to answer. If it is piston slap and you want to fix it is a rebuild plus machine work. IMO if you did a compression and leak down test with poor results plus had excessive oil consumption then its time for an overhaul. But just piston slap I wouldn't bother.
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Thread Starter
Banned
Joined: Oct 2016
Posts: 1,553
Likes: 4
Year: 2000 and 1998
Model: Cherokee
Engine: 4.0
not something ive had b4 so i dont know what to expect. it feels just normal and quiet when warm, a few minutes now, winter?
how many ? does not sound like all 6!!
how many ? does not sound like all 6!!
Junior Member
Joined: Sep 2014
Posts: 82
Likes: 0
From: Edmonton AB Canada
Year: 1999
Model: Cherokee
Engine: 4.0L
Just drive it until it blows. I drove 80,000k with mine before i pulled it. It had got so bad that it knocked at idle even when it was warm. And even then, I pulled it because i got a new one, not because the old one had blown up yet
Thread Starter
Banned
Joined: Oct 2016
Posts: 1,553
Likes: 4
Year: 2000 and 1998
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Jan 2012
Posts: 2,208
Likes: 5
From: Ocean County, NJ
Year: 1998
Model: Cherokee
Engine: 4.0L
It's a roll of the dice. You may get away with it for a while but if that skirt breaks then I recommend getting a super heavy duty oil pan to help hold all the sheeet in
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Thread Starter
Banned
Joined: Oct 2016
Posts: 1,553
Likes: 4
Year: 2000 and 1998
Model: Cherokee
Engine: 4.0


