This noise is going to drive me nuts , nuts , nuts
#1
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Model: Cherokee
This noise is going to drive me nuts , nuts , nuts
Hello fellow Jeepers - I need your help.
The classic 4.0 engine noise is going to put me in a mental hospital if I can't get it resolved
2000 Jeep Grand Cherokee WJ 4.0 in very good shape - I have what sounds like a valve noise but is not constant nor does it remain true to the RPM ( changes intermittent with different rpm and even goes away above 2200 )
What's been done so far :
New lifters installed - new push rods - intake exhaust manifold gasket - head gasket - oil change - flush - cleaned throttle body and AIC valve - checked flex plate - and a few simple things. It really sounds more like a vibration but does increase in frequency with acceleration. I've put a stethoscope under the engine and the majority of the noise can be heard when I make contact with the exhaust pipe just after the split that separates the six cylinders , causing me to think .... Valve train and probably exhaust valve.
I've heard rumors that a CCv and or pcv valve can cause this type of noise. I know the bottom of the engine is in great shape ( wrist pins Pistons main etc ) so I'm good there. Sometimes you hear it well and sometimes it's almost gone. I'm just looking for ANY possibilities from the guys ( or gals ) that have had this type of PITA before and could help me locate the noise before I drive it into the drink. I'm at your mercy my friends - HELP PLEASE
The classic 4.0 engine noise is going to put me in a mental hospital if I can't get it resolved
2000 Jeep Grand Cherokee WJ 4.0 in very good shape - I have what sounds like a valve noise but is not constant nor does it remain true to the RPM ( changes intermittent with different rpm and even goes away above 2200 )
What's been done so far :
New lifters installed - new push rods - intake exhaust manifold gasket - head gasket - oil change - flush - cleaned throttle body and AIC valve - checked flex plate - and a few simple things. It really sounds more like a vibration but does increase in frequency with acceleration. I've put a stethoscope under the engine and the majority of the noise can be heard when I make contact with the exhaust pipe just after the split that separates the six cylinders , causing me to think .... Valve train and probably exhaust valve.
I've heard rumors that a CCv and or pcv valve can cause this type of noise. I know the bottom of the engine is in great shape ( wrist pins Pistons main etc ) so I'm good there. Sometimes you hear it well and sometimes it's almost gone. I'm just looking for ANY possibilities from the guys ( or gals ) that have had this type of PITA before and could help me locate the noise before I drive it into the drink. I'm at your mercy my friends - HELP PLEASE
#3
Old fart with a wrench
Yeah, I'd put my money on the cat. The classic valve noise should disappear above an idle, especially with new lifters.
#4
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Join Date: Sep 2010
Location: Córdoba Ver. México
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Year: 1997
Model: Grand Cherokee
Engine: 4.0L
Hi fellows, i used to have that anoying noise in my XJ, and it was a piston noise, i had to put a set of new pistons in it and the noise went away....that was my experience, hopefully you don´t need to do this, good luck and cheers!!
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