knock in bottom end 4.0L?
#1
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knock in bottom end 4.0L?
i have a 97 xj and it has 160k on it and started making a knock coming from the bottom end i checked the rod caps and every thing seems to be tight in their so if its not a rod bearing what can it be?
#2
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where exactly does it sound like its coming from if your sitting in your jeep. if its at an idol try pulling up a bit on your transfer case shifter and seeing if that helps. often enough the linkage gromets get worn out and it makes a nocking noise that sounds a lot like the engine.
-Kyle
-Kyle
#6
when i got my jeep it had a bad knocking noise towards the rear of the engine.
ive had myself and a number of mechanics diagnose it as an engine knock.
so i got a rebuilt engine and had it installed, and while putting it in we found a cracked flywheel. replaced flywheel= no more knocking.
it was a faint hairline crack, difficult to see by removing the dust shield. but its a fairly common occurence on the cherokee's. that faint crack caused the most horrible noise.
ive had myself and a number of mechanics diagnose it as an engine knock.
so i got a rebuilt engine and had it installed, and while putting it in we found a cracked flywheel. replaced flywheel= no more knocking.
it was a faint hairline crack, difficult to see by removing the dust shield. but its a fairly common occurence on the cherokee's. that faint crack caused the most horrible noise.
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#9
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Year: 1991
Model: Cherokee
Engine: 4.0 6
when i got my jeep it had a bad knocking noise towards the rear of the engine.
ive had myself and a number of mechanics diagnose it as an engine knock.
so i got a rebuilt engine and had it installed, and while putting it in we found a cracked flywheel. replaced flywheel= no more knocking.
it was a faint hairline crack, difficult to see by removing the dust shield. but its a fairly common occurence on the cherokee's. that faint crack caused the most horrible noise.
ive had myself and a number of mechanics diagnose it as an engine knock.
so i got a rebuilt engine and had it installed, and while putting it in we found a cracked flywheel. replaced flywheel= no more knocking.
it was a faint hairline crack, difficult to see by removing the dust shield. but its a fairly common occurence on the cherokee's. that faint crack caused the most horrible noise.
#10
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Year: 1998
Model: Cherokee
Engine: 4.0 I6
Does anyone sell a better quality flywheel for the 4.0? My 98 is doing the same thing...also a friend at work with a 94 sounds exactly like mine...
#11
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Year: 90
Model: Cherokee
Engine: 4.0
I had a knocking sound in 4.0l... sounded like something trying to punch a hole in the oil pan at times. Mostly sounded like someone rapping on the oil pan with a hammer. Turned out it was the harmonic balancer was bad.
#12
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Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Had a cracked flexplate on a '92 do that same thing. I pulled the engine to rebuild it and fould the cracks in the flexplate and got another one. Put that same engine back in without so much as an oil change and no more knock.
#13
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Year: 1991
Model: Cherokee
Engine: 4.0 I6
You can check the flexplate bolts and for cracks by taking the lower dust shield off but you have to take the starter off first. If the bolts are lose use some locktite on them. If they are not, then inspect for cracks if none then replace harmonic balancer.
#14
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Year: 1995
Model: Cherokee
Engine: 4.0L
how do you find out if the balancer is bad? it knocks just a little bit, and it sounds like someone is taking a soft faced hammer to the pan.
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