Very loud Knock/Tick Noise from 2001

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03-08-2012, 05:17 PM

#16

tylerspyler

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Year: 2000.5

Model: Cherokee

Engine: 4.0

Quote:

Originally Posted by cruiser54

No, they cannot. Wanna try something easier if indeed it is the lifters? Drain out a quart of oil and put a quart of Marvel Mystery Oil aka MMO. Been working on both of my Jeeps.

I did that but, with ATF fluid. It cleaned it a little, but did not help the noise.

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03-08-2012, 05:24 PM

#17

cruiser54

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Year: 1990

Model: Cherokee (XJ)

Engine: 4.0

Quote:

Originally Posted by jcampbell99

Mine is doing the EXACT same thing. I am dropping the oil pan this weekend to poke around and see whats up. I have a feeling it is a rod bearing but I am hoping it is a lifter.

Rod bearing knocks do not come and go. They're there and get nothing but worse, rather quickly. Same with main bearings, and as with rod bearings are accentuated by the engine being under a load. Doesn't sound like the case here.

The lifter klack is accompanied by a bit of a miss since a valve is not opening fully when the lifter doesn't pump up.

If your symptoms are teh EXACT same ones as the OP, I wouldn't be pulling the pan at this point.

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03-08-2012, 05:26 PM

#18

cruiser54

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Year: 1990

Model: Cherokee (XJ)

Engine: 4.0

Quote:

Originally Posted by tylerspyler

I did that but, with ATF fluid. It cleaned it a little, but did not help the noise.

Marvel seens to work better than ATF, and nothing's gonna work instantly. Took 1,000 to 1,500 miles for it to clear up on my Jeeps.

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03-08-2012, 08:12 PM

#19

jcampbell99

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Year: 99

Model: Cherokee

Engine: 4.0

Quote:

Originally Posted by cruiser54

Actually, rod bearing knocks can appear to come and go with the thickness of the oil. If the oil is cold and thick, it can provide more of a cushion which prevents the rod from slamming against the crank. I have had a rod knock on a 350 in my Monte Carlo that would only knock when the engine was at operating temp. It ran completely smooth and clean up to that point. My jeep is kinda doing the same thing.

However, I am pulling the pan on mine to eliminate the possibility of a rod bearing and because I need to replace the rear main seal. I am almost positive mine is a stuck lifter.

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04-28-2019, 10:26 PM

#20

VImototv Nick Montes

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Model: Cherokee(SJ)

Quote:

Originally Posted by tylerspyler

That was my first thought but, it goes completely away after I rev it past 1500 rpm or so and, it also will completely go away at idle when it wants to.

I also just did an oil change 200 miles ago with synthetic blend Rottella T5 10w-30 and a mopar filter.

If it helps, it is a LEV, and has 3 cats, 4 o2 sensors, and an evap system that would make a prius driver smile.

Whatmeans LEV?