Rod knock or valve train?

Justemptyeverypocket

Justemptyeverypocket

Possible Maniac
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Joined
Apr 10, 2019
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Silt,Colorado
I have noise in my jeep that i cannot ididentify for the life of me heres a video of it what do yall think? (Apologies for the wind noise) this was taken when the engine was warm after an 18 mile drive from work the second one was on first start up when cold



 
Hard to say, but that sure sounds like rod knock to me.

Have you done a compression test? If not, that's where I would start.
 
Chris said:
Hard to say, but that sure sounds like rod knock to me.

Have you done a compression test? If not, that's where I would start.
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Ill do a compression test this weekend and come back with the results it weird thing about this is the oil pressure is perfect and ive put almost 20k miles on it since it got the jeep
 
Chris said:
It certainly could be valvetrain related as well.
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Its driving me nuts man i had to replace my oil pan due to previous owner taking it to grease monkey and i checked my end play with feeler gauges when i did everything was within spec i did notice that my camshaft was pretty warn but i wouldn't think that could cause a noise that loud
 
Justemptyeverypocket said:
Yeah its an auto flexplate bolts dont really make too much sense to me because i just had the tranny rebuilt and it maoe the noise before that as well
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A rod knock will be heard mostly during very light throttle (just maintaining RPM) and deceleration. In park blip the throttle, if the sound increases as the engine speed drops is almost definitely a rod knock. If the sound follows the speed of the engine check the flexplate, valvetrain and timing chain.
 
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Justemptyeverypocket said:
Its driving me nuts man i had to replace my oil pan due to previous owner taking it to grease monkey and i checked my end play with feeler gauges when i did everything was within spec i did notice that my camshaft was pretty warn but i wouldn't think that could cause a noise that loud
Click to expand...

A worn camshaft could definitely be cause for concern.
 
U8MYDZT said:
A rod knock will be heard mostly during very light throttle (just maintaining RPM) and deceleration. In park blip the throttle, if the sound increases as the engine speed drops is almost definitely a rod knock. If the sound follows the speed of the engine check the flexplate, valvetrain and timing chain.
Click to expand...
so what youre saying in the slower then engine spins the louder rod knocks get?
 
Try this, get a long screw driver, put the handle end to your ear and the other end to the end the engine, YouTube has good videos on this. Work your way around the engine listening for where the noise comes from, like a doctor would with a stethoscope. This will give you a good idea of where to start.
 
Justemptyeverypocket said:
so what youre saying in the slower then engine spins the louder rod knocks get?
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Not exactly, has more to do with load. Imagine if there is a gap between the crank and rod bearing under load the rod is forced to one side taking up the play, but under light load or when free standing decel the rod is no longer held to one side and you hear it knock around.
 
Bill M. said:
Try this, get a long screw driver, put the handle end to your ear and the other end to the end the engine, YouTube has good videos on this. Work your way around the engine listening for where the noise comes from, like a doctor would with a stethoscope. This will give you a good idea of where to start.
Click to expand...
I actually have a mechanics stethoscope when listening its loudest on the camshaft position sensor and bell housing for some reason
 
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