solomon7
NAXJA Forum User
- Location
- Portland OR
On my 96 auto, 231 etc. I'm getting an odd rattling sound.
It only happens when warmed up and in drive when I feather the pedal above idle to about 14-1500 rpms then it's gone.
It sounds sorta like a fan blade barely hitting something with what could be described as either a faint whistle or squeal, almost like the way a home fan sounds when its bearings are dry. Kind of a slight "grating/grind" but faint. The rattle sound is more prominent with the other noise being its background, if that makes sense.
The sound does not increase with rpms. It is a constant speed until it fades away. I can sometimes get it do do it in Park, but rarely.
My upgraded mech fan is not hitting its shroud, and is nowhere near the radiator (moved rad forward quite a bit and it's mounted solid).
It has at least 3/4 inch clearance from anything near it. Block brackets and mounts are tight and good. The HB is fine and at least a 1/16 inch from the motor.
Trans mount is new and good.
Cat is one year old, and I smacked on it with a rubber mallet a while with no noise (jeep off not running).
I did severely overtighten my belt when I did my water pump a few months ago and loosened it a couple weeks ago to proper spec. I may have damaged my water pump pulley having the belt too tight, but I know what a bad pump bearing sounds like (i've killed 3) and it sounds nothing like what I"m hearing.
Weirdest is that the sound does not increase in speed at all in relation to the rpms or speed. I think it's coming from the front, my brother said it sounds like more in the middle. His ears aren't the best though and I can't make it happen outside the car.
Thoughts?
I assume a loose flexplate or exhaust/intake manifold bolt would make a noise consistent with rpms, so ruled it out. Please correct me if I'm wrong!
It only happens when warmed up and in drive when I feather the pedal above idle to about 14-1500 rpms then it's gone.
It sounds sorta like a fan blade barely hitting something with what could be described as either a faint whistle or squeal, almost like the way a home fan sounds when its bearings are dry. Kind of a slight "grating/grind" but faint. The rattle sound is more prominent with the other noise being its background, if that makes sense.
The sound does not increase with rpms. It is a constant speed until it fades away. I can sometimes get it do do it in Park, but rarely.
My upgraded mech fan is not hitting its shroud, and is nowhere near the radiator (moved rad forward quite a bit and it's mounted solid).
It has at least 3/4 inch clearance from anything near it. Block brackets and mounts are tight and good. The HB is fine and at least a 1/16 inch from the motor.
Trans mount is new and good.
Cat is one year old, and I smacked on it with a rubber mallet a while with no noise (jeep off not running).
I did severely overtighten my belt when I did my water pump a few months ago and loosened it a couple weeks ago to proper spec. I may have damaged my water pump pulley having the belt too tight, but I know what a bad pump bearing sounds like (i've killed 3) and it sounds nothing like what I"m hearing.
Weirdest is that the sound does not increase in speed at all in relation to the rpms or speed. I think it's coming from the front, my brother said it sounds like more in the middle. His ears aren't the best though and I can't make it happen outside the car.
Thoughts?
I assume a loose flexplate or exhaust/intake manifold bolt would make a noise consistent with rpms, so ruled it out. Please correct me if I'm wrong!
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