metalic scraping / grinding noise from engine

Nathanael Rusciolelli

TJ Enthusiast
Original poster
Joined
Dec 4, 2016
Messages
118
Location
North Carolina, United States
For a while I thought this noise was coming from the clutch because it would make it when I shift gears. I now realize however that it is coming from the engine. At a certain rpm (between 2500-3000) is when it happens, so I rev up while driving, then hit the clutch and I hear the noise because it drops through that rpm range. It also makes this noise if I rev it while sitting in neutral, thats how I realized it was coming from the engine. When sitting in the cab, it sounds like its coming from directly underneath me like it was in the bell housing. I've been reading about some people who've had similar noises come from the cat but to me it doesn't sound like it's coming from the rear. The noise is also very inconsistent. I'm looking for some correlation but it's not like it only happens in cold weather or after running for a while. Sometimes it will even make a slight noise while idling. I've yet to hear it while listening under the hood because it is so inconsistent. Any clues would be appreciated.

btw, 2.5l engine if it makes a difference. .
 
Mine make a noise but in my case I know it is the throwout bearing in the clutch. It happens idling after I drive it for a while. If I tap on the clutch pedal sometimes I can get it to stop others I have to push on it about 1/2 " and it stops.


See if you can get an audio recording of it and post it
 
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Can you let the engine idle and have someone rev it while you listen under the hood? I'm asking because it's possible it's a bad pulley bearing. The most typical ones seem to be a bad idler pulley bearing, or a bad alternator pulley bearing.
 
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Can you let the engine idle and have someone rev it while you listen under the hood? I'm asking because it's possible it's a bad pulley bearing. The most typical ones seem to be a bad idler pulley bearing, or a bad alternator pulley bearing.

I have gone under the hood and held the throttle valve open while listening. Can't seem to hear anything when doing that although the frustrating part is the jeep has to be in the right mood to make the noise.
 
Hmmm, so it only happens when you're moving, or does it ever happen when the Jeep is just sitting there idling, not moving at all?
 
Your Camshaft bearing is done.
..... it amplifies when your gear is slowing down because more stress on the camshaft just like when you do an engine brake.
 
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Your Camshaft bearing is done.
..... it amplifies when your gear is slowing down because more stress on the camshaft just like when you do an engine brake.

If this is the case then why does it sound like it's coming from below the jeep when driving? Also, would it make a scraping noise?

I'm really praying this is not the issue. that doesn't sound like an easy fix to me. :(
 
If this is the case then why does it sound like it's coming from below the jeep when driving? Also, would it make a scraping noise?

I'm really praying this is not the issue. that doesn't sound like an easy fix to me. :(

I hope I am totally wrong my friend.
However that's exactly what I suspected when the grinding sound comes from underneath the engine.
Above the engine is like the other symptoms most of the guys already mentioned before my comments.
 
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It's not mine but my nephew's '99 TJ up in Michigan.
He said continuous faint grinding sound is inside the engine down underneath.

But I could be wrong about yours though, and I hope yours is different.
 
Pick up a mechanics stethscope. 90% of the time a noise doesnt go away. You just cant hear it at times. That should help narrow it down.

* edit* beat me to it lol