Perhaps someone here can give me some suggestions for diagnosing this issue.
When I bought my TJ a few months ago, I found an issue where the engine would whine (for lack of a better descriptor) when hitting 2,000 RPM only while accelerating. This would persist as RPM increased and eventually the Jeep would "push through" it and the noise would stop, or I would shift gears and it would disappear as RPM dropped. I figured it was a belt issue, so I replaced the serpentine belt and the problem seemed to go away.
About a week ago, I noticed the problem has returned, but now it's happening at about 2,800 RPM. Same symptoms otherwise.
Some possibly relevant notes:
When I bought my TJ a few months ago, I found an issue where the engine would whine (for lack of a better descriptor) when hitting 2,000 RPM only while accelerating. This would persist as RPM increased and eventually the Jeep would "push through" it and the noise would stop, or I would shift gears and it would disappear as RPM dropped. I figured it was a belt issue, so I replaced the serpentine belt and the problem seemed to go away.
About a week ago, I noticed the problem has returned, but now it's happening at about 2,800 RPM. Same symptoms otherwise.
Some possibly relevant notes:
- 2003 TJ, 4.0, 5 speed, no A/C
- The issue seems to happen regardless of the outside temperature or the engine temperature
- I can't replicate this while revving the engine in neutral—it seems to happen only when in gear.
- The new belt appears fine. No cracking or obvious issues as far as I can tell.
