blistovmhz
NAXJA Forum User
- Location
- Vancouver, BC
When RPM's are over 1200, and the clutch is disengaged, I get an intermittent scraping/grinding sound that seems to coincide with engine RPM, and I've got no idea what's causing it.
I originally thought it was my syncros in the transmission, but trans can be in any gear or neutral and when the clutch is disengaged, the trans shouldn't be spinning anything anyhow.
If I let the clutch engage in neutral, the problem immediately goes away.
FYI, the engine also sorta rattles the whole Jeep at idle (runs smooth but feels like something is off balance), and the shakiness goes away over 900RPM.
I also have another intermittent issue that may be related.
Occasionally, especially the day after heavy rain or some wheeling, I'll start the truck but can't get the trans into any gear. When this happens, I just shut off the engine, put the trans in any gear, and start up again. It'll jolt forward a tiny bit but the issue resolves itself immediately and I can usually drive around and start/stop the engine a bunch of times before it happens again.
I figured the second issue had to be the clutch not fully disengaging, but it really does seem to disengage properly as I can't feel any grab.
Any idea on either issue? Are they likely the same issue?
I can't think of any way the clutch would sometimes disengage fully and not other times, nor can I think of any reason the clutch would make a grinding sound at higher RPMS only when disengaged.
*edit*
I should also mention that the engine feels a bit weak (but this may be my imagination). I recently had to get it air cared, failed, did a tune up, replaced plugs/wires/o2 sensors, cleaned everything, put a new HG on, installed a proper exhaust header, and THEN discovered that the CAT had been hollowed out. Passed air care with very good numbers, but poor 4.0L has felt wimpy ever since, and now shakes at idle.
All the mounts are good, and I can't see anything physically loose (though it's possible I've missed something).
I've also done a tonne of other work to the heap in the past few months, which makes it harder to pinpoint what may have caused the shaky idle.
I've also noticed that despite having less power than my other Jeeps, it's producing higher intake vacuum (around 19 for the big shaky jeep, vs. 15-16 for the other ones that run great). Vacuum is a little wiggly, but no more so than the other Jeeps.
I originally thought it was my syncros in the transmission, but trans can be in any gear or neutral and when the clutch is disengaged, the trans shouldn't be spinning anything anyhow.
If I let the clutch engage in neutral, the problem immediately goes away.
FYI, the engine also sorta rattles the whole Jeep at idle (runs smooth but feels like something is off balance), and the shakiness goes away over 900RPM.
I also have another intermittent issue that may be related.
Occasionally, especially the day after heavy rain or some wheeling, I'll start the truck but can't get the trans into any gear. When this happens, I just shut off the engine, put the trans in any gear, and start up again. It'll jolt forward a tiny bit but the issue resolves itself immediately and I can usually drive around and start/stop the engine a bunch of times before it happens again.
I figured the second issue had to be the clutch not fully disengaging, but it really does seem to disengage properly as I can't feel any grab.
Any idea on either issue? Are they likely the same issue?
I can't think of any way the clutch would sometimes disengage fully and not other times, nor can I think of any reason the clutch would make a grinding sound at higher RPMS only when disengaged.
*edit*
I should also mention that the engine feels a bit weak (but this may be my imagination). I recently had to get it air cared, failed, did a tune up, replaced plugs/wires/o2 sensors, cleaned everything, put a new HG on, installed a proper exhaust header, and THEN discovered that the CAT had been hollowed out. Passed air care with very good numbers, but poor 4.0L has felt wimpy ever since, and now shakes at idle.
All the mounts are good, and I can't see anything physically loose (though it's possible I've missed something).
I've also done a tonne of other work to the heap in the past few months, which makes it harder to pinpoint what may have caused the shaky idle.
I've also noticed that despite having less power than my other Jeeps, it's producing higher intake vacuum (around 19 for the big shaky jeep, vs. 15-16 for the other ones that run great). Vacuum is a little wiggly, but no more so than the other Jeeps.
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