Engine Vibs

[365Jeep]

Lately, I have been having minor, but noticable engine vibrations between 2250-2750 RPMs in my 2001 Sahara. The vibrations are RPM dependant and not associated with any speed or gear. I have checked my fan blades and turned the A/C off, but there is no change. This isn't a stroker related problem, but it's still the AMC straight six. Any suggestions would be greatly appreciated.

David

[SilverXJ]

Check your harmonic balancer. Check your engine mounts. Check your transmission mounts. Check exhaust mounts and for any interference with the frame or body from the exhaust piping. When was the last time you did a tune up?

[365Jeep]

So it's been a while, and I am still having vibration issues. I did a complete frame swap, and I replaced my harmonic damper, motor mounts, and transmission mount. I'm still seeing vibrations between 2250 and 2750 rpms. Any thoughts? I know the clutch was replaced before I bought the Jeep, but the vibration is fairly new.

[SilverXJ]

What about ignition and fuel supply, etc? When was the last time you did a tune up?

[365Jeep]

When was the last time you did a tune up?

Not to sound like a smart ass, but define tune up. I've replaced the plugs, oil, and all the filters. There are no obvious signs of a misfire. Fan clutch maybe? Throw out bearing? I'm at a loss.

[SilverXJ]

Remove the serpentine belt and run it to the vibration RPM to see if it does anything different. Of course, make it quick though. Its noticable in neutral standing still I would assume?

[365Jeep]

Great idea! I tried removing the belt, but the vibration still exists.