odd engine vibration

[speedymax]

My 06 @ 10800 miles TB suddenly has this weird vibration that can be felt through the entire Suv. This is how i will best try describe it :
when turning the egnition you can feel on the brake and axcelerater a feeling of iron grinding. once motor runs and you slowly rev up you still can clearly hear and feel a growling noise. at 1300 rpm it sounds if it might be missing but yet it does NOT.feels like a unbalanced motor. in gear under load no matter what speed it feels like something is shaving. i know its NOT the transmition,but the noise is sure louder under load. same noise in park or neutral. Some times it wil just quit, but for that i have to restart. it would not last more then 5 min and it will be back.NO lights has come on. No power loss. but from scale one to ten ten worse i would say this noise is at 7 - 8 on feeling it vibrating under your feet. feels like something shaving... if any one has a same kinda issue please help before i have this go in and spend hundreds of $$$. Thankyou all

[maxwedge]

Loook for the exhaust or a shield grounding against the body.

[speedymax]

Thank you for the tip. I Did spend time looking for any shields or covers to be lose or touching or any thing like that. so far no luck. what i did find was since i cranked it up this afternoon it has not once done it again. drove 9o miles and as good as it could be.Then i stoped at the shop ,got back , cranked it up and there it was again. it gets worse every time now it seams. i am having the codes red tomorrow... i will post what ever is wrong with it !!

[jdmccright]

Does the vibration/noise go away when you turn the A/C on or off? My inkling is a failing A/C compressor or A/C clutch.

For the compressor to be going bad, the noise and vibration would occur when the A/C is ON and compressor is turning. It will cycle on and off to keep a nominal pressure in the system. When it cycles on is when the noise/vibe would happen...usually a loud clattering noise. This can be caused by a failing shaft bearing or the internals.

The cycling is controlled by the A/C clutch mounted in between the pulley and the compressor. This can fail in a few ways that can give you the nasty vibe/noise. One, the clutch bearing that is used to allow the belt to spin while the compressor is at rest can fail, creating a scraping/rattling sound when the A/C is OFF.

Second, when the A/C is ON, the clutch plate itself can become worn or the electromagnetic actuator that presses the clutch plates together can go bad, resulting in poor contact. The clutch plates end up slipping and cause a terrible noise and vibration because of the inconsisent load of the compressor trying to spin.