pajero engine vibration

Submitted: Friday, Jun 15, 2007 at 13:51
ThreadID: 46696 Views:6928 Replies:2 FollowUps:2
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I have a NM series Pajero with the 3.5l V6. There is a noticeable vibration from beneath the driver side floor when the revs are about 2200 in or out of gear.It has nothing to do with driving just reving the engine. I don't now whether it is exhaust system or something is out of balance on the engine. Any suggestions or has someone else experienced this
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Reply By: Sea-Dog - Friday, Jun 15, 2007 at 15:20

Friday, Jun 15, 2007 at 15:20
There are so many variables but having that the car does not have to be driving I would say that it will come down to one of a few things..

The first thing that I would be checking is engine mounts.. I would be surprised if it is anything other than this.

The second place I would look would be the clutch.. hard to diagnose correctly though but I would sit the revs at the vibration range and put the clutch in and see if it changes anything... if it is auto then this obviously wouldn't be in the equation.

Spark plugs or other connection would be down the list there somewhere but easily played with to discount from being the trouble maker.

Sorry but that is all I have to offer on the info I got..

Cheers
AnswerID: 247056

Follow Up By: skipintara - Friday, Jun 15, 2007 at 15:37

Friday, Jun 15, 2007 at 15:37
It is an automatic. Why do failed engine mounts bring out vibrations at selected rev's?
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Follow Up By: Sea-Dog - Friday, Jun 15, 2007 at 16:34

Friday, Jun 15, 2007 at 16:34
The engine mounts act as shock absorbers of sorts for the motor and gearbox etc.. in essence the bits of the motor are all spinning and changing directions and all that so there will always be a bit of vibration even from the best of engines.. most of the time we don't notice it as the rubber on the mounts basically soaks up this vibration.

With the engine it could well be that at certain revs the rythym of the pistons and other moving parts might just line up so that a vibration is sent through the motor.. a broken mount will not soak up this vibration and you will start to feel it.

Get a small wrecking bar in and wedge the engine mounts around a bit.. you should have some but not a lot of movement in there.... Most motors tend to break the passenger side mount first as this is the side that tries to twist upwards under acceleration..

If nothing else you could always look at changing them out anyway if you are half mechanically minded as it is an easy job to do and the mounts are generally very cheap anyway... $25 as side or so.

Best of luck with it.
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FollowupID: 507889

Reply By: Boobook2 - Saturday, Jun 16, 2007 at 09:27

Saturday, Jun 16, 2007 at 09:27
I had a "tinny" rattle sound with vibration on my NM at 2000 to 2100 rpm. Same sort of situation as yours. As you rev'd through the range you could hear it, especially under light load. It slowly got worse so I could hear it in neutral.
It turned out to be the head shield on the exhaust under the firewall on the passengers side.

hope this helps. Mitsubuishi had no idea.

Eventually I "fixed it" by bending it ever so slightly with a screw driver which stopped the resonation.
AnswerID: 247197

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