Vibration on NS Petrol

[athino]

Over the past few months a slight vibration was evident when the car was cold and at certain speeds, which corresponded to somewhere 1500rpm and 2000rpm. Didn't think much of it but more recently it became fairly evident when the car was cold.

Booked it for the 15000 service approximately a month ago, just before going to the snow, and when my wife took it in and told them the Sydney Mitsubishi Mechanics most likely thought that it was just another non-mechanically minded wife telling them of "stuff" happening in a car that was likely her imagination (although they were polite enough not to show it).

They took it for a drive and put it up on the hoist and sure enough, vibration at that speed. They hadn't heard of it happening before so they discussed it with Mitsubishi who had heard of one other instance. Since the snow trip couldn't wait they did the rest of the service and told us they would research and get back to us. This is where you normally say "Like that'll will ever happen..."

The snow trip was great and as soon as I get the chance I'll post a couple of photos. Icy road, flat accelerator and it still found grip in all wheel drive.

Last Thursday we received a call from them telling us that they had a Mitsubishi Mechanics conference (or whatever the equivalent would be called) on the previous day and the problem has been reported at other dealers. A component on the transmission which is meant to cut vibrations is instead exacerbating them. They ask that we bring the car back and they will remove it however this will be a temporary solution while Mitsubishi Japan looks for something more permanent. So the missus took it back on the Friday and they removed this component and now the vibration is almost gone. A slight vibration still takes place between 2500 and 3000.

If anyone else has experienced this then there is a pseudo fix however it may not yet be widely known to all the dealers.

I need to add that the guys at Sydney Mitsubishi have so far exceeded my expectations...although I will be keen to find the permanent solution.

[matthewfnorbert]

i imagine they are referring to a 'tuned mass damper', which clearly means they have had a vibration issue at a certain single frequency (not uncommon). it is designed to vibrate 180 degrees out of phase relative to the problem vibration (normally resonant) therefore canceling it, if tuned incorrectly (wrong lenght or mass) then it itself may be excited into it's natural frequency (resonant vibration) and cause vibration. a good indicator that it is 'resonant' rather than a forcing frequency (like unbalance or alignment etc) is that it only happens at certain revs.

maybe the aussie engine/gearbox mounting stiffness etc is different to the engine/gearbox used to decide on the appropriate tuned mass damper..or even a swb verus lwb.. it will be something like that. in any case the local mm guys will need to get the good oil from the design engineers on solving the issue.

also it could be as simple as your tuned mass damper may not have been fitted correctly (slightly loose).

might have a look at mine and see if they are adjustable in any way

did they give it to you? do you have a pic?

[Proudy]

Over the past few months a slight vibration was evident when the car was cold and at certain speeds, which corresponded to somewhere 1500rpm and 2000rpm. Didn't think much of it but more recently it became fairly evident when the car was cold.

Booked it for the 15000 service approximately a month ago, just before going to the snow, and when my wife took it in and told them the Sydney Mitsubishi Mechanics most likely thought that it was just another non-mechanically minded wife telling them of "stuff" happening in a car that was likely her imagination (although they were polite enough not to show it).

They took it for a drive and put it up on the hoist and sure enough, vibration at that speed. They hadn't heard of it happening before so they discussed it with Mitsubishi who had heard of one other instance. Since the snow trip couldn't wait they did the rest of the service and told us they would research and get back to us. This is where you normally say "Like that'll will ever happen..."

The snow trip was great and as soon as I get the chance I'll post a couple of photos. Icy road, flat accelerator and it still found grip in all wheel drive.

Last Thursday we received a call from them telling us that they had a Mitsubishi Mechanics conference (or whatever the equivalent would be called) on the previous day and the problem has been reported at other dealers. A component on the transmission which is meant to cut vibrations is instead exacerbating them. They ask that we bring the car back and they will remove it however this will be a temporary solution while Mitsubishi Japan looks for something more permanent. So the missus took it back on the Friday and they removed this component and now the vibration is almost gone. A slight vibration still takes place between 2500 and 3000.

If anyone else has experienced this then there is a pseudo fix however it may not yet be widely known to all the dealers.

I need to add that the guys at Sydney Mitsubishi have so far exceeded my expectations...although I will be keen to find the permanent solution.

I am getting this vibration at 2000rpm...good info/feed back - my car is in tomorrow moring to have look at this issue + a few otehr things.

[John M]

Reading this I can only conclude that the drivetrain harshness I experienced during the two test drives (see my thread re NVH) is related. I'm very interested to hear of developments re a permanent 'fix' before I decide to buy one of these...

[matthewfnorbert]

mine does not do it... the one i test drove did not either

[athino]

matthewfnorbert,

It was the first thing I asked the missus when she brought it back from the Mitsubishi mechanics. Unfortunately she didn't ask for the item so I do not have it.

John M,

This developed over a number of months. I am happy with the Mitsubishi response and I can see they are working on it.

Regarding the vehicle, this is my third Pajero (NM, NP, NS) after driving all the vehicles in that class each time I went to renew. I would recommend them to all and sundry. Ultimate choice is individual and something that suits each persons needs.