17 Pajero has whine/ hum noise on 4H

[liyunzhnen001]

Hi guys.

This is regarding to my 2017 Pajero GLX. I don't know when it started to have faint whine/ hum noise when drive on 4H on highway.

I only do service with dealer and only do recreational off-road driving seldomly.

Considering the car is relevant new, it might not be mechanical issue?

Do you guys have same experience? or it is normal noise?

Thank you very much.

[HeavyPizzaz]

See this thread mate

https://www2.pajeroclub.com.au/forum/showthread.php?t=14737

[JT8D]

Hi guys.

This is regarding to my 2017 Pajero GLX. I don't know when it started to have faint whine/ hum noise when drive on 4H on highway.

I only do service with dealer and only do recreational off-road driving seldomly.

Considering the car is relevant new, it might not be mechanical issue?

Do you guys have same experience? or it is normal noise?

Thank you very much.

I own a ‘16 NX and I’ve raised this issue in a few different threads. You’re not imagining things and owners of older models will not share your experience.
My best way of describing it is as though the engine mounts are grounded when in 4H. Pajeros I’ve discovered are not known for their quietness or smoothness and in 2H it is acceptable as opposed to when in 4H.
My investigations so far have led me to understand that it is most likely just second order engine vibrations (normal) that is being transmitted through to the body.
My question is: what’s changed in the driveline between the older models that don’t have this issue and the later models that do?
Sorry I can’t offer a solution at this stage. 2 dealerships have said to live with it! 😩

[HeavyPizzaz]

The thing is though mate that heaps of people have late models (mine is ‘16 like yours, with 96,000km on it) who don’t have this problem, so we shouldn’t be talking about it as if “later models have it and earlier models don’t”. The more appropriate question is why *some* later models have it yet most earlier models don’t. What is it about some that make this a problem? And my hearing ain’t bad either, I’m <40 and I can still hear mozzies in a room (the best hearing test) when my wife doesn’t.

[old Jack]

I own a ‘16 NX and I’ve raised this issue in a few different threads. You’re not imagining things and owners of older models will not share your experience.
My best way of describing it is as though the engine mounts are grounded when in 4H. Pajeros I’ve discovered are not known for their quietness or smoothness and in 2H it is acceptable as opposed to when in 4H.
My investigations so far have led me to understand that it is most likely just second order engine vibrations (normal) that is being transmitted through to the body.
My question is: what’s changed in the driveline between the older models that don’t have this issue and the later models that do?
Sorry I can’t offer a solution at this stage. 2 dealerships have said to live with it! 😩

I am sure it is a combination of the following that is causing the resonance that some people are detecting and it is more noticeable in 4H than 2H.

1.There was 5.6 % increase in final drive ratio in th 2016 NX, from 3.917:1 to 3.692:1.
2.There was no change in the auto transmission gear ratios.
3.There was no change in the AT ECU programming, so the gear changes are occurring the same engine rpm and transmission output shaft speed but the engine is at a higher load due to the higher final drive ratio. I can sense the engine is just outside its sweet spot. Also the torque convertor lockup timing remains unchanged and this make it worse when the TC is locked up.
4. When in 4H both the front differential and the viscous centre differential are now working under load.

I can detect the difference between 2H and 4H in both my PB CHallenger and Pajero 12's NW, both are fitted with Cooper ST Max tyre's so they are not a quiet or smooth tyre. I can feel and hear the effect of the extra driveline load between 4H and 2H at speeds below 70kph. I have spent almost 30,000kms really listening and feeling the transmission, engine and driveline relationship the PB Challenger as well as observing kph, rpm, engine load and instantaneous fuel consumption on the Scangauge, on my Challenger whilst testing both Lockup and Auto Mate. I noticed harmonics that Marshall from MM4x4 could not and these all tended to be solved by delaying gear up changes and TC lockup by as little as 1% or 2% in some situations.

Recently I up sized from standard diameter tyre's to oversized by an extra 38mm (5.5%) and this has dramatically changed the way both the factory AT program and Auto Mate are behaving. I have already had a custom retune of Auto Mate which has improved things but it will need to go back for more fine adjustments once I have quantified what is required. If I drive in manual mode then the harmonics are reduced substantially.

So my suggestion is if you have a 16NX onwards and can hear and feel the harmonics, try driving in sport manual mode and only change up gears when you are at 1600rpm for 1st to 2nd, 2200rpm for 2nd to 3rd and 3rd to 4th and then 2500rpm 4th to 5th. Do this on a very gentle throttle and hold the throttle steady on the gear change. You will also notice there is a considerable time lag between when you select the gear change and when the gear actually changes. Try this in both 2H and 4H and see if you can sense the difference.

OJ.

[JT8D]

The thing is though mate that heaps of people have late models (mine is ‘16 like yours, with 96,000km on it) who don’t have this problem, so we shouldn’t be talking about it as if “later models have it and earlier models don’t”. The more appropriate question is why *some* later models have it yet most earlier models don’t. What is it about some that make this a problem? And my hearing ain’t bad either, I’m <40 and I can still hear mozzies in a room (the best hearing test) when my wife doesn’t.

Thanks for taking up the thread on this issue. Glad you haven’t got this issue and it helps to shed light on the fact that 2 cars out of the same factory in the same year can be different. One operates optimally and one doesn’t.
I was only trying to provide some observations to another concerned Pajero owner and certainly not inferring that any Pajero owner was hard of hearing.

[JT8D]

I am sure it is a combination of the following that is causing the resonance that some people are detecting and it is more noticeable in 4H than 2H.

1.There was 5.6 % increase in final drive ratio in th 2016 NX, from 3.917:1 to 3.692:1.
2.There was no change in the auto transmission gear ratios.
3.There was no change in the AT ECU programming, so the gear changes are occurring the same engine rpm and transmission output shaft speed but the engine is at a higher load due to the higher final drive ratio. I can sense the engine is just outside its sweet spot. Also the torque convertor lockup timing remains unchanged and this make it worse when the TC is locked up.
4. When in 4H both the front differential and the viscous centre differential are now working under load.

I can detect the difference between 2H and 4H in both my PB CHallenger and Pajero 12's NW, both are fitted with Cooper ST Max tyre's so they are not a quiet or smooth tyre. I can feel and hear the effect of the extra driveline load between 4H and 2H at speeds below 70kph. I have spent almost 30,000kms really listening and feeling the transmission, engine and driveline relationship the PB Challenger as well as observing kph, rpm, engine load and instantaneous fuel consumption on the Scangauge, on my Challenger whilst testing both Lockup and Auto Mate. I noticed harmonics that Marshall from MM4x4 could not and these all tended to be solved by delaying gear up changes and TC lockup by as little as 1% or 2% in some situations.

Recently I up sized from standard diameter tyre's to oversized by an extra 38mm (5.5%) and this has dramatically changed the way both the factory AT program and Auto Mate are behaving. I have already had a custom retune of Auto Mate which has improved things but it will need to go back for more fine adjustments once I have quantified what is required. If I drive in manual mode then the harmonics are reduced substantially.

So my suggestion is if you have a 16NX onwards and can hear and feel the harmonics, try driving in sport manual mode and only change up gears when you are at 1600rpm for 1st to 2nd, 2200rpm for 2nd to 3rd and 3rd to 4th and then 2500rpm 4th to 5th. Do this on a very gentle throttle and hold the throttle steady on the gear change. You will also notice there is a considerable time lag between when you select the gear change and when the gear actually changes. Try this in both 2H and 4H and see if you can sense the difference.

OJ.

Hi old jack,
Thanks for taking up this thread and for your insights.
(Were the final drive ratios in your first point the other way around with the higher ratio actually introduced with the DPF at the end of ‘16?)
When coasting in 4H my NVH is not so apparent as under acceleration up to about 2500rpm. A sweet spot seems to be found after that but then the auto changes down to the engine’s harsher zone.
I understand that the front diff and viscous coupling are under load in 4H but there’s obviously a path with these 2 components now in play whereby the engine vibes find a way in to the body for this resonance to be felt and heard under engine load.
In 2H I also have a resonance with the t/c locked up between 95 and 100 kmph. This speed and engine rpm co-incidence is amplified just prior to the auto sensing any engine load and unlocking the t/c which then kills the increasing resonance instantly.
4H is the biggest let down of my Pajero ownership! As a result I don’t use 4H on bitumen until absolutely necessary and don’t enjoy driving it at all in this mode. I’m in 2 minds as to whether or not to keep this car and luckily keeping the mileage low is not going to be a problem. I can’t believe how rough it is in 4H. Where do you take a car for a second opinion and use that as proof that there is something not right that the dealership is obliged to fix?
This thread has certainly helped to provide that atleast one ‘16 NX owners experience is vastly different to mine.

[old Jack]

Hi JT8D,

I would suggest you drive another 16+NX and seem if you can pick up the same problems. This will tell you that you do have a problem with your car or it is you that is ultra-sensitive to harmonics. I do not say this in a negative way, just as some people have an ear for music, pick up languages easily or excellent hand eye coordination, you may have a heightened sense of awareness to vibration and harmonics.

If it is you, then there is one thing you could try before deciding the Pajeo NX is not for you. Try fitting a MM4x4 Auto Mate controller, these have several steps of adjustment so you can change the behaviour of the up and down gear changes as well as the torque convertor lock and unlock. This will not fix the underlying problem of over gearing but it will reduce the noticeable effects of it.

Will it be enough for you to be satisfied and keep the Pajero, only a test will tell.

OJ.

[JT8D]

Hi old jack,
That is a logical suggestion for comparison. I plan to ask my dealership exactly that but it could be difficult for them to provide.
I recognise that there is a matter of subjectivity in something like this but this is an obvious and clear increase in NVH under acceleration in 4H on city roads.
I’ll keep your other suggestion of the lock up kit in mind but want to press the dealership and MMA as much as I can on this first.
Thanks again for your interest and empathy.

[liyunzhnen001]

I own a ‘16 NX and I’ve raised this issue in a few different threads. You’re not imagining things and owners of older models will not share your experience.
My best way of describing it is as though the engine mounts are grounded when in 4H. Pajeros I’ve discovered are not known for their quietness or smoothness and in 2H it is acceptable as opposed to when in 4H.
My investigations so far have led me to understand that it is most likely just second order engine vibrations (normal) that is being transmitted through to the body.
My question is: what’s changed in the driveline between the older models that don’t have this issue and the later models that do?
Sorry I can’t offer a solution at this stage. 2 dealerships have said to live with it! 😩

Thank you very much for your sharing,mate. As long as it is not mechanic issue, I am quite settled.

The old adage goes: you get what you paid for. Unless I have 80K to go for a Y62 patrol or a high spec prado with rear diff lock, I am still gonna choose pajero if I would be asked to choose twice.