Driveline Grumble or Groan in 5th 3.0 D4

I tried it, a couple of times, even though I suspected the oils weren't up to temperature but couldn't induce any noticible slip with increasing throttle from 1400 rpm. On 1 occasion kick-down to 3rd occurred at around 1800 rpm at or close to full throttle but no slipping prior to kick-down. Being a dirt road there was some tyre noise but normally being very aware of any torque converter slippage I considered there was nothing significant in this exercise. 135K and still haven't changed the gbox oil.

Thanks Graeme,
The noise I am getting is in command shift/manual in 5th gear not when in auto.
Thanks for trying it in your vehicle, it would be interesting if it happens in yours!
Talby

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Originally Posted by Talby

Thanks Unseenone,
I will pass onto the mechanics, would it be worth trying to get them to change the trans fluid?
Talby

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I doubt it, if it turns out to be bad, it is bad. There are reman ones on the market, but if it is under warranty, it seems like they just need to diagnose it and fix it up.

Perhaps it might be a worthwhile effort to have the fluid analyzed though.

Probably they should fit a set of chassis ears on it, and run it through the paces as well. Sound travels through the frame on these, and it can be difficult to pinpoint problems without it sometimes.

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Originally Posted by Talby

Thanks Graeme,
The noise I am getting is in command shift/manual in 5th gear not when in auto.
Thanks for trying it in your vehicle, it would be interesting if it happens in yours!
Talby

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My test was in command-shift 5th.

Thanks Again Graeme,
I forgot the transmission can override your gear selection if required.
Looks like mine has an issue, goes in Thursday morning !
Cheers Talby.

Hello
Made the mistake of trying it with ours, my goodness what a racket. Don't like the sound but have no idea what or where its from.
Cheers
Steve

Mine normally makes an induction racket on significant throttle at very low revs - around 1100 rpm in manual mode, but didn't starting at 1400.

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Originally Posted by Graeme

Mine normally makes an induction racket on significant throttle at very low revs - around 1100 rpm in manual mode, but didn't starting at 1400.

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Apologies if this is slightly off topic.

Hi Graeme.

What do you mean by induction racket. The reason I ask is that I've noticed what I would call a labouring sound/feeling as though the car needs to change down but hasn't. Funnily enough it is at 1100 rpm hence this question. Mine happens if I am cresting a rise or slight hill in auto and I was wondering if it's the auto not downshifting as it maybe should. I first noticed it with cruise control on but it does it with it off too. I am not accelerating or anything just keeping the throttle steady and if I push the accelerator it downshifts or if I use the paddle and manually downshift the grumbling goes away.

Martin

I expect mine's induction noise is from turbos working overtime coupled with having a snorkel fitted so that the induction noise is just outside the window. Labouring/vibration at 1100 rpm is not unexpected considering the crankshaft is turning at less then 20 rpm / 60 combustions per second - rather like the 50Hz hum from household electrical devices. These engines seem to be willing workers at low revs but I try to avoid other than light loads, keen not to decrease longevity from possible excessive bearing and piston skirt/bore loads.

I think at 1100rpm your crank is rotating at more than 20rpm.