Rattling/rumbling sound undercar

[Simonr23]

Does anyone else have this sound from their diesel Tiguan? It sounds a bit like an exhaust shield, but not quite. A bit like haldex noise, but again, not quite. It’s most noticeable at lower/mid speeds and low revs, but mid/high engine loads. It’s not obtrusive and to someone not anal about such things, may not even give it a second thought. I know it’s not meant to be there.

I can’t tell if it might be gearbox, a piece of metal rattling, or rear end(haldex) related.

From the drivers seat. It sounds like it’s coming from under the rear passenger seat area. But noises can come from random places and not be where they appear.

Also most noticeable when the car is fully warmed up(like after a 20+ min drive) but is always somewhat present.

Cheers.

Edit- dealer says they can’t hear anything when they drive...

[Dose Pipe Sutututu]

Does it happen only when you have some form of steering angle? like turning right or left and giving the car soem power?
Most noticeable is when you do a u-turn.

if so, it's just the Haldex, you can get VCDS or OBDEleven to set the Haldex to Quiet, which sends less power to the rear

[Simonr23]

No, mostly I notice it going straight. I’ve had a tiguan loaner and it had terrible haldex noise. This doesn’t quite sound the same(or as ‘rude’) it sounds a bit like diesel pre-ignition for all you old-school
Diesel fans, but again, not quite, and rearwards, rather than from the engine area.

[Dose Pipe Sutututu]

That's a tough one, do you have access to a hoist OR decent car ramps?

A visual inspection might be locate something

[Simonr23]

On the subject of haldex settings, does going into off-road mode revert the settings back to whatever it is meant to be, or is the car always front-biased after setting it to quiet?

[Dose Pipe Sutututu]

On the subject of haldex settings, does going into off-road mode revert the settings back to whatever it is meant to be, or is the car always front-biased after setting it to quiet?

When you put it into off road mode, I believe it's becomes constant 4WD so it physically locks the haldex (I also could be wrong as I've yet to test this scenario)

[vdubbed12]

Does anyone else have this sound from their diesel Tiguan? It sounds a bit like an exhaust shield, but not quite. A bit like haldex noise, but again, not quite. It’s most noticeable at lower/mid speeds and low revs, but mid/high engine loads. It’s not obtrusive and to someone not anal about such things, may not even give it a second thought. I know it’s not meant to be there.

I can’t tell if it might be gearbox, a piece of metal rattling, or rear end(haldex) related.

From the drivers seat. It sounds like it’s coming from under the rear passenger seat area. But noises can come from random places and not be where they appear.

Also most noticeable when the car is fully warmed up(like after a 20+ min drive) but is always somewhat present.

Cheers.

Edit- dealer says they can’t hear anything when they drive...

Mine’s a MY20 petrol Allspace and I heard it from Day 1 on the way home from dealership. As noise level and type can be quite subjective I find it hard to describe but the parameters that you mentioned fit exactly to when I hear the noise. Dealer/salesman who was very nice to give me a courtesy call told me it may be the “humming” noise from 4 Motion rear diff. Did the noise get louder over time? Or have you noticed anything concerning mechanically so far? I’m thinking of having a drive of demo cars later.


Edit: it may be a well known issue to dealers? He told me straight away as soon as I mentioned the noise even before I went into more details.

[Simonr23]

It hasn’t changed in 25000kms.

It’s not very refined, but perhaps it truly is characteristic of the various components used in the driveline?

Whether it is still unchanged at 125000kms...

[vdubbed12]

It hasn’t changed in 25000kms.

It’s not very refined, but perhaps it truly is characteristic of the various components used in the driveline?

Whether it is still unchanged at 125000kms...

Maybe it’s a characteristic if other cars also have it. You must have good ears if you can hear it in a diesel model - watching this YouTube video it sounds much cooler but also louder in the cabin.

I can also confirm it doesn’t really happen until the car is warmed up but probably not as long as 20 minutes. I haven’t checked the exact oil temp it occurs at but test driving at 11pm reproduced it before operating temp I think. Does it happen going in a straight line and gradually accelerating?

I read somewhere that a heat shield was bent and touching the propeller shaft and that’s about where it sounds like it’s coming from?

[vdubbed12]

I just had a quick look under the car and heat shield doesn’t seem to be bent anywhere along the propshaft but I’d have to have it on hoist to see better I guess. Towards the rear diff and near the fuel tank there is about a finger width between the propshaft and heat shield and even less above cat converter. I guess this heat shield would become quite flexible when the car is warmed up? I can’t see any paint off the shaft itself at this angle on the floor.


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