HD2pct

I am getting a VERY faint noise that is like a howling ("woo woo") occasionally when taking off from a stop. It's in a fairly low gear, probably 3rd or 4th or so. It's literally like wind noise vs drivetrain noise. but it's not wind, and I am wondering if this is symptomatic of a transfer case issue. I only bring that up because it's a common failure. I haven't had any driveability issues or "lurching" or any of that stuff that has been mentioned as part of the T-case issue.

Anyone have a theory on this? Am I looking at a transfer case and if so, what are the options there? I was thinking of waiting until it got worse to take it in because, at this point, you really need a sensitive ear to hear it.

Thanks for any input.

RAudi Driver

1. How old are your tires?

2. Does it do it in neutral. I know you said when you are taking off from a stop but then you state 3rd or 4th gear?

3. does it make the noise when brakes are applied?

4. how many miles are on the car?

HD2pct

Fronts are 2018. Rears 2019

It doesn't seem purley speed-related. It does it when I take off easily (which is most of the time) and at that time I am probably in gear 3 or 4. Slowing down to that same speed in another gear doesn't produce the noise

I am pretty sure that the noise would immediately go away if I touched the brakes to slow. This is something that I hear for like 1-2 seconds. It just seems to be more frequent lately

It's got 80k miles on it.

Thanks

leftlane

Kinda sounds like a wheel bearing - though I haven’t heard of many problems on the Cayenne. Also it would probably still be making the noise as you cruised. I’d also check over your tires to make sure there isn’t something obvious.

KBell

Vote for Tire.
Check the tread pattern.
When was last alignment?

HD2pct

Not sure about alignment. Tires are pretty new. It wouldn't hurt to check that in any case.

When this first started I was trying to see if I could hear it externally by running near curbs on each side with open windows. I could not. If it were a wheel bearing I think I would have heard that because bad ones are generally significantly louder outside the car.

I think I am just going to have to let this get a little worse so it gets easier to diagnose. Right now it's just at the stage where we nutty Porschephiles would hear it and any nobody else would.

RAudi Driver

Next time you're are taking off and it starts to make the noise, lightly press the brakes but not enough to slow the car down. Just enough to have the pads barely touch the rotors. See if that eliminates the sound. If it does, your pads are catching the rotors every rotation.

Radi

Maybe you hear a hydraulic system.

HD2pct

Well, dealer tells me that it's my front differential. I'm sort of surprised by that. I guess I will STFF and see what else has been posted about this.

We agreed that it would make sense to run with it for a while, as there is no "danger" involved in that. Before I spend the money to fix it I want it to be bad enough that I HAVE to deal with it. But I hate noises, plus I rarely am listening to the audio system.

jpru2001

On my old 955 I lost the front diff and it took 2 years to get from that initial noise to a grinding loud enough for me to replace it.
Also replaced it with one I found a reman on ebay for around $500 instead of the 4 or 5 grand Porsche wanted. Want to say it had some small warranty with it too.

HD2pct

Yeah I have been looking at options. I am finding used on ebay for about $1200-1300. Have not found a reman yet but as you say, I have time. Right now it sounds more like a resonance than mechanical grinding of any kind. But noises are funny like that.

BTW, I was quoted about $5500 by the dealer.

jpru2001

LOL I went through the same thing years ago. I want to say the one I bought came out of Romania or Poland or something like that. On ebay. It worked fine too and my Indy put it on for $300 I think. On the 955 at least I seem to recall if you bought the entire front diff assembly it was a pretty simple install of bolting it on and filling it up with fluid.