Porsche Macan Forum banner

21 - 28 of 28 Posts

·
Registered
2015 Macan S
Joined
·
28 Posts
Just back from a 3000 mile trip and I can conclude that it isn't the wheel bearing as the sound has not changed. It did become a knocking sound on a really rough section of road for a short while which makes me suspect that the exhaust pipe is the culprit.

I think the whole pipe is oscillating or moving and this constant movement creates this annoying sound. All the brackets are fine but the rear part of the system does have a fair bit of movement anyway.

I'm going to swing by a good exhaust shop in the new year to see what they think.
Interesting. Natural resonation is plausible, however unlikely to cause intermittent vibration. I would assume it would be constant (based on RPM).

Have you checked for play in your axles?

How old are your tires?
 

·
Registered
Joined
·
10 Posts
Exhaust shop says pipe is fine, flex joints working as intended. Tech there reckons is tyres but I'm not convinced as there is a similar 'warble'/pulsing sound at idle from the rear section of the exhaust (but may not be related and may be normal idle exhaust sound).

Haven't checked axles but will put it on the list when I go see my indy. Interestingly the front drive shafts were replaced by dealer at 30000 miles for the previous owner for an unspecified noise. But surely this would've got worse on the recent 3000 mile road trip? In fact, every wear item should get worse after that mileage but this sound has not changed at all!

Front tires are new, temporary budget tyres (waiting for Conti stock), and rears have about 5000 miles. Going to replace front tyres again next week as am embarrassed about the Radar tyres on the front (and they're noisy on anything but smooth tarmac). Then will start troubleshooting with my indy.

I still suspect it's exhaust related but can't replicate the sound on the lift as it happens or is noticeable under light engine load mostly.
 

·
Registered
2015 Macan S
Joined
·
28 Posts
Exhaust shop says pipe is fine, flex joints working as intended. Tech there reckons is tyres but I'm not convinced as there is a similar 'warble'/pulsing sound at idle from the rear section of the exhaust (but may not be related and may be normal idle exhaust sound).

Haven't checked axles but will put it on the list when I go see my indy. Interestingly the front drive shafts were replaced by dealer at 30000 miles for the previous owner for an unspecified noise. But surely this would've got worse on the recent 3000 mile road trip? In fact, every wear item should get worse after that mileage but this sound has not changed at all!

Front tires are new, temporary budget tyres (waiting for Conti stock), and rears have about 5000 miles. Going to replace front tyres again next week as am embarrassed about the Radar tyres on the front (and they're noisy on anything but smooth tarmac). Then will start troubleshooting with my indy.

I still suspect it's exhaust related but can't replicate the sound on the lift as it happens or is noticeable under light engine load mostly.
No, not on a small trip like that, unlikely as well, unless they were not seated properly during installation. Next time you have it in the air, check for rotational play. In/Out play is okay, rotational however, is not. Let us know if there is any change with the tire change. Cupping in the budget tires could also cause noises/vibrations.
 

·
Premium Member
Joined
·
3,923 Posts

·
Registered
Joined
·
10 Posts
Thanks, I have read all the threads on all engine noises in an attempt to solve this.

My noise is similar to 1 in the first thread but I have already replaced the flex joints with stronger ones as I initially had the marbles in a tin can noise. The humming noise actually started a short while after I replaced the flex joints. That's why I still think it's exhaust related but don't want to replace the downpipes as it is too costly here in South Africa. The Exhaust shop advised against wrapping the flex joints with a hose clamp (and didn't have big enough clamps in stock) but I might try it anyway.
 

·
Registered
Joined
·
10 Posts
Just a quick update to this. It's not the exhaust. I free-wheeled (engine off) down a gentle slope yesterday and the woo-woo noise is still there.

Checked axle in garage with car jacked up and the right axle is not 100% centered when the wheel is rotating slowly. Seems there's a tiny bit of "run-out" or wobble for wont of a better description (not sure if this is normal??).

No obvious bearing noise but there is a slight grinding for a small part of the revolution (not brake rub) which sounds like it's more from the inner CV (same area as the wobble is most evident). This is different to the running noise but worth investigating.

Hope it's not a faulty axle/CV joint as that's a pricey repair. SKF wheel bearings are relatively cheap (only $70 locally) so hoping it's that. Booked in at Indy for next Wed (13th) so will update after that.
 

·
Registered
2015 Macan S
Joined
·
28 Posts
Just a quick update to this. It's not the exhaust. I free-wheeled (engine off) down a gentle slope yesterday and the woo-woo noise is still there.

Checked axle in garage with car jacked up and the right axle is not 100% centered when the wheel is rotating slowly. Seems there's a tiny bit of "run-out" or wobble for wont of a better description (not sure if this is normal??).

No obvious bearing noise but there is a slight grinding for a small part of the revolution (not brake rub) which sounds like it's more from the inner CV (same area as the wobble is most evident). This is different to the running noise but worth investigating.

Hope it's not a faulty axle/CV joint as that's a pricey repair. SKF wheel bearings are relatively cheap (only $70 locally) so hoping it's that. Booked in at Indy for next Wed (13th) so will update after that.
Hi Tomy,

Thanks for the update! I am looking forward to hearing what the bearing does to change this. I would certainly remedy that first before swapping out expensive axles.
 

·
Registered
Joined
·
10 Posts
Still scratching my head over this. The indy (25 years at Porsche) ran the car on the lift and couldn't identify anything out of the ordinary. I thought I heard the sound faintly and it sounded like air noise around the tyre when in motion. The indy recommended I start by replacing the tyres, which I did with n-rated Continental Sport Contact 5's. There was an improvement in the sound at lower speeds (below 50) but no change at highway speeds.

I'm going to run these tyres for a few hundred miles (which might take me a few months since we're back in lockdown in SA) to see if the tone changes. If not, will fit the wheel bearings and take it from there. Sorry there has not been a resolution to this yet...but will keep updating if anything changes.
 
21 - 28 of 28 Posts
Top