2006 Cayenne Turbo - Strange tapping/knocking sound from Front Drivetr

[e36bmer]

I have 140k miles on my cayenne and have kept up with it really well.  I've already replaced the cardan shaft busing with an EPS one and replaced the front control arms about 30k miles ago.  

 

I'm not sure if it could be related, but a week ago I changed my front pads (eps yellow) and rotors (x-drilled) and within a few days, I started hearing this really strange sound.  It almost sounds like I have a baseball card sticking in my wheel spokes, but more metallic and off and on.  Sometimes it'll make zero noise, other times, it's a loud, tinny pop, like tapping a tin can w/ a knife. (usually decel) and others it's more of a deep thump, as if you tapped the diff case w/ a hammer (accel).  It follows road speed and not engine speed and sometimes it will stop when I get past a certain speed, others it just gets really fast.  Also, I noticed today, when I was at about 60mph and accelerated around a slow car, I felt a vibration through the throttle and maybe even steering wheel a little. 

 

I thought it could be with my brakes, so i took them back apart, inspected everything and put it back together, wiggled the suspension all around and turned the wheels (no wiggles anywhere).  The only sound I could hear was on the drive shaft that goes from the transfer case to the front diff, when moved back and forth, there would be a metal-on-metal click on the transfer case side, but it sounded different enough from what I was hearing when driving and that it should be under constant load and not the cyclical load i'm hearing. I think that isn't the issue.  The noise had stopped for 2 days afterwards.  Then, today it starts again.  I hear no change with turning of the wheels or height of the car, or any change if and when I depress the brakes.  

 

I'm baffled.  I tried getting a video if it, but just my luck when I had my friend to record the sound, it wasn't doing it.

 

Any Ideas?

[wvicary]

Brake rotor backing plate hitting rotor? They can easily be bent and contact the rotor.

[e36bmer]

I took a look there, it doesn't seem to be the issue. Maybe I'll take the rotors back off and check very closely, but I'm thinking maybe it's in the diff or is a cv joint.

[e36bmer]

Turns out it was the front drive shaft. The CV joint by the transfer case was trashed. I guess 140k hard miles will do that.

[gravityalwswins]

I think I might be experiencing the same issue. The noise seems to be coming from front running gear,( at first I suspected Cardan). The noise is more prevalent when moving at slow speeds and coming off the throttle. When brakes are applied it seems to almost disappear. Any further info from your experience would be appreciated. Was it the right/left side?, the drive shaft from transfer case to front diff? Also, where did you get your replacement axle shaft from?

Thanks in advance

Edited March 24, 2015 by gravityalwswins

[gophaster]

Old thread but bumping this up bc I am having similar issue. 05 Cayenne Turbo is making a tapping sound mainly on deceleration (when I let off throttle) at lower speeds. Sound seems to be coming from passenger side front wheel area, happens when driving straight ahead. Seems to be quieted by application of brakes or driving in lower height with air suspension.

 

About 2 years ago I did the "Jimi fix" on the cardan shaft center support and that is still intact. Sounds like it could be drive shaft related but doesn't really sound like it's coming from center of truck.

 

Not seeing any visual damage to driveshafts or CV shafts/joints at wheels. Any ideas?

 

Thanks in advance.

Edited March 18, 2019 by gophaster

[cayenneturbo]

I am getting the same sound.  Whenever it happens and I quickly hit/release the brakes it goes away.