alpesh26

I seem to be getting what sounds like an air leak ('puffing' noise) from the left side of my engine. On idle, you can hear a constant pfft, pfft, pfft, pfft noise from around the throttle body area. I was able to get a video of the engine at idle.
When I push the throttle, I can hear what sounds like air escaping before the engine revs, again this seems to come from the left hand side of the engine. Sometimes, you can hear a clicking noise just before the engine revs when pressing the throttle. I tried to get a video of the air escaping on throttle but I couldn't really capture it, but at the 7-9s mark on the video below, you can hear the clicking noise. As it seems to be from the throttle body area, I'm unsure if its the flap within the throttle body causing the noise. I have tightened up all visible hoses and I couldn't find any splits.
Generally, the engine sounds a bit rattly like an older diesel. I've had the serpentine belt, tensioner with idle pulley assembly replaced and got my indy to check the pulleys in that area and they said its all fine. Throttle body was also cleaned. The rest of the car seems solid apart from the harsh downshift when hot which is the gearbox valve body.

I'm likely to get this noise checked out by my indy, but I wanted to check here to see if the sound is normal before I take it in. The engine seems to perform as normal and I've not noticed any power loss or sluggishness.

The car is a 2008 957 3.6 V6 with around 68k miles on the clock.

alpesh26

All sorted. The brake vacuum hose had perished and cracked in several places due to heat. New hose fitted and now no more noise and the brakes feel better.

Cdroot

Hello! I have this exact same sound! Do you think you could show me where this part in the engine bay it is? I'm going to fix it myself. Thanks!

alpesh26

Unfortunately I no longer own a cayenne so I can't really show you. IIRC it was towards the front of the engine bay on the left hand side under the black plastic trims. Definitely get the hose changed as you don't want to be losing your brakes!! I do miss that money pit though!

Cdroot

Lol thanks! I'll figure it out. Nice to see you're still an active member. What car did you get? And did you have a lot of problems with your cayenne?

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alpesh26

It was just old, the Abu Dhabi heat wasn't kind to it and the previous owner(s) had lapsed some of the maintenance. I left the country and moved back to the UK so I have an Audi A5 Sportback 2.0TDI quattro now - i miss the noise the v6 in the Cayenne made. I'd probably still have the Cayenne if i hadn't moved back

Douglas61

Thanks alpesh26 for the explanation. How would a bad brake hose make such a sound even when the car is not moving? My 2008 v6 Cayenne has a very similar sound and it also blows a bit white smoke.