Rich34

Hi. I own a 2004 Cayenne Turbo with 55k Miles. Only problem Im experiencing is when I start the car, occasionaly this loud noise comes from the engine compartment. The description of this noise is like air coming out of a pressured hose or some kind of a belt noise. It's ridiculous sometimes when their are people around the car to hear it because it's so loud. WHAT IS THIS FROM????? Someone mentioned it's the charcoal canister, could it be?

C4SJOHN

Maybe it's a loose hose or fitting for your air ride system ( shocks ) trying to pump air to them for low pressure during the start up process....

Rich34

Im sure its not the suspension. It's an irregular start (especially in warm weather) that causes this to happen. I thought it's the battery that cause it to slow start, but I replaced both of them and it doesn't go away.

Rich34

Any other suggestions?

yeldogt

Is this happening as the car is starting -- like a failing starter motor? Or it in happening after the car is running like a failing water pump?

Slow Guy

Troubleshooting noises you can't hear is very difficult. Just from your description of it being at startup and sounding like an air pump I wonder if it might be from the SAI pumps (up under the windshield in the engine compartment). The pumps pump air into ?? for the first 2 min after the vehicle is started, this is an emissions related operation. You may have a hose loose.

There are actually 2 "air pumps", 1 for each bank of cyls. and 1 "secondary air pump" IINM.

Just my uneducated guess.

To see if it is the air ride system I'm guessing you could raise/lower the Pepper with the system (after the vehicle is warm) and see if you hear the noise then?

Rich34

This noise is instantaneous and stops right when the car starts. Is the charcoal canister a problem with these cars?

awcayenne

starter after coolant leak

Kevin M.

Is this it, if so its the starter as stated

ArneeA

I was thinking secondary air pumps as well but those would throw codes, not just noise.

Dax

My Cayenne has been making this noise for the last 8-10 months...

The coolant pipes were replaced way back in 2010 after a leak, and according to my local Independant Porsche specialist it is indeed leaking coolant which has caused this...

Car starts first time on every occasion and the noise only happens intermittently...

He has said that he knows of Cayenne's to still be starting fine with this noise for 2+ years, so as I know replacment of the starter motor is a big job, I'll leave it for now and hope it doesn't fail... (touches wood...)

Km1.8t

It is your starter, common problem especially in colder weather.

din888

I have a similar problem now and I suspect it's the air pump. I placed a finger on the right hand side pump and it did vibrate more (which I suspect makes the louder noise). Thank you.

v10rick

Since the videos in thread have expired you should include a sound clip.

My 04 S made a brief kazoo sound at startup, that was caused by the starter.