08 V6 P12A2 code and listen to engine sound...
 

All,

My 2008 cayenne V6 (130,000 miles) started throwing a P12A2 trouble code, which relates to fuel rail pressure. I did my research and it can be caused by many things such as bad fuel pumps, bad fp sensor or vacuum leak...

The symptoms are slight stumble of the idle when cold, and that is it.

Now, before I dump cash in replacing parts without knowing exalcty what is wrong, Imwanted to dig a little more in any other clues.

I noticed if I blip the throttle slightly enough there is "sqeak" noise that I recorded in the video below. Not sure if this is normal or not.

https://goo.gl/photos/sPhN9B3r5juuyhXR9

Also, when I shut down the engine, it makes a noise that is also suspicious:

https://goo.gl/photos/8K4co54HnPAdUJi36

Any help in pinppointing the exact problem will be greatly appreciated!

Usually on the narrow angle V6 (VW VR6) engines it ends up being the valve cover assembly. If you try to slightly lift the oil filler cap it'll be sucked down tight. Disconnect the large vacuum line, block it off and see if the noise goes away and you can lift the cap easier. Sometimes the line cracks but it'll usually set lean exhaust codes as well. Air/Oil separator is built into the valve cover. Replace both cover and line.

Kenneth,

Thank you so much for pointing me in the right direction. Indeed, I just found the exact same noise described on Touareg V6. Now, do you beleive the P12A2 code is caused by this valve cover issue?

2008 V6 3.6L throwing a "hissy" fit when you touch the gas - VIDEO - Club Touareg Forums