Should throttle body at rest be slightly open?

[Papagut]

I just removed and cleaned my throttle body as a step in trying to get a nice stable idle, and I noticed that at rest, the plate is slightly open. Here are a few pictures to illustrate it - is that a normal state? 

 

After cleaning it, and it was moderately soiled, I also attempted to reset the adaptations via Durametric. Following the instructions, it says that once completed, the final value will read 14 - mine started at 11, and after following the process - ended right back at 11. Not sure if that is related so I thought it best to note that too. No other significant errors present. 

 

Thanks, 

Mark

[deilenberger]

Normal. There is no bypass idle valve on a Cayenne - the throttle itself becomes the idle valve.

[Papagut]

Thanks for that information, I'll check that off my list of possible causes for my unstable idle issues. 

[bigbuzuki]

With a 2004 CTT, you may have aged vacuum lines that are leaking which can cause idle issues.

[Papagut]

I am thinking this is definitely a likely cause too. I replaced the ones running over the top of the engine a while back, they are all nice and intact, replaced the air-oil separator gasket, that has a nice seal now too, but the line that runs downward on the drivers side front of the engine - that is where I will look next. I think I will start a new topic specific to my idle issues with the codes that I am getting.  

[Papagut]

Just in case anyone comes across this thread trying to solve unstable idle issues, bigbuzuki was on the right track. I replaced the vapor canister purge valve, pretty easy and inexpensive, and the crankcase breather check valve, even easier. the purge valve may have been a contributor, but the check valve was the main culprit. What is interesting here is that all of my ventilation hoses were intact and without leaks, but if you peered inside the removed check valve, you could clearly see that the membranes inside had completely disintegrated. That immediately did the trick.