UGH! Sorry to hear that and been there, done that. The factory knows about this common defect and refuses to help. Perhaps we should all start logging this situation and discuss this with an attorney? You are the fifth person that I know of with this common defect.


Again, sorry to hear of your troubles (Dr. D, PAY ATTENTION HERE!). Odds are they'd doing the engine out, fixing a few other known defects (while in there) and changing a wire assembly (also a known problem) plus new fluid for (don't have my service sheet with me at the moment as could give you all the parts #s).


Just wait until you see what they charge you just for that smallish hose part...

 

That simple part cost me just over £200 UK at the main dealer. Plus the cost of the engine out work which added another £3,700. Ouch!
Here's a picture of said part, arrowed;

 

Hey guys how can the vacuum leak be bad enough to cause rough idle one day and not the next 200 miles?

I is try-ng my best to "pay attention" massa but I is slow.

I might just let mine idle rough and tell everybody I did a cam job.

 

Did the dealer provide a print-out of the diagnostic run that indicated the vacuum leak? Did the dealer do a smoke-test? With this much money involved, I would want some hard proof of the problem. Did you ever recycle the CEL (as I previously recommended) to see if it came back on? I'm not suggesting you don't have the problem, but the symptoms you mentioned previously don't necessarily fit with the diagnosis.

 

I cleared the fault with an OBD2 reader, and the 2574 and 1411 (secondary air flow) came up. The dealer charged me $360 for the vacuum test, so I assume it's legit. I assume the rough idle was a result of my oil cap being loose. When the cap was loose and I had the rough idle, I had codes 0300 and 0307-0312 (all 6 plugs on the left side of the engine misfiring). After I secured the oil cap, these all went away and stayed away, as did the rough idle. Having driven it since then, the only thing I noticed is that it seemed to stumble the one time I accelerated hard. I didn't to push it, so I did not try and recreate it. The dealer says that this vacuum line is also involved in the brakes, so it could possibly be dangerous. He also told me that this was not common, and they did about 1 of these a year at the dealership. Sorry to ramble, but I've also seen that this was a known fault through early 06 models, and I have an 07. I REALLY don't want to have the engine taken out of my car!

 

Thanks for all the help guys. I have only had this car for 3 months, and am new to it. I am mildly mechanically inclined, but every time I look at EXSF's engine out pictures, I get dizzy and feel faint.

 

Yes. In the GTC is was fine, then rough idle/stumbling followed by check engine. I reset and all was fine for a day or so and then stumble, rough idle, check engine light.


ALSO, remember how when I FIRST got the GTC I noticed that the engine's output power was a bit amiss as compared to the pervious GT. I BET YOU it was due to this known false air problem due to defective hose/assembly. You see, the computer allows for SOME air problems until it hits a certain percentage. Once you hit that percentage the engine mgt system comes into play and BOOM, you're $,$$$crewed.

 

That makes sense.

 

An update on my 07 GTC. I have been driving with a check engine light for the vacuum hose since February with no problems. If I reset the CEL, it comes back on within a day so I know the leak is still there. At some point I am going to have to smog my car, which I will not be able to do with the Check engine light in California. Any recommendations on a shop that can fix the hose for a reasonable rate on the west coast?

 

The Engine out Vacuum leak repair I did was less then half of what you were quoted. If you find a creative technician at a repair shop by you,I am sure they can fix it with out removing the engine. Since the mid 2006 cars and up do not have the same problem the early cars had. There are lots of areas to check once smoke tested and you can gain access through the rack and pinion area.

 

...gamocles...just read your problem issues on 07 GTC you got from San Francisco Bentley...have had considerable experience there...
...Where did you finally have work done and hope things settled down...you have had your share...JimB

 

This was one of the faults too (2ndary air) I had, finding out I was having leaks. But? on a 2007 isn't the source of the leaks right behind the engine and not on top of the transmission. (see Johnnys post)

https://www.6speedonline.com/forums/...ml#post4606701

That being said, you may ave vacuum leaks behind the steering rack too

 

....isn't the answer...depends if early 07 run or later when plumbing was moved...Bet there are 10,000 2004 through early 2007's out there...all either needing or having had engines out to replace defective plumbing...VW screwed their customers on that one...Are you ready for the San Francisco Bentley Service telling customer his was first one they saw...that they only do one engine out a year...Believe that and I have a bridge I can sell you...JimB