Hi,
The M112 V6 should idle smoothly. See the website below for a
review and coin vibration test. My 2005 idles so smoothly, if the tach needle didn't show it, I wouldn't even know the thing was running!


http://www.whnet.com/4x4/new_V6.html

 

I did test drive a crossfire once. The first time I drove it (with the salesman inside) it started to idle rough. It was clearly not normal. He fixed the problem and told me it was just a vacum line. I didn't want to buy the car I bought a different one

 

I tried filling up with Chevron and so far the idle doesn't feel that rough.. Before I used Mobile. Where is the vacuum line located? So I can check it this weekend..maybe that will smooth out the rest of the engine..

 

I think I found the leak.. its on the drivers side towards the headlight area...but, I am not sure which line is leaking.. I do hear a strong hissing sound..

 

2005 18K miles, I've noticed the same thing in the past few months. Its not all the time, but I do notice it only at lights at idle. I'm assuming its the gas, I'm out in CA and never had this before in CO.

 

My 06 Roadster had a rough idle and it took the dealer a while to determine the location. It was a vacuum line and they told me it was under the engine cover. I have never had an idle issue since the fix and I will tell you the difference is night and day! So; if you think you have a rough idle problem; you have a rough idle problem. I have not noticed a difference in the idle due to gasoline manufacturers. I'm using premium grade primarily from Marathon, Sunoco and BP.
I hope this helps!

 

Any idea where under the engine cover that line was?

 

Ours idles a little rough as well (2005 Roadster Automatic 27,000 miles) but car just runs great - no stumble off idle. flawless power and gas mileage if also very good. Plan to just leave it alone until a plug change is needed.

 

I have a 2004 coupe (automatic) with 55K miles. I am getting a vibration when it is changing from 1st to 2nd gear. It just started about a week ago. It only happens when I accelerate. Any ideas? I plan to take it to the dealership service department this weekend.

 

I have 92,000 mile on my xf and it ticks for a few seconds at start and then goes away almost like low oil or no lubricate was present at start. It doesnt tick after a few seconds of running. I also have a little shake at lights but it doesnt stumble or hesitate. its seem this is happening on cars with as little as 250 miles on them and still happening on a car like mine with hight miles so maybe its just how the cars are and that could be a good thing.

 

mine idles smooth as glass 04 , auto with 23,000 on her !!! Cant believe how low the idle is but still nice & smooth !!!! U all better start checking this is not normal for sure !!!!!!!!!!!!