So we have had our new 2012 Journey SXT 3.6l for about 2 mths and 2500km. For the last month or so we've noticed a shake in the vehicle when it idles. My wife notices it more when it first starts, it is very noticeable after it warms up and sitting in a drive thru for more than a few minutes.
We took it in and of course no one noticed it, went to Tim Horton's after leaving the dealership and it was so noticeable I was more than a little po'd at the dealership. I called our sales guy, he wanted to see it so I took it down to him and he noticed it (not at it's worst mind you), he seems to think it's because we are using 87 octane gas and suggested going through a full tank of Shell V-Power ( or whatever the best one is they have) and then going to a mid-grade from Shell. I've been reading using the 89 octane will give us better mileage and performance so I will likely switch to that. My wife is furious though and thinks the salesman is full shit and feels like we are being treated as nit-picky (we've had other problems, that the dealership either didn't see or said they fixed and didn't).
Can anyone confirm that 87 octane would cause a rough idling? It's going to take us months to burn through 2 full tanks of gas and I'm concerned we are being brushed off.
Thanks for any input.