I have begun to notice my 09 LS 2.2 has developed a motor vibration at idle in park & idle in gear. The air intake assemly bounces front to rear and when you put both hands on it to "stop" it you can feel the vibrations though the cover as well as when you touch any part of the motor & tranny. (Had it also running while it was on ramps and was underneath). I have an INNOVA 3130 with live data and I noticed the RPMS in park idling bounced between 657 & 692 (no surging because the bouncing of numbers was in split seconds) and the timing auto adjustment was doing the same between 8% and 15%. There are no hard codes or pending codes, and the car has all systems at green (inspection ready). Any Ideas?

 

Is your AC on?
Defroster setting?
Simplest solution first.

 

What about when you change from P to R or D? Could be an engine mount.

 

Could be in Park, Neutral, Rev, Drive with my foot on the brake (such as at a light). Looked at the mounts (did not remove to look at) and from what I could see they weren't broken or cracked. Could the mounts be that much of an issue at 29,800 miles?

Oh-AC was off, DEF was off.

 

I'm thinking maybe the throttle body is in need of a clean, or maybe a camshaft solenoid is starting to act up. Has it set any codes?

 

No codes-hard or pending. Throttle body was cleaned not too long ago.

 

Hmmm, only 29,000 miles is awful soon for engine mounts to go bad, not unheard of though. The unstable idle and fluctuating timing suggest something is off somewhere, but it should be setting a code of some sort.

You should still be under warranty, maybe a trip to the dealer is in the cards.

 

Looking through the service manual here are some suggestions as to the causes of a rough idle like you've described.

1. Faulty or corroded grounds on the ECM module.
2. Contaminated fuel, either by water or alcohol.
3. Damaged or contaminated Oxygen sensor.
4. Improper EVAP system purge condition.
5. Improper fuel pressure.
6. Leaking or damaged fuel injector/injectors.
7. Kinked or leaking vacuum lines.
8. A large vacuum leak.
9. Improper spark plug gap, or damaged plugs.
10. Broken valve springs or sticking and damaged valves.
11. Camshaft position sensor/solenoid damaged.

But most of these conditions would set up a code or codes. I'd probably start by pulling the plugs and checking them, and checking for a vacuum leak too.

 

mmmm, that reminds me a similar issue that I had on a Mercury Sable, and this was the cause....

 

Well I had made an appiontment for 10/10 in the AM to bring the car in, weel now it's going in Thursday AM instead. Car bucked, surged, & crapped out in the middle of traffic on the Belt Parkway in Brooklyn on my way to work. NO CODES THROWN OR CEL. WTF!?! Restarted & bucked of parkway into a McD's lot. Hung for 1/2 hour & then restarted. Car ran fine as I was trying to get home when a CEL came up. Then the ESC/Traction Control lights. Called OnStar who stated P0014-Exaust Cam Sol. Less than 30,000 on car...

Guess the issue found me. I'll have to ask if they will change the Intake Sol as I am sure if they don't I'll be back again soon.