Engine vibrates quite a bit when parked and idle, what can be the cause?
 

Just got a 2013 XJL Portfolio AWD recently. I noticed the car vibrates quite a bit when it is parked and the engine is on. I thought it is a problem because my other car, a 2012 Cadillac SRX, vibrates much less in the same situation. What are the things I should start checking for the vibration?

Thank you!

Maya, my understanding is that the motor mounts on the car are what are referred to as active mounts. Ie, they are going to try and absorb the vibration to make the motor appear to be completely smooth. If the circuit controlling these does not operate correctly, it can cause the motor to appear to idle rough. I saw this on my car a few times, but after another start or two, it would go away. So, I never figured out what is going on. It may be possible that if you have the factory battery still in the car, the low voltage is causing things to act up. Then see what you have at that point.

If you look at the air intake bellowed sections. The pleats should be evenly spaced. If the bellows are pinched at the top then your motor mounts have collapsed by losing the hydraulic fluid and, therefore, the vibration you feel. I recommend replacing the 2 motor mounts and the transmission mount and life will be sweet again.

Could be an air leak - watch fuel trims to see.

The 3.0 L V6 in our cars is not glass smooth at idle as other makes. I also have a 2013 Portfolio AWD that vibrates, minimally, at idle. It's not a miss, just the vibration of the engine. I asked my SA about it and his reply to run a tank of gas with BG fuel system cleaner. Although highly skeptical, I did it and sure enough the level of vibration improved, but didn't disappear. While the mounts could be an issue, it's not bad enough to have them replaced

Thanks all for the advices.

I think I will first try some DIY without sending the car to a mechanic. The engine cleaning agent sounds easy, will definitely give it a try. I am also thinking of replacing the engine air filter myself. That should not be difficult. If there is any other DIY things that can help, I am very happy to hear it.

Again, thank you for the help!

I know im reviving an old thread....my 2015 XJ is having the same issue as well. took it to a shop and they said the mounts seemed fine. Ordered some Techron and will run a bottle of that to see if things smooth out