it has been extremely cold here in london ontario lately and have found that on these very very cold nights and or days. That my car sounds like a diesel engine inside my car. I can warm it up for 5 mins or 30 mins and it still makes that loud sound??? But once I drive a block or so, that sound and vibration disappears and sounds like nothing was even wrong??? What could be the problem??? Do I need new spark plugs or something??? To me it sounds like one or more spark plugs and working and or there is no oil or something??? Please help...

 

Sorry, at the end of my message I meant that, it sounds like one or more spark plugs ain't working as well as it sounds like I have no oil in my engine...

 

I've been having the same issue in the last couple days. It seems to only happen when the cars been sitting in extremely cold weather.

This isn't my video here, but this is exactly what my car sounds like on a cold start.
http://s431.photobucket.com/user/ple...short.mp4.html

I have taken it to the dealer, and they did a transmission flush and firmware upgrade, but the noise was back the next morning.

What could be causing this? Is it a serious issue?

Edit: I should mention that the sound is just barely audible from outside the vehicle, but very loud inside.