small steering wheel vibration when idle

[mig0s]

Hey guys, since the beginning of November, I've noticed that there's a small vibration on the steering wheel when i'm idle. When the car starts to move, the vibration goes away. I've never had this before... what could it be?

Notices:
-In the month of November, it turned really cold. Sometimes below freezing point but it only snowed twice.
-I changed my tires from 215/40/18 to 225/45/18. But the small vibration comes when idling... so idk.

Thanks.

[02slera]

time for a tune up?
if my car did that id replace spark plugs and wires, mainly because i need to do it anyway, i dont know if they've ever been changed on my car. maybe some more info about your car would help others help you, such as mileage, if/when you spark plugs were replaced, what rpm are you idling.

[mig0s]

Well I've replaced 4 months ago my 6 spark plugs (NGK platinum) with brand new spark plug wires (NGK). Synthetic oil since I bought the car in april, changed transmission oil (red line). Just haven't flushed my coolant yet. So I don't think it's the tune up. My car has 105k miles... The vibration is really low, but it doesn't do that before...