Hyundai Matrix 2005, Car startup vibrate heavyly, light indicator blink.
Cat startup vibrate heavyly, light indicator blink. after around 30 seconds car no more vibrate, the light also close, off.
anyone know what issue is causing it, is it still safe to drive the car?
You could have a couple of problems, first thing that I can think of is you have either a head gasket leaking coolant into a cylinder, a cracked cylinder head, leaking injector causing a cylinder to be flooded out for a few seconds after setting overnight. Having the codes checked could help with diagnosis. I would only drive it if you have too. If it is a head problem you could damage converters, O2 sensors. Get it checked as soon as you can.