04 X5 4.4 98K BAD COLD STARTS

[manfrmbklyn23]

First off my car has bad valve stem seals, so it lets off white smoke if idles for too long.

New problem. When I start the car after it has sat all night and it is below 20 degrees, the car starts very rough! loud and the engine makes the whole car shake back and forth. It literally sounds scary to my kids and dangerous. Also the check engine light comes on and blinks for a minute or two. sometimes the CEL stays on for a while or turns off before I pull off. After 5 minutes or so the car is fine and drives great. Any direction or help as to what it can be would be great thanks!