rough idle on startup
 

some mornings before i leave for work, when i start the engine up and leave it running it begins to shake quite violently. i then proceed to turn the car off and restart it again to find that it has gone away, or if this does not work, i just drive for a bit and the shaking goes away. any insight into what could be wrong? thanks in advance

anything and everything could be wrong, what kind of car is this?

03 x5 3.0. is it true you can go to autozone and get a free scan done to see what the error code is? the "service engine soon" icon shows up when it starts shaking

yes very true. multiple misfires on cold starts ups can be a variety of things. check the faults first.

Easiest and cheapest things to do would be

1. Run a bottle of fuel system cleaner. I'd recommend Redline SI-1.
2. Clean your MAF sensor
3. "Dust out" your air filter
4. Remove and clean your ICV. While you do this - check for a tear in the boot that connects the air intake to the ICV.

sounds like a vacuum leak

Had this happen twice on the last X5 many years ago. First time, ignition coil. Second time, thermostat.

See other threads on X5 shuddering in cold weather - I have an '04 4.4 that was having rough starts as well on cold mornings along with the SES lamp. After 3 service calls to BMW they indicated the lift levers needed replacing (a TSB is out for this issue). It was a 2 day job to replace them and all covered by the CPO warranty.

But the intermediate levers won't be a problem for an 03 3.0i, he don't have them. :D

Get the codes read and tell us what you got.