Car Shaking This Morning: Check Engine Light

[Aimster]

Car had been sitting for 4 days in the freezing cold. I started it this morning and it was shaking like crazy. After 15 seconds the check engine light came on. I didn't drive it. Took the other car

I am worried. 2 weeks ago I put coolant in the car. I got 100% coolant and added water to the other 50%. I have been doing this for years. I don't think this is the problem though. It was much much colder last week and the car was operating normally. I checked the top of the coolant just to make sure and it wasn't frozen.

Ahh every week something is wrong with my X5. I hate it. Guess that's what happens with old cars.