Why does my BMW X1's engine make a noise on cold start?

I've noticed that when I start my BMW X1 on a cold morning, the engine makes a rattling noise for a few seconds before running smoothly. Is this normal, and if not, what could be causing it? Should I be concerned?

The rattling noise on cold start is quite common for BMW X1. It's usually caused by the hydraulic lifters adjusting to the temperature change. As long as the noise goes away after a few seconds, it's nothing to worry about.

If the rattling noise persists for more than a few seconds, it could be a sign of low oil pressure or dirty engine oil. It's always a good idea to have your car checked by a mechanic just to be safe.

I have the same issue with my BMW X1. I found that using a high-quality synthetic oil reduced the noise significantly. Give it a try and see if it helps.