2007 X5 4.8i starting issue
 

When I get in my car after having let it sit for 24 hours and start it, the start sounds labored. If I stop the car and start it again, it sounds fine.

It's been going on now for about 3 years. I replaced the battery back then thinking it was the battery, but it didn't change.

Lately I've been wondering if it's because my valve steam seals are leaking and there is oil in the cylinders which is hard for the starter to overcome. Is that a possible cause?

My valve steam smoking/leak isn't bad like I see in videos on the web, but i can't definitely see/smell it if I have extended idle and then punch the gas. I"m at 127k miles.

Here is what back to back starts sound like.

https://photos.google.com/photo/AF1Q..._wR3x_qoJLMbd4

Looks like the battery was just tired. It had less than 4 years on it, less than 40k miles but nearing the end of life. It would charge up to 12.2 with the alternator, but the next morning I'd see 11.2-11.4 on it. Replaced it and starting much better again, still every now and then it sounds like it struggles a bit but WAY better than in the video.