When timing guides in a 4.6 become a problem is a guess. It might be around 100,000 miles, it could be at 25,000 even 50,000 more.

The 4.8 is better known for valve guide failure after 75,000 miles but could be fine at 150,000.

BMW issued a warning on the 4.4 engine timing guides in 2008 but the 2007s aren't known for timing guide failure.

When you are looking at vehicles that are 10 or more years old all you can do is seek out one with a great history, few owners, clean carfax, great PPI results and most of all what you like most and drive on. Even what sounds like the best there is may end up being the worst. Ya pay your money and take your chances. When you love what you bought problems are easier to stomach.

__________________
X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas