2001 BMW X5 3.0i - Soft-Roading on the Cheap

[Jake]

The 911 does that throttle thing under load, almost always when in second gear. I've had it to three different shops, including an old Porsche guy who could diagnose most problems over the phone, and no luck determining the cause.

Interesting, especially given you're with a manual trans and throttle cable. This is drive by wire which adds a layer of complexity. 

If nothing else, the trans fluid check is good for my peace of mind.