no, it has a chain
Nope.
yes
M52 engine has a cam chain, no cambelt
No the camshafts are chain driven.
I would say within 100,000 miles.
Yes
it has a cam chain
The 2004 BMW M3 has 24 valves.
The 2004 BMW X3 has 24 valves.
The 2004 BMW X5 has 24 valves.
The 2004 BMW Z4 has 24 valves.