I found the web article...
This is the problem...
In the 8-cylinder engine a metal coolant pipe connects the water pump to the rear engine coolant passages. The pipe is sealed to the engine crankcase using rubber O-rings. These O-rings fail over time, causing a coolant leak in the valley of the engine. This coolant leak usually appears on the ground, at the rear of the engine in the transmission bell housing area. The pipe is tucked away under a valley pan that lives under the intake manifold.
There are a few repair options for when the pipe O-rings fail. You can use a BMW factory part, but this requires removing the front timing cover, including the timing chains and front end of the vehicle. This method can take a few days to complete.
A few aftermarket companies developed a way to repair the pipe without removing the timing cover housings. You cut the pipe out of the valley, then install an expanding pipe into the engine and secure the O-rings and pipe in place with pressure from the expanding pipe.
This Link takes you to the web page where the sorry and expensive solution is explained.
On an Aero it will be wings and cowl off, I guess.
