[wallyman424]

Originally Posted by technician117

This is incorrect. The DME's and intercoolers are on their own separate system that runs at a lower temperature than the engine and turbos. It's true that the turbos have a cooling circuit, but it's run from the same system and reservoir as the main engine. The confusion comes because the turbo coolant system is run by an electric pump after the engine shuts down. People think this is a separate system but it's actually drawing engine coolant to run it. I just reviewed the technical data so please don't argue.

The S63TU technical data document is posted on this website, I don't have the link handy (I have the document on my computer now). They actually do a good job with pictures and diagrams separating out the different systems.

Summary:
DME's and intercoolers have their own (2) electric waterpumps and a reservoir in the middle/top of the engine. This system does not utilize a low coolant sensor in the reservoir, but the pumps will shut down and store a code and display a message if they sense they are pumping air.

The engine and turbos run from a separate system utilizing a mechanical pump AND electric pump (to continue cooling the turbos after shutdown). They run off of the reservoir located near the firewall. This tank does have a coolant level sensor.

That is interesting.