A31 Coolant Return Line Variation

[rayj]

Hey

I've noticed there is a variation in the stock coolant return line for the A31 turbo.

Normally is just one long line running behind the engine connecting to a hose.

In the FAST diagram below there is a variation in the bottom left box.

The coolant return line has a nipple towards the end of the line behind the engine, where it splits off to another hose.

Where is it meant to connect to?

You can also see this in my turbo photo below.

Thanks