Coldaslife

I have a coolant leak under the intake manifold on my 2006 audi a8 4.2, need some advice to know what is wrong before removing the entire intake manifold please.

Jack88

Get a cheap borescope with a light on it and start poking around. Remember, the highest point you see evidence of coolant is your likely leak. There are a few possibilities at the back of the motor. I hope you don't have the dreaded oil cooler leak, that would manifest just below the manifold on the forward end of the block, passenger side(US). Generally you find coolant on the belly pan, alternator wiring and the oil pan, but the actual leak can't really be seen.

Coldaslife

The coolant is only leaking under the intake manifold, i can see a few drops at the back of the engine when the car is on the lift. No drops at the front and the sides are dry too.

Sci-fi_Wasabi

look at my thread here:
https://www.audiworld.com/forums/a8-...hange-2842064/

there is a very weak part in back of the manifold that coolant runs through... weak plastic part that crumbles after enough years of heat soaking. There is a port at the top and one at the bottom that may be harder to see. The leak leaves residue along the back of the engine as you described. Your 2006's setup may be a little different than my 2009 because of the FSI engine change.