Over the winter I've developed a small coolant leak that I've yet to track down. The puddle is a couple table spoons worth of fluid that takes a day of sitting before appearing. It shows directly under the downpipe. I can actually see the fluid collecting in top of the downpipe end flange before it drops to the ground.

The turbo and thermostat housing appear dry upon quick inspection. It's as if its running down behind the downpipe heat shield.

Ideas?

 

This is what my leak looked like when the thermostat housing had cracked and needed to be replaced (for the second time). I guess it's possible it could be leaking from the coolant pipes on the turbo. The top one is easy to see. I would suspect a thermostat leak before just about anything else though.

 

Damn that's dead on for mine. I shall start there then.

 

Also the oil cooler/heat exchanger assembly is a known leak spot, more likely to see oil coming out of there though. Mine failed and was dropping oil onto the down pipe and gave a slightly oily smell. There is also an auxiliary water pump tucked behind there to cool the turbo when the car is off, so be sure to check that too. There is a LOT going on in that area and coolant and oil going every which way in a super hot environment. Big surprise anything rubber in there fails...

 

It was this. The triangular gasket responsible for the coolant loop was torn and smashed. Talk about a PITA.