Coolant issue...last leg of jspec swap. (S5 na to S5 Jspec)
 

So im putting everything back together, finishing the jspec swap. Reinstalled the radiator, started pouring coolant into the thermostat area, after about a gallon, I notice coolant dripping on the drivers side.

Upon looking, it appears to be leaking from the top half of the rear rotor housing on both sides of the housing. About where the oil dipstick goes for reference of how far up the side of the engine.

The passengers side i cant see much, but the leak is collecting and dripping from the heatshield of the turbo. The front of the car is on jackstands. Ive already checked the coolant drain plug, its snug.

Anyone have any ideas? The car hasnt been started yet, and when buying the motor i checked the leading plugs on both housings, no signs of rust filled coolant or coolant in general. Any ideas?

I'm not sure exactly how the hose routes on a turbo engine, but at the top there should be a coolant hose to the throttle body that warms the thermowax (for the high idle cold start). I don't know if you retained this system or deleted in the process of the swap, but it is possible that the hose is old and leaky.

Possibly..But why would it be leaking from the sides of the motor, most.visable one being midway up the engine on the drivers side at the seam where the rotor housing bolts up? On an unpressurized system? This is happening with me just pouring coolant into the thermostat housing.

Are you saying it's coming from between the housing and the iron? Or that it's pouring down at that point? If it's coming from between the housing and iron, maybe the outer coolant seal is broken. It is rare, but not impossible.

Can you post a picture?

I'll snap a photo of it tomorrow. It appeared to be leaking out of where the rear housing meets the iron midway up the engine.

Funny thing is though, the left side was leaking too. I couldn't see where it was leaking from on that side, but it was trickling down off the turbo heat shield on that side.

If the coolant is in fact leaking from between the housing and the iron, then I'm pretty sure you'll need a rebuild. The only way I can see for coolant to leak from the seam between housing and iron is either the outer coolant seal broke, or the engine underwent such stress and heat that the iron or housing cracked and is seeping coolant.

Hopefully it is just dropping down from somewhere else up on top of the engine.

It looked like it was coming exactly from where the rear rotor and iron meet (left side of rear rotor housing midway up on drivers side.)

But what gets me is, it was leaking on both sides. The drivers side way more than the passengers,
and the coolant system wasn't even pressurized at all.

You would think if it is an outer seal or crack, it wouldn't leak like that with no pressure in the system right? I couldn't see a crack either. Ill snap a picture tomorrow.

I agree it would be pretty strange for both sides to leak. And unpressurized, at that. But I can't think of any other way for the block to leak like that.

I think the possibility that the leak is coming from the thermowax/BAC circuit was dismissed too soon and deserves investigation.
In fact, looking into that first will only require disassembly you'll have to do anyway, so you're no worse off.
As a NA guy, I'm not familiar with your manifold arrangement but you'll need to strip back enough to expose the outlet at the rear of the water pump housing and the return at the top of the block. Remove the hoses and make sure the metal bungs aren't rotted beneath the rubber and if not, use some spare hose to connect the two ports together directly.
Remove the belt and you can spin the water pump directly with a power drill (or whatever) and see what happens. You'll have full flow through the engine with no flooding or battery drain issues and it should be fairly easy to find your leak.

pictures speak a thousand words.

You talk to pictures.