Possible blown head gasket?

[Gjk]

Took the esprit out for a data log run this morning and when I got back I was greeted with this….

steam from coolant leaking onto the exhaust manifold from cylinder number 4 area (approx).

There was no steam from the exhaust though.

[drdoom]

Pull the plugs for an inspection of cylinders, get a borescope if possible. What's the state of things in the coolant reserve tank? 

[Gjk]

Coolant tank (next to chargecooler one) was low but no oil in it.

going to do a compression check tomorrow 

[jonwat]

5 hours ago, Gjk said:

going to do a compression check tomorrow 

You can also test the coolant for exhaust gas with a tester kit 

[Gjk]

Turns out not to be head gasket at all! Topped up the coolant this morning only to find a puddle appearing on the ground and the faint sound of trickling water. Looked under the car to find….

the core plug in the cylinder head has a small hole in it.

[drdoom]

Ahh, I'd hoped it was that. Minor thing in terms of knock-on consequences, unfortunately requiring removal of the lump for a proper fix.

[Gjk]

Core plug replaced. All sorted.