I have a 2018 1.5 TDCI and its started dripping coolant from behind the DPF, only noticed tonight just before it started getting dark.  I started to strip the engine bay out tonight but its going to take me hours tomorrow to get close to the leak.

Anyway, Ive found a pic of the same model engine with the DPF removed just so I can see what there is behind there that may be leaking.

From the underside it looked like it might be the red banjo, but now seeing this, that's obviously a oilway. So I can only assume its the oil cooler leaking. Now, is this common? I can see you can buy the replacement oil cooler element (circled in blue) , OR the entire unit. Any experience of this leaking?

Any ideas are welcome

Thanks!

 

That looks like an EcoBlue oil cooler rather than a TDCI cooler.  Mk3 used TDCI, Mk4 used EcoBlue.  The parts aren't all compatible so you will need to know which engine you have.

The oil coolers don't leak often.  I've seen more where the oil has leaked into the coolant than where the coolant is leaking externally.  There are rubber gaskets inside which may have failed.  Though it would be unusual on a 6 year old car.  I'd be checking the pipes and thermostat housing above that area personally.

Managed to get to the oil cooler after about 8 hours, had to strip the DPF and Turbo to get decent access. turns out it was the gasket between the oil cooler/filter housing and the engine crankcase. coolant leak to the external luckily, so no contaminated oil.