Hi All

I have a lovely 2012 Artic White 4.4TDV8 Vogue SE - which I love to bits!

For 6mnths now I have been hunting a large oil leak which also presents as smoke (a lot) under boost while driving, followed by a lot of oil on the top of the engine tappet covers and down the front of the engine (and on the ground when I stop). I replaced the usual suspects - oil cooler rubber gaskets from Land Rover, Viton o-rings on the pipe on the back, new thermostat for good measure (240 000kms on her) Still the same.

I did notice that if I drive very softly (boost wise, not revs) that there is no oil leak - Also that if I wait for about 20mins after starting to drive, boost does not result in any leaks. No limp mode codes, no reduced performance, nothing.

This weekend I did a test - I connected a boost gauge to the oil extraction pipe to measure if any intake boost is ending up in the crankcase, and ....... YEP, when she's cold, even small boost (0.2 bar) will show up on this gauge. full boost (1.5ish very quickly) resulting in oil being pushed passed the rubber seals. Curiously this seems to stop when the car is warmer. This leads me to believe that the crankcase ventilation oil separator may be sticky, letting boost in from the intake manifold to the crankcase, and then sealing when warmer.

Has anybody seen anything like this? I would not like to strip all the way down there just for fun....

Do you have to strip the entire oil cooler assembly out to get this replaced? or is it serviceable?

I see there is a +- 20mm rubber pipe connected to what I assume to be a plastic breather pipe going down into the engine right next to the oil cooler. It seems to be held in place with 4 bolts. Is this a top portion of the PCV assembly that can be removed and cleaned?

Any guidance will be greatly appreciated.