Driving a Renault matter down the motorway heading for two weeks of social distancing and the oil light comes on. We pull over and pop the bonnet and there is oil everywhere and accept in the engine. We get towed a n a the mechanic fill so it up with oil and starts it and can only find a tiny leak from the breather valve on top of the crankcase. He pushed it down and it makes a clicking sound and we think we have an easy solution. We wipe it down and leave a clean rag on it for a short test-drive and after one more check for no leaks we get back on the motorway. We pull in for deisel and check the engine and were down to almost empty with oil sprayed everywhere again. I put oil in it today and it ran fine, we cleaned as much as we could and got it up on tracks to check the bottom and can't find a leak anywhere. Engine runs great, good power.... Any ideas on things to check or how to work on the breather valve would be appreciated. or other explanations for a massive oil leak that doesn to show itself except at high speeds Im not a mechanic but have tools and it's been hard to get a shop to look at in because of the virus.