Any ideas out there?

I handed my beloved 2002 A4 sport 1800 turbo to my son in law a few years back and about 12 months ago he tells me the engine sounded rough and his local garage said it needed a new engine.

I told the garage that it had suffered a blocked oil filter pick up strainer gauze some years back, so they checked that and once it was cleaned out the rattling tappets stopped and no doubt the noise was due to low oil pressure due to the pick up strainer being blocked.......no new engine needed after all!!

Around 6 months back the engine is sounding rough again (but different this time) and the same garage see a load of water in the oil and advise a new head gasket and a big bill. I am aware that head gasket issues are unusual on the A4 and I find that the water has not needed topping up in over a year. So the water is unlikely to have come from the cooling system.

I then learnt that my son in law had been topping the oil up regularly on the basis of the oil level light coming on, and he had never actually checked the dipstick (which is coincidentally what I started calling him).

So he changed garage to an Audi specialist I trust looked into the issues and sure enough the oil level was very high but there were literally pints of water sitting on top of the oil. The mechanic drained the huge quantity of oil, flushed everything out several times filled with new oil and the engine is running sweet again. Next morning he starts the car and the smoke covered most of the village. 10 minutes later and the engine is sweet and smoke free again. So he is a bit baffled where the water has come from, and why the engine ran well and then started so smokey. All is well that ends well we think so we pay the bill and the car runs great again.

Now if the coolant system isnt being topped up then where is the water coming from? A rainwater leak? Hardly likely!! Condensation from the combustion process?

Well the engine has around 150,000 miles on it and is presently doing very short journeys of around 4 miles to the station in the morning and 4 miles on the way back. So this could certainly be generating the condensation. But shouldnt the engine breather system be sucking most of this moisture vapour away? The garage looked into the breathers, although I have no idea how thoroughly. I was wondering whether the oil level being too high had somehow blocked off a breather and therefore allowed the condensation and water level to build up.

So the car ran well for 4 months since the drain down and flush and last week the same problem appear to have cropped up. The engine sounds rough and there is a lot of water and white emulsion on the dipstick. No water has been lost from the coolant system but the oil isnt being topped up when the level sensor warns low oil.

We are sure that the oil level sensor is faulty, so oil top ups only happen after reading the dipstick.

So is this likely to be a blocked breather?
How easily do they get blocked?
Do they have metal gauze filters that are likely to get clogged with water / oil emulsion?
How many breathers may be involved here?
Is it likely that the blocked oil pick up pipe suffered a couple of times may also be related to the same problem of emulsion being generated?

Has anyone out there similar experiences?

Thanks

John