While over at the brother in laws house yesterday he mentioned how his Girlfriends Mk3 Golf had a squeeling fan belt. Had a quick look and noticed all the oil leakign out the rocker cover gasket. Mentioned it must use a lot and he said it also uses lots of water...... Oil filler cap off and lots of dread mayo! Guess what I am doing next weekend!

Two questions really - has anyone done the head gasket on the VW 1.4 ABD engine - anything to watch out for?
Second one is I am hoping the mayo isn't too bad but what is the best way of cleaning it out? There is nothing on the dip stick only on the filler cap.

Head gasket problems aren't that common on those IME. Mayo on the filler cap is on cars doing lots of short trips and is usually due to not getting to oil hot enough to evaporate condensation build up. If there's no sign in the sump it's more likely to be that than the gasket. Look elsewhere for the water loss first to rule out a separate leak.

To many cold runs, if it was the head gasket it would be using coolant. An engine produces something like 40 gallons of water for every gallon of fuel burnt, some of that ends up in the sump and unless the engine is running hot enough to turn it to vapour it stays in the oil system.
Check the thermostat is working and the fan isn't cutting in too early.

It is using coolant BT.

Check the thermostat, they have a habit of self distracting , also check for staining around the water pump,if doing the head gasket it's worth fitting a new timing belt kit and water pump while your at it. Water pump impeller failure is common on VWs Probably worth checking the breather system as we'll