Originally Posted by Dave Henshall

mayo in just the breather can be a sympton of lots of short stop/start runs - my old pug 19git used to clog up when i lived only 3miles from work, once a good run up the motorway it would all be clear - the oil mist mixes with the cold damp air and emulsifies, if it never gets hot enough to make it runny and burn(digest) it off it just stays in there looking minging - a quick and easy check it to take it to a MOT station and askj them to put the emmisions probe in the actual headre tank - it will show if any combustion products are being forced into the cooling system.