Go forth and emulsify

I have been looking at Hyundai Coupes around 2005 model 2 litre engine. Every car I have looked at has cream inside the oil filler cap. Is this normal? I was told many years ago never to buy a second hand car with this problem as it was an indication of a failing head gasket. You advice will be very much appreciated.

Asked on 19 September 2011 by KB, via email

Answered by Honest John
Could be. Emulsified oil ‘mayonnaise’ can also be an indication that the car hasn't been used for a long time, or that it has been started from cold a few times just to move it and not been allowed to warm up properly.
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