whats causing sludge?

head gasket is blown

m
June 2009

Running about the town ,short journeys may be the problem, try an oil change after flushing the engine with proper flushing agent, hope this helps.

Alistair Phillips
May 2009

This is an oil emulsion called 'mayonnaise' in the trade....its formed as water vapour condenses inside your engine, especially if you only use the car for short runs, when the temperature doesn't get hot enough for this water vapour to be dispersed. Changing the oil helps a bit, as does wiping as much of the stuff away as you can with a rag. All petrol cars do it to some degree.

John
May 2009