Head Gasket or Condensation problem?

Lightning Coupé

Senior Member
I doubt the problem has anything to do with which type of oil you use. Condensation occurs when warm moist air comes into contact with a cold surface, the cold surface cools the air quickly, making it denser, at which point any water saturated in that air drops out and is deposited on the cold surface. That’s the way de-humidifiers work. For example when you breathe warm moist air on a cold glass window it mists over with condensation.

When an engine cools, it will do so from the surface inwards toward the core, and so the rocker cover, made from aluminum which has excellent thermal conduction properties will probably cool faster than the air inside the rocker box which is kept warm by the engine core. At this point any moisture in the warm air will drop out and deposit on the oil splashed rocker cover to give you the milky white substance you’ve witnessed.

When you go a good distance in your car, the air and any residual water within the engine will become dryer to an extent as the water evaporates off and is lost through the breathers (hence they can get full of gunk). Lots of short journeys and you never get rid of the moisture in this way. So the best thing you can do is just give the engine a regular oil change. For the sake of £15 or so for the oil and filter and the 5 mins it takes, do it once every 3 months to be on the safe side and I suspect your engine will not suffer for all the moisture in it.

Alternativly, You could try a plastic rocker cover from a scrap yard and see if it helps?
 

Mark Dj

Former Staff
Senior Member
Thaks for that mate :). I will keep a good eye on my oil then for now. I will try and do long trips on my days off :D . Cheers
 

abz2005

Member
i know this is an old subject but.....im having the same problem, i had an oil change just over a week ago and as mark dj said this has only happened since the oil change....lets hope its condensation
 

rushy

Senior Member
abz2005 said:
i know this is an old subject but.....im having the same problem, i had an oil change just over a week ago and as mark dj said this has only happened since the oil change....lets hope its condensation
Happened to mine just after a service, after about 100-200 miles it cleared itself up.
 

Rick201i

Regular Member
I've got condensation on my oil cap .when it's warm weather it's not there.at the moment I only drive 5 miles each way to work that's it
 
Top