2005 Vauxhall Astra engine

Vauxhalls are bad for that . It is usually just condensation rather than head gasket .If in doubt carry ouit a block test .

Just an aside , a family member had one a few years back and I could take oil cap off and lift out dollops with my finger .Was checked under warranty , but normal .As long as no water loss or pressurising of cooling system , should be o.k .Actually gets worse with cold weather and short journeys .

Regular oil/filter change with an engine flush will help.

" Regular oil/filter change with an engine flush will help.
"
Sorry to disagree and talking from experience it doesn't make an ounce of difference on that and Corsa's .It's an inherent fault .I have heard if you fit a plate over the front of engine to deflect the cold air passing over the engine works .Within days of oil and filter changes it starts again .

OK, thanks Whittingehame, I didn`t realise that. I just thought that keeping the engine `clean` with fresh oil would help.
So is it due to the engine running `cold` which then produces more condensation? hence more of a problem if used on short journeys?

I used to be a service manager with a GM /Vauxhall also and it was a nightmare trying to convince some customers it was normal after friends had told them it was head gasket gone .Briefly it's to do with the body design , airflow , cambox cover etc .and cold air meeting hot engine etc .etc .Fitting that plate alters and deflects the flow enough apparently to improve matters .It was another fleet manager who was fed up with the problem and told me that it worked , though I never tried it out .

Should have added that for every gallon of fuel ( cant remember the figures ) the engine produces so much water and if you do short journeys and the engine doesn't really get to working temp to get rid of most it ,wont help either .That and the breathing of the engine .

It get's a lot worse in the winter with the cold air and engines taking longer to warm up and reach operating temp , then improves in the summer .