my astra not running right, had a look in my oil filler cap, was all cream, and car keeps missing, when driving, lack of power, any help would be good.

chris, March 2009

This is typical of the mk3 astra 1.6 8v. Its down to the fact the top stays cooler than the bottom which causes condensation hence the mayo. Its nothing to worry about but make sure oil is changed and use oil cleaner then replace with fresh oil as it can clog up pipes.

Im an owner of this car and have worried about it but theres nothing to worry about.

Joshua, April 2013

This may be as a result of a leaky oil filler cap, which allows condensation into the rocker cover which then gets emulsified with the oil. This normally wouldn't be a problem, but the engine management system (EMS), in order to reduce emissions, takes air from above the rocker cover. If the space is full of oil and water emulsion, this will be drawn into the air intake, and the plugs will become oiled and misfire. In my model (2001) it also resulted in the EMS showing up a light on the dash, solid when not under load but flashing when accelerating. You need to clean out under the rocker, get a new set of plugs and at some point a new oil filler cap. Thanks to Darsham Tyres, Suffolk, UK for sorting this out. I thought it was a cylinder head as well.

Pete Rowberry, May 2009

i can only agree with George (Boroboy) but i would suggest to do ya every day checks like =
water (level is where it should be & to make sure that mayo stuff dont turn up in there,that would suggest headgasket but if its clear i doubt it very much).
check that your not loosing oil make sure the oil level is where it should be,etc

micheal (mikall), March 2009

Mayo under oil cap common with Astra 1.6 8v's (I own one). Don't worry about it, caused by short journeys. If your temp gauge gets up to heat (half way) on temp gauge. Then all ok. If temp stays cold all the time. You'll need new thermostat. Have to take cambelt off to change it. Good time to change cambelt kit.
If not loosing coolant, then won't be HG. Try changing your plugs first. If not plugs,, then 9/10 coil pack. Buy one from breakers for around £25 (off car). Easy diy change, need to take battery off to gain access. Coil pack held on with torx heads.
This forum will help you:- http://www.vauxhallownersnetwork.co.uk/forumdisplay.php?f=83

George (Boroboy), March 2009

Sounds like the head gasket leaking. But don't take my word for it wait for more replies

Bob, March 2009