[Closed] STW mechanics, what would cause this?

head gasket gone.

We do see it on motorbikes laid up over winter at times, but not on cars in regular use.

Yep.

Condensation forming on the underside of the filler cap due to long periods of inactivity, turns the water and oil present into an emulsion that appears to look like mayonnaise; is another possible cause.

Head gasket failure would manifest itself as loss of power and considerable smoke out of the exhaust coupled with significant water use. Now I'm not saying your head gasket hasn't gone, but which of the above sounds / feels like it's happening?

If it's short trips you do it's normal.

Those 8v ohc units are really awful for it.

Its condensation in the oil.

I presume it's not using loads of coolant.

Is it just used for short trips, or does it regularly get a decent long trip to warm everything up properly? If it only does short trips, the oil may not get hot enough to clear out all the condensation that forms when the engine cools down. Then the oil turns to mayo.

As above, don't panic. It is classic HG, but it can also be caused by condensation from breathers. My car does it really badly as it's left laid up for ages.

Is the car in regular use?
If keep an eye on it, and be tempted to dump the oil and take a look at the condition of it. See if it contains significant amounts of water.

Depending on the car, some have water/oil coolers that can rupture and cause both to mix as well.

It's not like IT to go to defcon panic

As above . Wipe it off,check periodically. Get your engine good and warm regularly and change oil on schedule keep the moisture in your oil at bay

If it's not using water at an alarming rate , blowing smoke /steam out its arse / using lots of oil or mixing fluids.....don't worry.

I'm with the not headgasket crowd, unless the coolant water is filthy with oil or used up in significant quantities, (the exact symptoms vary depending on failure mode). I used to oil change my missis's Fiesta which never got a decent long run and it always looked like that, and worse.

Probably short trips and cold engine leading to the oil staying "wet" and never drying out properly.  Is the thermostat jammed open, does the engine warm up properly?

Or its head gasket, but I'd expect filthy or low coolant/boiling over and loss of power.

Any update?

I’ve had exactly this on an AIR cooled motorbike, caused by short runs and long periods sitting about.
It would disappear after a good long run.

I'm with the 'probably ok' crowd, its a rubbish indicator for buying as the seller can wipe it off, and I had a Punto I was quite looking forward to pulling the head off until I realised it was just condensation in the oil.

Yay, free mayonaise!?!

Sorry, been a hectic and stressful few days. Lots of worries on my mind on top of this.

Engine light now comes on intermittently, it is blowing out smoke, its using a considerable amount of oil and the water is very murky. There has been also a burning smell every now and again over the past few weeks which comes and goes, not sure if it's related or not.

The car in the main is being used for shortish journeys and can sit there for a few days without moving. But after initially finding the mayo, I have been to stevenage and back to see Lyanda's family so had had a decent run and a few longer journeys since and it's definitely gotten worse.

The power steering is playing up too, sometimes doesn't work at all and is generally very notchy. Fluid level is good, tried bleeding it several times but still the same.

As gutting as all this is, I think the cost to sort it all out is going to be quite high and not sure if it will be economical to do, especially with the mot in a few weeks and not knowing what else they might find.

Notchy steering is the rack dying - had the same in my XC90.
Def sounds like a blown head gasket.
I think your last paragraph may be spot on I'm afraid.
Amazingly, these two items might not stop it passing an MOT though.

Gotten worse? Are you in America?

EML and power steering fault will likely both fail MOT if they occur during the test.

Outside chance of an emissions test failure too, depending on the composition of the smoke...

I was quite looking forward to pulling the head off

Lucky Punto 🙂

Ah yes, with all the other symptoms that does sound like a head gasket. The 'smoke' is likely steam from water going through the combustion chambers.

Head gasket and power steering rack is going to cost upwards of £1000 I'd have thought. Reconditioned power steering racks aren't dead cheap, and neither is a particularly quick job. 🙁

power steering fault will likely both fail MOT if they occur during the test.

Oh right. My XC90 (which had a very notchy steering rack when cold) passed a couple of MOTs before I changed it for one from a scrappy - maybe different rules ??

There have been a fair amount of rule changes since I last mot'd a car.

8v Astra G? They do tend to overcool on short trips and mayo up. However yours sounds worse.
Random power steering failure can be the alternator on those (electric PAS), check the connections on the alternator.
There's a pedal combo you can do to give a series of flashes to show what possible fault is throwing a light. A quick Google will find it

Edit, ignore the pas bit, you mentioned fluid.