Aygo - Oil filler cap with yellow/brown sludge...

[Andy 308GTB]

Daughter's 2018 Toyota Aygo. 15,000 miles on the clock.
I've read about this but never actually come across it when working on the home 'fleet'. Head Gasket failure is the typical answer on the interweb.
Thoughts?

[steveo3002]

is the coolant dropping?

a small amount of mayo isnt uncommon on cars that only do local trips

[InitialDave]

steveo3002 said:

a small amount of mayo isnt uncommon on cars that only do local trips

This would be my first guess before assuming the worst.

[Andy 308GTB]

steveo3002 said:

is the coolant dropping?

a small amount of mayo isnt uncommon on cars that only do local trips

I did have to top up the coolant a little bit.
Yes, it does daily small journeys interspersed with the odd 180 mile trip.

But we've had the car since new and it's done the same pattern of journeys for nearly 3 years and this is the first time I've found this.
I guess all I can do is keep an eye on it.

Thanks both!

[MB140]

If it’s only ever used for short journeys in cold weather then this can be quite common a side effect and doesn’t necessarily mean head gasket failure.

Clean it up and take it out for a spin assuming it’s running okay. Check coolant level before doing this. Check on return.

[steveo3002]

keep an eye on it for now , would be rare for a head gasket to go so early

but if the coolant is dropping ,its going somewhere

[GreenV8S]

Water in the oil is perfectly normal and no cause for concern.

Coolant level dropping is not normal and indicates a problem.

Oil or combustion products in the coolant is not normal and indicates a problem. A block test aka sniff test is a good way to detect that, but if you see scum in the header tank that's a pretty strong sign.

[keeling54]

If you are really worried drop the oil and check it. Then give the car a long run to get it warm and check the cap again.

[Twig62]

Get the oil and filter changed then try and make sure that it gets a good run once a week.

[Peanut Gallery]

Mate has a Toyota Iq, the oil filler is on a short swan neck out the side of the head, and as such never really warms up. There is always a small amount of mayo in the cap, even after one drive from London to Aberdeen in one day. (550 miles, yes, he had tinnitus)

In short, if yours is off the side of the head, I would not worry about it!

[C5_Steve]

I'd go with all the comments around this being normal. My sister recently bought a newer Clio that was only used for short trips in cold weather and it looked exactly like this. It's caused by condensation rather than coolant, clean it off and check again in a few days.

[Hol]

My sons 2009 1.0 Aygo used to do this many years ago as he was only doing short journeys to college and back. It stopped when he moved to uni and it had a few five hour commutes to get it going and it even survived a 200mile non stop journey back from Wales with diesel polluted fuel in it. Although that did fk up the cat converter.



If you are really concerned take it to a garage for a sniffer test to see if there are any hydrocarbons in the water.

[Andy 308GTB]

Thanks all.
The car was only with me for the weekend, as my daughter has now returned to University. I'll run through this thread again when she returns at Easter.