Went to start the car this morning after packing the family and bike.

Low coolant level light came on. I looked in the tank and it was low and very dirty. I took a sample which you’ll see below against fresh coolant.

I then checked the oil level and it had gone up and looked minging compared to last weeks oil check.

Car is a 2011 Mercedes C220 cdi with the common as muck 2.1 turbo diesel. 108k on the clock. Oil was fine last week.

Head gasket failure non?

Yours depressingly.

Could be but many cars have other places where oil and water get close to each other such as heat exchangers etc.

Sniff test the coolant header tank to confirm head gasket failure.

Certainly looks like head gasket failure and the water is pressurising the oil

Could be, is there “mayonnaise” under the oil filler cap?
Alternatively it could be a failed water pump seal, as it was on my Skoda (a much cheaper fix than head gasket, so hope it’s that in this case!).

Bloody hell.

Before I get too technical – given how there’s not much I can do on a Sunday – any further experince on how to approach the dealer?

I bought the car in October, so 3 months ago, therefore it’s covered under The Consumer Rights Act 2015.

I live 60 miles away, clearly can’t drive it and it came with an RAC warranty which really means naff all, but the The Consumer Rights Act 2015 does!

What would be your approach? Of course I’m going to contact the dealer tomorrow and I’m sure they’ll simply tell me to take it to a VAT registered garage. I’d rather the fix became their immediate problem or, preferably, get my money back.

Anyone been through something similar recently?

No mayonnaise, i think it’s happened very recently.

Read your warranty to make sure you’re covered then see what it says about making a claim.

That certainly looks like oil in your coolant.
Not necessarily head gasket, it could be egr valve or oil cooler.
Whichever it is, it needs fixing immediately – take straight to your garage.
That engine isn’t known for blowing head gaskets, you’ve been unlucky if that’s what it is.