Orange scum in coolant cap

Hoboo

Just got a service this week, no issues according to the garage, but today when I opened the coolant cap which has fresh coolant in, theres an orange scum and bubbles. Is this an issue or normal? Been serviced every 12 months by same Mazda main dealer since new, 65000 miles. Never a problem.

2014 Mazda CX-5 2.2 diesel.

Thanks

biko

You say "fresh coolant". Was coolant just topped up, or flushed and then filled with the 8.5 litres it needs?

It could be mixing incompatible coolant types.
It could be an issue with the head gasket (oil mixes in).
It could be something else.

I'd start with blaming the coolant, and draining out the current coolant, flushing with water and then filling with fully fresh coolant.

smuggler.ie

Would not like this, nor garage statement "all good"

Hoboo

biko wrote: »

You say "fresh coolant". Was coolant just topped up, or flushed and then filled with the 8.5 litres it needs?

It could be mixing incompatible coolant types.
It could be an issue with the head gasket (oil mixes in).
It could be something else.

I'd start with blaming the coolant, and draining out the current coolant, flushing with water and then filling with fully fresh coolant.

Grand thanks for your reply.

Just need not be able to go back tomorrow with any sort of knowledge. I'll ask them to do as you suggest. How long should I expect for the scum to return if it's gasket or something else, or is it just a case of keep checking and if it stays clean for a month it should be good?

Cheers.

Hoboo

biko wrote: »

You say "fresh coolant". Was coolant just topped up, or flushed and then filled with the 8.5 litres it needs?

It could be mixing incompatible coolant types.
It could be an issue with the head gasket (oil mixes in).
It could be something else.

I'd start with blaming the coolant, and draining out the current coolant, flushing with water and then filling with fully fresh coolant.

I honestly don't know if it was flushed or just topped up. Will ask that first before mentioning the issue. Thanks.

corks finest

smuggler.ie wrote: »

Would not like this, nor garage statement "all good"

Hopefully not a head gasket prob

Hoboo

So it's the head gasket. No milky residue in the coolant or oil, just the orange at the cap. CO2 test was positive, if that makes sense. Stripping it down to see what the cause is. Not overheating or any warning signs. Under warranty so no cost to me.

Next question. Is the engine good to go once it's flushed and new gasket, or am I looking at likely failure over the next few years due to leakage?

Thanks for any input.

corks finest

Hoboo wrote: »

So it's the head gasket. No milky residue in the coolant or oil, just the orange at the cap. CO2 test was positive, if that makes sense. Stripping it down to see what the cause is. Not overheating or any warning signs. Under warranty so no cost to me.

Next question. Is the engine good to go once it's flushed and new gasket, or am I looking at likely failure over the next few years due to leakage?

Thanks for any input.

TBH I'd one go in an old 305 Peugeot,and it cost me big time, straight to a mechanic