The manual states the correct spec is WSS-M97B44-D, but I can see coolant online that meet this spec that are both red and orange. I'm not sure what the original OEM colour is. Does it even matter as long as it meets the spec according to the item description?

Then there are universal antifreeze that is yellow which apparently match my car if I input my registration into Euro Car Parts.

The colour doesn't matter as long as it's the right spec.

The original looks both pink and orange depending on how the light hits it in different containers.

If the universal antifreeze is Prestone then they do claim that can be safely mixed with any other.

The latest Ford coolant is bright Yellow and no longer Pink/Orange.

Both the Yellow and the Pink/Orange can be mixed without any problems.

I decided to get the cooling system flushed since I'm not sure whether it has been done in the past.

While the coolant was (almost) out of the system, I noticed debris at the bottom of the expansion tank. I was told this is normal and the debris would settle back in the tank even if the tank was removed and rinsed.

I assume the debris are from the internal components (hoses, radiator) degrading over the 10 years. Is some debris in the tank expected on Fiestas?

...late to the party, but I strongly recommend Prestone. It does safely mix with anything in there (remember that you have no idea what previous owners have put in) is a very efficient long-lived coolant, according to the internet/manufacturer, and costs buttons if you get it from Tescos when on offer. I use it in all my vehicles.. well all the ones that have coolant anyway 😁

On 5/22/2026 at 5:35 PM, landfall said:

I decided to get the cooling system flushed since I'm not sure whether it has been done in the past.

While the coolant was (almost) out of the system, I noticed debris at the bottom of the expansion tank. I was told this is normal and the debris would settle back in the tank even if the tank was removed and rinsed.

I assume the debris are from the internal components (hoses, radiator) degrading over the 10 years. Is some debris in the tank expected on Fiestas?

Normal on every car with a coolant system - if you've flushed the coolant, then 98% of the debris has been removed, so why wouldn't you remove the final bits? Or was this the excuse from the mechanic who flushed the system, but hasn't cleaned out the expansion tank?

I went with "ERRECOM Red Cool" since the spec was listed in the description. I wasn't too sure what "universal" exactly meant with Prestone. I can consider Prestone next time the coolant is flushed.

The excuse was from the garage. Next time I'll insist on cleaning the expansion tank but if the debris won't cause any damage, then I can leave it as is for now. I may even have a go at flushing the coolant myself next time.

Garages do things quickly - otherwise they wouldn't make a profit. Owners will always do any task better. You might not have the tools, crane/lift whatever, but if it's a straightforward job, I always do it myself. For example the front wheel bearings on a Fiesta are a nightmare, so I paid someone else to do that. Flushing the coolant? You can certainly do that. Just read-up about it first, just in case there's a mad/hidden bleed point, or whatever.