Hi everyone,

I own a late 2015 Ford Focus 1.0 EcoBoost, which I bought two years ago. The car has now clocked 67k miles. Recently, I've noticed a coolant leak, although it's not very obvious. The coolant level drops more as I drive the car, but it remains stable when the car is parked.

I've refilled the coolant multiple times and took the car to a garage. The mechanic couldn't find the source of the leak despite pressurizing the system and checking all possible leak points. He suggested replacing the coolant bottle and cap, which I did, but the issue persists. The coolant level continues to drop slowly as the car runs.

Has anyone else experienced this issue or have any suggestions before I take the car back to the mechanic? Also, if you know of any affordable Ford specialists in Northern Ireland, I'd appreciate your recommendations.

Thanks in advance!

Check the expansion pipe that runs around the slam panel from the expansion tank.

Is the heater matrix leaking?

Failing that it could be the head gasket.

Have you had the wet belts changed??

1 hour ago, DaveT70 said:

Check the expansion pipe that runs around the slam panel from the expansion tank.

Is the heater matrix leaking?

Failing that it could be the head gasket.

Have you had the wet belts changed??

I have not changed the wet belts, but the mechanic suggested that I do so this December as my car reaches the 10-year mark.

I will check the expansion pipe and heater matrix. 

7 minutes ago, Arun Joy said:

I have not changed the wet belts, but the mechanic suggested that I do so this December as my car reaches the 10-year mark.

As I've said many times here on the forum: 10 years is the maximum age, it's not a target that has to be reached.

Do you expect to still own the car in another 10 years from December ? If the answer is no, then get the wet belts changed ASAP, unless the coolant leak turns out to be head gasket failure or a crack.

3 hours ago, unofix said:

wet belts changed ASAP

Correct.

And check the thermostat's back side.

Sounds like I had the exact same issue with my 2015 1L ecoboost a few months back. Wouldn't leak all the time, the problem went on for a few weeks and I would just top it up but in the end all the coolant would nearly leak out of the tank. My mechanic told me he changed the 2 coolant pipes (if that makes sense, that's all he told me). The pipes only cost €40 anyway and I haven't had any issue since. 

Thank you all for your responses. I will review the potential causes and replace the wet belt as soon as possible. Please let me know if anyone thinks of any other possible causes for the issue. I will also provide an update once I resolve the problem.

I have exactly the same issue. Bought mine 6 months ago, wet belt replaced about a year ago and losing coolant fast. I took it to a very reliable garage and they pressure tested, said it was one of the plastic bleed pipes and replaced that, then did 250 miles in a day and it was nearly running dry by the end of it so not sure what to do the coolant only drops when its been running, sits and doesnt leak.

I was worried about head gasket but no other symptoms have shown. No significant white smoke other than when its been freezing cold and everyones cars are doing it, oil is the usual amber colour and holding correct levels, no oil slick in the coolant after i've done any length of drive, no build up under the oil fill cap, no 'sweet smell' thats apparently common so i'm out of the usual tick boxes! Thinking it might be one of the pipes that has cracked past the firewall but no idea.

Please do update when you've found the solution and had it fixed would be great to get mine sorted.