Ford 1.0 EcoBoost (Fox) built October 2011 to October 2013: the degas pipe material can degrade, with coolant loss and overheating

At a glance

Severity

Critical destruction of the engine or gearbox, a safety risk, or an active safety recall.
Severity follows the worst documented outcome, not the average case.

Safety-relevant

Not flagged as safety-relevant.

In the Elgarde checklist

Critical entry: it caps the verdict of the whole inspection.

Documented in

UK

Which cars this covers

Only Ford 1.0 EcoBoost (Fox) engines built from October 2011 to October 2013. Ford's action covered the Focus; Ford says it also knows of coolant leakage on Fiesta, B-MAX and C-MAX 1.0L engines, so those are listed as likely rather than confirmed in scope.

Models in scope

Ford Focus, Ford Fiesta, Ford B-MAX, Ford C-MAX

Conditions on top of the model

• All of these must hold:
  • Engine: Ford 1.0 EcoBoost (Fox) turbo petrol
  • Production date: October 2011 to October 2013

Notes on scope

Ford's figures are for UK cars. Whether the same action applied outside the UK was not checked.

How to check whether a particular car is affected

Elgarde reads the conditions above and gives one of three answers for a car:

• Applies: every condition is confirmed for the car.
• Possible: at least one condition cannot be confirmed yet. The entry stays on the checklist, with a note on what to find out.
• Not applicable: a condition is clearly not met (for example a manual gearbox on a DSG entry). The entry is left off the checklist.

What to look for, and where

• Model: one of the models listed above
  The model name as on the registration document, e.g. Golf, 208, 320d.
• Engine code: Ford 1.0 EcoBoost (Fox) turbo petrol
  On the engine plate or block, or from a dealer VIN query. Displacement (P.1) and power in kW (P.2) on the registration certificate help narrow it down.
• Production month: October 2011 to October 2013
  The month the car was built (on the VIN plate or in the registration papers). It only matters when the year alone does not settle it.

When in doubt, treat the car as possible: asking one question too many costs less than missing a defect.

How the fault arises, as reported

According to Ford's own evidence, the pipe in the cooling system (the degas pipe) of the early 1.0L Fox was made of a material that could degrade. The pipe then leaks coolant, the engine can overheat, and sustained overheating can distort the engine and lead to seizure. Ford changed the material in production from October 2013. Ford says it found no evidence of cylinder head cracking on this engine. The legacy wording of this item mentioned the cylinder head; cylinder head cracking belongs to the 1.6 Sigma engine, a different engine and a different defect, and is not part of this record.

Reported symptoms

Early signs

• Coolant level dropping, coolant smell or residue around the pipe
• Engine temperature warnings

Later signs

• Overheating, engine distortion and seizure (Ford)

What to check when inspecting a car

• Documents and records. Check that the engine was built from October 2013 or that the degas pipe was replaced under Ford action 4S615 or later; ask for the invoice.Red flag: Engine built October 2011 to October 2013 with no record of the pipe.
• Visual check. With the engine cold, check the coolant level and look for dried coolant around the degas pipe and expansion tank.Red flag: Low level, crusted residue or a recently topped-up system.
• Diagnostic read-out. Read the fault memory and watch the temperature gauge on a test drive.Red flag: Overheating warning or a temperature that climbs above normal.

Repair and cost

Usual remedy

Replacement of the degas pipe with the updated part; engine repair or replacement if overheating has already damaged it.

No published repair cost is recorded in this dossier.

What the manufacturer and regulators have said

Manufacturer programme

Ford service action 4S615 (owner letters from April 2015, Non-Coded Action from mid-2017). From October 2018 Ford said it would make a 100% goodwill contribution to the cost of a repair at a Ford dealer for 1.0L Fox cooling issues, including engine replacement, and pay 100% of the cost of Ford parts at independent garages. These are UK terms stated in 2018; current eligibility was not checked. Sources: [1]

Official records and rulings

• Manufacturer statement · Ford of Britain, published by the UK House of Commons Transport Committee · UK Parliament committee publication 18188 · 2018-11-20
  Ford of Britain's letter to the Transport Committee (dated 13 November 2018, published 20 November 2018): the degas pipe material on the 1.0L Fox engine in the Focus could degrade, causing coolant loss and then overheating. Ford upgraded the pipe material in production from October 2013 and ran voluntary field service action 4S615 (owner letters from April 2015) on just over 44,600 UK Focus with engines built October 2011 to October 2013, 90.3% reworked at the time, upgraded to a Non-Coded Action in mid-2017. Ford says the DVSA did not classify it as a safety issue. Ford says it is aware of coolant leakage on Fiesta, B-MAX and C-MAX 1.0L Fox vehicles, that coolant loss can lead to engine distortion and seizure, that there is no evidence of cylinder head cracking on this engine, and that it knows of no proven cooling-system fires. From October 2018 Ford makes a 100% goodwill contribution to repair costs at Ford dealers for 1.0L Fox cooling issues. The publication record is linked; the letter itself was read from an Internet Archive copy (captured 2023-06-15) because the parliament.uk file is behind a bot challenge. [1] committees-api.parliament.uk

A recall or campaign record describes the vehicles in its scope, not a confirmed failure in any given car.

How common is it?

Evidence and sources

Each statement above traces to the sources below. Review status is shown for every source.

Automated source check: the source was opened and its claims, dates and figures were compared with this dossier by an automated check. It is not a human sign-off.

Reuse, attribution and corrections

Text and data: Elgarde, licensed under CC-BY-4.0, canon release 2026.10.1. Credit “Elgarde”, link to this page and say if you changed the text.

If you reproduce this dossier in a report on a specific car, show the disclaimer next to it.

Suggested citation

Elgarde, “Ford 1.0 EcoBoost (Fox) built October 2011 to October 2013: the degas pipe material can degrade, with coolant loss and overheating”, known-defect dossier ecoboost.coolant, canon release 2026.10.1, CC-BY-4.0, https://elgarde.com/defects/ecoboost.coolant/

Machine-readable version

• This dossier as JSON https://api.elgarde.com/api/v1/defects/ecoboost.coolant?lang=en
• Catalogue of all dossiers https://api.elgarde.com/api/v1/catalog?lang=en

Report a correction

Found a mistake, an outdated figure or a missing source? Open an issue at github.com/ElgardeCom/elgarde or write to support@elgarde.com. Mistakes are corrected.