Ford 1.0 EcoBoost (Fox) with oil-bath timing belt: the oil pump belt, its tensioner or belt debris can cut oil pressure
Ford recall 23V-905 (US, filed December 2023) covers 139,730 Focus and EcoSport with the 1.0L engine and 6F15 automatic: according to Ford, the oil pump belt tensioner arm may fracture or separate, or the belt may lose teeth, causing loss of oil pressure. In July 2026 NHTSA opened engineering analysis EA26-004 on 135,551 Fiesta, Focus and EcoSport. Its opening resume states that timing belt material may degrade and clog the oil pump pick-up screen; in the failure data provided to the investigation the average failure mileage was about 70,000 miles and 98% of failures came before the 150,000-mile belt interval. This is an open investigation, not a recall. NHTSA also reports that Ford announced a non-safety customer programme for 1.0L Fox Classic engines worldwide that cuts the belt interval to 100,000 miles or 6 years. No European recall was found.
Dossier revision 1 · data updated 2026-10-13 · canon release 2026.10.1
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
- Yes: a documented failure mode involves loss of drive, braking, steering, airbags or fire while driving.
- In the Elgarde checklist
- Ordinary entry: it does not cap the verdict by itself.
- Documented in
- US, UK, EU
Which cars this covers
Only Ford 1.0 EcoBoost (Fox) petrol engines with the oil-bath belts. The US documents cover Fiesta, Focus and EcoSport; the NTN-SNR supplier table also lists B-MAX, C-MAX, Mondeo and Puma with this belt. Parkers says Ford moved to a timing chain in late 2018 and that later Fiesta, Focus and Puma should have a chain, but early ones may still have the belt, so check by VIN or engine code. Recall 23V-905 itself covers only US Focus and EcoSport with the 6F15 automatic.
- Models in scope
- Ford Fiesta, Ford Focus, Ford EcoSport, Ford B-MAX, Ford C-MAX, Ford Mondeo, Ford Puma
- Conditions on top of the model
- All of these must hold:
- Engine: Ford 1.0 EcoBoost (Fox) turbo petrol
- All of these must hold:
- Notes on scope
- The engine code list comes from a supplier table (NTN-SNR, 2025), the only code source found, and is medium confidence. The same table also lists Transit and Tourneo Courier and Connect vans, which are not in the model list.
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.
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
The 1.0 EcoBoost (Fox) drives the camshafts and the oil pump with belts that run in engine oil. In Ford's recall 23V-905 the oil pump belt tensioner arm can fracture or separate, or the belt can lose teeth, and oil pressure is lost; Ford says the arm retention joint is not robust to vibration. NHTSA's later analysis EA26-004 describes a second path: timing belt material may degrade and clog the mesh pick-up screen of the oil pump, which cannot be serviced without removing the engine. Dayco, the belt supplier, advises checking the oil for a petrol smell and checking the strainer. The causes are as stated by Ford in the recall and by NHTSA in an open investigation; the pick-up screen blockage is an investigation finding, not a recall.
Reported symptoms
Early signs
- Oil pressure warning light or low oil pressure reading
- Petrol smell in the engine oil, or belt debris found at service (Dayco)
Later signs
- Loss of oil pressure and engine failure (Ford recall 23V-905)
What to check when inspecting a car
- Documents and records. Ask for proof of every timing belt and oil pump belt replacement, and check the VIN for recall 23V-905 (US cars) and for any Ford customer programme.Red flag: No belt service record on a car older than 6 to 10 years, or recall 23V-905 open.
- Visual check. Check the engine oil: smell for petrol and look for dark flakes or debris on the dipstick and in the filler area.Red flag: Petrol smell, black flakes or debris in the oil.
- Diagnostic read-out. Read the fault memory and watch the oil pressure indicator at cold start and at idle when warm.Red flag: Oil pressure warning at any time, even briefly.
Repair and cost
- Usual remedy
- Recall 23V-905 fits a redesigned bolted tensioner with a shorter arm and a belt with updated material. Otherwise belt replacement at the interval; in the UK Parkers quotes about 800 to 2,000 GBP.
- No published repair cost is recorded in this dossier.
What the manufacturer and regulators have said
Manufacturer programme
US recall 23V-905 is free of charge and applies to US vehicles only. According to NHTSA's EA26-004 resume, in June 2026 Ford told NHTSA of a non-safety customer satisfaction programme for 1.0L Fox Classic engines worldwide: a revised belt interval of 100,000 miles or 6 years, and reimbursement for eligible owners who paid for earlier engine repairs linked to the belt. How it is applied in each European country was not found; ask a Ford dealer with the VIN. Sources: [1], [4]
Official records and rulings
- Recall · NHTSA · NHTSA 23V905 / Ford 23S64 · 2024-04-04
Ford safety recall covering 139,730 vehicles: Focus model years 2016-2018 (built 24 March 2015 to 4 May 2018) and EcoSport 2018-2022 (built 3 April 2017 to 12 October 2021), all with the 1.0L engine and 6F15 automatic. The oil pump belt tensioner arm may fracture or separate, or the belt may lose teeth, causing loss of oil pressure. Ford states the arm retention joint is not robust to vibration. Ford counts 2,099 warranty claims between 10 June 2016 and 6 October 2023 and one crash allegation with two injuries. Remedy: redesigned bolted tensioner and a belt with updated material. [1] static.nhtsa.gov - Regulator investigation · NHTSA · NHTSA PE23-015 · 2024-02-14
NHTSA preliminary evaluation opened 20 September 2023 and closed 14 February 2024 after Ford filed recall 23V-905. Counts in the resume: 419 ODI complaints, 2,707 manufacturer reports, 2,099 warranty claims. [2] static.nhtsa.gov - Regulator investigation · NHTSA · NHTSA PE25-020 · 2025-12-18
NHTSA preliminary evaluation opened 18 December 2025 on Fiesta MY2015-2017 and Focus MY2015-2018 with the 1.0L engine and a manual transmission: 44 complaints, about 10,473 vehicles. [3] static.nhtsa.gov - Regulator investigation · NHTSA · NHTSA EA26-004 · 2026-07-31
NHTSA engineering analysis opened 31 July 2026 on 135,551 vehicles (Fiesta MY2014-2017 and Focus MY2015-2018 with manual transmission; EcoSport MY2018-2021 and Focus MY2016-2018 with automatic). NHTSA states the timing belt material may degrade and clog the oil pump pick-up screen, with average failure at about 70,000 miles and 98% of failures before the 150,000-mile belt interval, also with routine oil maintenance. The screen is not serviceable without removing the engine. NHTSA believes there is an unreasonable risk to safety; this is an investigation, not a recall. On 2 June 2026 Ford told ODI about a non-safety customer satisfaction programme: belt interval cut from 150,000 miles to 100,000 miles or 6 years, with reimbursement of eligible earlier engine repairs. NHTSA describes the programme as covering vehicles with the 1.0L Fox Classic timing belt globally. [4] static.nhtsa.gov
A recall or campaign record describes the vehicles in its scope, not a confirmed failure in any given car.
How common is it?
Recall population
This counts vehicles in the scope of a recall. It is not a failure rate.
- Figure
- 139,730
- Population
- Focus MY2016-2018 and EcoSport MY2018-2022 with the 1.0L engine and 6F15 automatic in US recall 23V-905
- Geography
- US
- What was counted
- Vehicles recalled
- Confidence grade
- C: manufacturer, recall or large-survey figure; method only partly known
- Caveats
- A recall population counts vehicles in scope, not vehicles that failed. It is not a failure rate and says nothing about Europe.
- Sources
- [1]
Compensation claims filed
This counts claims filed. It is not a failure rate and not a count of confirmed defects.
- Figure
- 2,099
- Population
- Warranty claims counted by Ford for the oil pump belt tensioner and belt in the 23V-905 population, 10 June 2016 to 6 October 2023
- Geography
- US
- What was counted
- Warranty claims
- Confidence grade
- C: manufacturer, recall or large-survey figure; method only partly known
- Caveats
- A manufacturer-reported count of claims, not a rate; it has no denominator on a comparable basis. The separate NHTSA investigation EA26-004 covers 135,551 vehicles, which is its scope and not a failure count.
- Sources
- [1], [2]
No reliable figure
No reliable figure for how many cars are affected is recorded for this entry. This is stated on purpose: a missing number is not a low number.
No verified share of affected engines that suffered a belt or oil pump failure has been published. The figures above are recall scope and warranty claims, not rates. Sources: [1], [4]
Evidence and sources
Each statement above traces to the sources below. Review status is shown for every source.
| Publisher | Title | Date | Type | Tier | Confidence | Links | Review |
|---|---|---|---|---|---|---|---|
| NHTSA | [1] Recall 23V-905 Part 573 report - Ford, oil pump drive belt tensioner (1.0L) NHTSA 23V905 / Ford 23S64 Ford safety recall covering 139,730 vehicles: Focus model years 2016-2018 (built 24 March 2015 to 4 May 2018) and EcoSport 2018-2022 (built 3 April 2017 to 12 October 2021), all with the 1.0L engine and 6F15 automatic. The oil pump belt tensioner arm may fracture or separate, or the belt may lose teeth, causing loss of oil pressure. Ford states the arm retention joint is not robust to vibration. Ford counts 2,099 warranty claims between 10 June 2016 and 6 October 2023 and one crash allegation with two injuries. Remedy: redesigned bolted tensioner and a belt with updated material. | 2024-04-04 | Recall | 1 · primary source | high | static.nhtsa.gov opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
| NHTSA | [2] Investigation PE23-015 closing resume - Ford 1.0L oil pump belt NHTSA PE23-015 NHTSA preliminary evaluation opened 20 September 2023 and closed 14 February 2024 after Ford filed recall 23V-905. Counts in the resume: 419 ODI complaints, 2,707 manufacturer reports, 2,099 warranty claims. | 2024-02-14 | Regulator investigation | 1 · primary source | high | static.nhtsa.gov opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
| NHTSA | [3] Investigation PE25-020 opening resume - Ford Fiesta and Focus 1.0L manual NHTSA PE25-020 NHTSA preliminary evaluation opened 18 December 2025 on Fiesta MY2015-2017 and Focus MY2015-2018 with the 1.0L engine and a manual transmission: 44 complaints, about 10,473 vehicles. | 2025-12-18 | Regulator investigation | 1 · primary source | high | static.nhtsa.gov opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
| NHTSA | [4] Investigation EA26-004 opening resume - Ford 1.0L engine oil pump pick-up screen NHTSA EA26-004 NHTSA engineering analysis opened 31 July 2026 on 135,551 vehicles (Fiesta MY2014-2017 and Focus MY2015-2018 with manual transmission; EcoSport MY2018-2021 and Focus MY2016-2018 with automatic). NHTSA states the timing belt material may degrade and clog the oil pump pick-up screen, with average failure at about 70,000 miles and 98% of failures before the 150,000-mile belt interval, also with routine oil maintenance. The screen is not serviceable without removing the engine. NHTSA believes there is an unreasonable risk to safety; this is an investigation, not a recall. On 2 June 2026 Ford told ODI about a non-safety customer satisfaction programme: belt interval cut from 150,000 miles to 100,000 miles or 6 years, with reimbursement of eligible earlier engine repairs. NHTSA describes the programme as covering vehicles with the 1.0L Fox Classic timing belt globally. | 2026-07-31 | Regulator investigation | 1 · primary source | high | static.nhtsa.gov opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
| Parkers | [5] Ford wet belt issues explained UK consumer motoring site (updated 9 September 2026): lists the Ford models with the 1.0 EcoBoost oil-bath belt (B-Max, C-Max, EcoSport, Fiesta, Focus, Mondeo); says Ford switched to a timing chain in late 2018 and that later Fiesta, Focus and Puma should have a chain, though early examples may have the belt, so the VIN should be checked; says Ford recommends belt replacement at 10 years or 150,000 miles and treats the belt as a maintenance item; quotes UK replacement costs of about 800 to 2,000 GBP. The article mixes facts and opinion; used here only for applicability and cost, attributed to Parkers. | 2026-09-09 | Specialist press | 2 · press or analysis | medium | parkers.co.uk opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
| Professional Motor Mechanic | [6] Maintaining the timing belt on a Ford Fox engine UK workshop trade magazine, article by the belt supplier Dayco: Dayco is the original-equipment supplier of both the timing belt and the oil pump drive belt on this engine; the service interval is 150,000 miles or 10 years; Dayco advises checking the oil for a petrol smell and checking the oil strainer when servicing. | 2022-10-31 | Specialist press | 2 · press or analysis | medium | pmmonline.co.uk opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
| NTN-SNR | [7] TECHinfo: 1.0 EcoBoost wet belt and oil pump belt Parts supplier technical note (April 2025) on the 1.0 EcoBoost wet timing belt, including a kit with the 46-tooth oil pump belt. It lists B-Max, C-Max, Grand C-Max, EcoSport, Fiesta to 2019, Focus to 2018, Mondeo, Puma from 2019 and the Transit and Tourneo Courier and Connect, with engine codes. The code list is a supplier table and is used with medium confidence. | 2025-04 | Technical analysis | 2 · press or analysis | medium | ntn-snr.com opened 2026-10-13 Archive copy | automated source check 2026-10-13 |
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.
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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.
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Suggested citation
Elgarde, “Ford 1.0 EcoBoost (Fox) with oil-bath timing belt: the oil pump belt, its tensioner or belt debris can cut oil pressure”, known-defect dossier ecoboost.wetbelt, canon release 2026.10.1, CC-BY-4.0, https://elgarde.com/defects/ecoboost.wetbelt/
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