Ford Focus Mk3 Radiator: Specs, Fitment & Common Faults

The Mk3's 1.0 EcoBoost has a well-documented degas bottle cracking issue — serious enough to be referenced in a UK Parliament transport committee document.

Generation covered: this guide is for the third-generation Focus, built 2011–2018 (commonly the 2014–2018 registered examples still in daily use). The newer Mk4 Focus (2018–) uses different part numbers throughout — check your V5C logbook or VIN if you're unsure which generation you have.

Illustration for editorial purposes

The 1.0 EcoBoost's Degas Bottle Has a Well-Documented Cracking Tendency

Across the 1.0 EcoBoost family generally (primarily 2012-2017 production), the plastic degas bottle (coolant reservoir) and its connecting hoses have a well-documented tendency to develop hairline cracks as the plastic ages and heat-cycles over years of use — serious enough that a UK Parliament transport committee document specifically references "failure of the degas pipe affecting 1.0L Fox engines" as a known issue Ford was asked to address. Watch for dropping coolant levels requiring more than one top-up between services, a sweet smell from the engine bay, or white smoke from the exhaust on starting — all worth investigating promptly rather than simply topping up and continuing to drive.

Worth knowing: a genuine UK recall (reference R/2020/089, 2020) also covered certain Kuga and Puma models specifically for a related coolant leak risk — worth checking your own registration via the DVSA recall checker even if your model wasn't part of that specific recall, since the underlying degas bottle weak point affects the wider 1.0 EcoBoost range.

The Part That Keeps Everything Else From Cooking

Nothing about this component is glamorous, but almost every serious engine failure that isn't wear-related traces back to a cooling system problem left unaddressed. Catching the early signs here is genuinely cheap insurance against a much bigger bill.

Before you buy: radiator size and design vary significantly by engine size, transmission type, and whether your car has air conditioning. Always confirm against your VIN before ordering.

OEM Part Number: CV6Z-8005-U

Accuracy note: radiator specification depends on engine, transmission type, and whether the car has an automatic gearbox oil cooler built in — confirm your transmission type before ordering, since fitting a manual-spec radiator to an automatic car omits a cooling circuit it needs.

Most petrol/diesel variants, 2013–2018	Ford OEM: CV6Z-8005-U
1.0 EcoBoost, 2015–2016	Ford OEM: CV6Z-8005-W
Automatic transmission models (torque converter)	Includes an internal transmission fluid cooler as a separate circuit within the radiator tank — not present on manual-spec radiators; if this internal cooler fails, coolant and transmission fluid mix into a pink, milky fluid nicknamed the "strawberry milkshake of death" by owners and technicians, which can destroy the transmission if not caught quickly
Powershift (dual-clutch automatic)	Genuinely uses a separate standalone transmission oil cooler mounted ahead of the radiator and condenser, rather than an internal circuit built into the radiator itself — a different cooling architecture from the older-style automatic's integrated design

Ford revised the Focus Mk3's radiator part number more than once across its production run, and automatic-transmission cars use a version with an additional internal cooler circuit that manual cars don't have. Confirm your transmission type and engine before ordering, since the wrong version will fit physically but won't cool the transmission fluid correctly.

What It Does

The radiator transfers heat from the engine coolant to the surrounding air, keeping engine temperature within a safe operating range. On automatic versions, it often also cools transmission fluid through a separate internal circuit — one more reason the correct part number matters so much here.

Faults, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Radiator Guide for the three common failure modes, confirming fitment against your VIN, and OEM vs aftermarket guidance.

More Ford Radiator

The same part, covered across other Ford models.

Ford Focus Mk3 Radiator: Specs, Fitment & Common Faults

The 1.0 EcoBoost's Degas Bottle Has a Well-Documented Cracking Tendency

OEM Part Number: CV6Z-8005-U

Shop for This Part on eBay