CriticalAffected: 2011-201540,000–100,000 miles

Ford Focus Mk3 1.0 EcoBoost 125bhp — Timing Chain Stretch and Tensioner Failure

The Focus Mk3 1.0 EcoBoost shares the same timing chain vulnerability as the Fiesta Mk7. Pre-2016 engines are the highest risk — chain rattle on cold start must be investigated immediately.

Severity

Critical

DIY Difficulty

Hard

Est. Cost

£600–£1200

OBD Codes

P0016P0017P0011

Component Diagram

Engine

Typical layout and location for the Engine assembly.

Reference Illustration

Symptoms

Rattling from front of engine on cold start
EML with P0016, P0017
Rough running or misfires
Chain slap sound under rapid acceleration

Root Cause

The plastic tensioner and guides wear prematurely. The chain stretches, eventually causing cam/crank timing to drift. Ford issued a TSB acknowledging the issue on 2012-2015 production engines.

How To Fix

Timing chain kit replacement (chain, tensioner, guides, VCT solenoid)
Check TSB history — ask if the timing chain has already been replaced under Ford goodwill
Use 5W-30 fully synthetic, max 6,000-mile oil change intervals going forward
Cost: £600-1,200 fitted

Estimated Repair Costs

Repair Option	Est. Cost (GBP)
DIY (parts only)	£240–£480
Independent Garage	£600–£1200
Main Dealership	£960–£1920

Other Faults on This Variant

Coolant Loss from Integrated Exhaust Manifold

Severe

2011-201860,000–120,000 miles£500–£900

The 1.0 EcoBoost's unique integrated exhaust manifold/cylinder head design causes head gasket stress. Coolant loss without visible leaks is a known issue on higher-mileage Focus Mk3 examples.

Turbocharger Boost Leak from Intercooler Pipe

Moderate

2011-201850,000–120,000 miles£30–£150

Boost pressure leaks from the plastic intercooler pipes and clamp connections on the 1.0 EcoBoost are common. A leak causes a noticeable flat spot and loss of performance under boost.

Water Pump Failure (Belt-Driven Internal)

Severe

2011-201880,000–140,000 miles£250–£500

The 1.0 EcoBoost uses a belt-driven water pump. When the pump fails, coolant circulation stops and the engine overheats rapidly. Because it is inside the engine, early detection requires vigilance.

Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.