Ford Focus
1.0 EcoBoost mHEV in the Focus DEH with 48V mild hybrid. Belt-integrated starter-generator replaces the conventional alternator. Chain-driven. The electrical system requires additional maintenance attention.
Lively Diesel
155 hp TDCi in the Mk4: decently powered, good efficiency. Almost sporty, but not quite.
Engine Weaknesses 6
The front cover seal on early 1.0 EcoBoost engines (up to approximately February 2015) was not oil-resistant. Oil attacks the seal, followed by gradual coolant loss. TSI 15-1070 addresses the issue.
Symptoms: Coolant level dropping with no visible external leak, temperature warning, whitish steam from engine bay.
The 48V mild hybrid belt-starter-generator (BSG) and associated power electronics can develop faults prematurely. Replacement is costly.
Symptoms: Mild hybrid system warning, no regenerative braking, 12V battery not charging correctly.
Fragile plastic couplings on the coolant circuit. Embrittlement leads to leaks; particularly relevant as the mHEV system relies on stable operating temperature.
Symptoms: Dropping coolant level, temperature warning, coolant smell.
The wastegate linkage on the small turbocharger rattles due to a leaking vacuum actuator. Leads to power loss and fault code P0299 (underboost).
Symptoms: Rattling noise from the turbo area, noticeable power loss, fault code P0299, engine in limp mode.
Direct injection leads to carbon deposits. Despite mHEV boost, frequently used on short trips, which accelerates buildup.
Symptoms: Stumble on cold start, power loss at higher mileages.
The belt-integrated starter-generator (BiSG) on the 1.0L mHEV transmits noticeable vibration into the drivetrain at 2,000β3,000 rpm. Ford classifies the noise as design-related; steering wheel and gear lever vibrate measurably.
Symptoms: Droning noise at 2,000β3,000 rpm, vibrations at steering wheel and gear lever especially under load
Vehicle Weaknesses 6
Recall for 9,858 vehicles (OctβDec 2018) due to bolts at the brake pedal-to-master cylinder connection being at risk of fracture. Complete brake failure is possible.
Cracking and squeaking from the electric steering on parking manoeuvres. Isolated cases of steering failure with a warning message on cold start. Usually resolved under warranty.
On the 155 hp MHEV variants with manual gearbox, the synchro rings for 1st and 2nd gear wear prematurely. Failures documented from as low as 22,000 km. Ford does not offer improved replacement parts.
Early 2018β2019 model years had significant electrical issues: failed parking sensors, a faulty SYNC 3 system, defective stop-start and Auto Hold functions. Software updates resolve many problems.
The underbody has inadequate corrosion protection: weld seams unsealed, cavities open. Rust forms early in splash zones. The exhaust system corrodes quickly.
The SYNC 3 system freezes regularly on early DEH models (2018β2020), stops responding to touch input or shows a black screen. Software updates improve the issue.
Reports & Tests
800 owner complaints filed with NHTSA (2018β2024). Most reported: Powertrain (302), Engine (221), Fuel System (123).