Hyundai Tucson
Updated 1.6 CRDi with SCR cat and optional 48V mild hybrid. Cleaner, smoother, and more frugal than the engine it replaced.
Modern SUV, comfort over thrills
The most polished Tucson yet — comfortable and modern, but dynamic fireworks are not on the menu.
Engine Weaknesses 7
The EGR system on the 1.6 CRDi D4FE is prone to soot deposits in urban use. Cleaning the EGR valve and intake manifold is recommended to prevent swirl flap breakage.
Symptoms: Power loss, rough running, check engine light, EGR fault codes (P0400–P0409).
The diesel particulate filter of the Smartstream D4FE does not fully regenerate in predominantly short-trip use. The engine enters limp mode; complete DPF cleaning or replacement becomes necessary.
Symptoms: Limited engine output (limp mode, max. 3,000 rpm), check engine light, DPF warning indicator, unpleasant smell after failed regeneration.
The variable turbine geometry (VTG) of the Smartstream turbocharger tends to stick with carbon build-up. Vehicle enters limp mode; sometimes only cleaning is needed, sometimes the turbo must be replaced.
Symptoms: Sudden power loss, limp mode, irregular turbo response depending on driving situation.
D4FE injectors are prone to uneven spray patterns and leaks at the copper sealing washers. Diesel can enter the oil (oil dilution), compromising lubrication.
Symptoms: Hesitation on acceleration, difficult cold start, rising oil level without topping up, fuel smell in engine oil.
The EGR valve on the D4FE is prone to heavy soot deposits, causing rough running, increased fuel consumption and DPF problems. The situation worsens significantly with short-trip use.
Symptoms: Rough idle, power loss, increased consumption, DPF warning light
Piezo injectors on the D4FE can weaken: fuel rail pressure builds only slowly on start attempts (50–80 bar instead of 140 bar), causing difficult cold start and power drops.
Symptoms: Engine starts poorly, starter cranks for a long time, pump needs to be primed several times
The D4FE's DPF clogs prematurely in predominantly short-trip use. Regeneration cycles can multiply when the EGR valve is stuck; replacement costs up to €2,400.
Symptoms: DPF warning light, frequent regeneration, power reduction, increased consumption
Vehicle Weaknesses 9
The Tucson NX4 was subject to a recall due to possible failure of the brake servo. Affected vehicles must be checked by the dealer and repaired if necessary.
Around 200 Tucson NX4 had to visit the workshop due to faulty airbag installation. The hybrid control unit was also updated with software on a further approximately 4,000 vehicles due to limited immobiliser functionality.
The large infotainment system of the NX4 freezes regularly or restarts. Software updates from the dealer can help, but the problem is widespread.
The DCT in the NX4 shows slight juddering in some driving situations, especially when setting off on a hill or in stop-and-go traffic.
The 48-volt electrical system in early Tucson NX4 examples generates fault messages without a stored diagnostic code. Start-stop switches off uncontrollably, starter responds with a delay.
Tucson NX4 headlights show condensation moisture inside, which impairs visibility quality and can damage the LED units over time. Warranty replacement is generally straightforward.
Several Tucson NX4 owners report rattling interior panels and poorly fitting wheel arch covers appearing shortly after delivery. Dealer correction is usually uncomplicated.
Tucson NX4 owners report insufficient heating performance at sub-zero temperatures. Engine stays below 50°C operating temperature, resulting in increased fuel consumption and inadequate cabin temperature.
The mild hybrid 48-volt network shows sporadic fault messages and causes start-stop system failure. Several owners report complete power shutdowns while driving and necessary control unit resets.
Reports & Tests
934 owner complaints filed with NHTSA (2020–2026). Most reported: Engine (231), Collision Avoidance (188), Other (172).