Buick Encore GX GEM

Turbocharged 1.2-liter three-cylinder with direct injection and around 137 hp, designed as a downsized base engine. The tricky part is the wet timing belt (belt running in oil) combined with pure direct injection: fuel dilution thins the oil, the belt degrades over time and debris can clog the oil pickup — in the worst case oil-pressure loss leads to rod-bearing failure. The engine is very new (2024+), yet early total failures with knocking and a punched-through rod are piling up, sometimes well under 20,000 miles. Short oil-change intervals (8,000 km at the latest, sooner on short trips) and only approved dexos1 Gen3 oil are mandatory. When buying used, listen for cold-start knock/rattle, check oil level and coolant use, and verify open recalls (ignition timing after stop/start).

• !! Wet timing belt (belt-in-oil) from 90,000 km

  The 1.2 turbo uses a wet timing belt running in oil. Fuel dilution from direct injection thins the oil and degrades the belt; debris clogs the oil pickup screen and can cause oil-pressure loss and engine failure. Frequent oil changes and timely belt replacement are essential.

  Symptoms: Oil-pressure warning light, clatter/ticking, power loss; with advanced wear, belt debris in the oil and on the pickup screen, and in extreme cases engine misfire/failure.
  1,400–2,200 $
  Ad wet timing belt 1.2 Ecotec LIHbelt-in-oil kit Chevrolet Trax 1.2oil pickup screen 1.2 Turbo LIH
• !! Turbo: wastegate rattle and intercooler icing from 100,000 km

  The 1.2's small turbo suffers wastegate linkage wear causing a cold-start rattle, often with underboost codes (P0299). In cold weather humid charge air can ice up the intercooler and cut power. Oil starvation from belt debris can further damage the turbo.

  Symptoms: Cold-start rattle, boost loss, power hole, check-engine light (P0299); in the cold, whistle and sudden power drop, possibly blue smoke.
  800–2,000 $
  Ad turbocharger 1.2 Turbo LIHwastegate actuator Chevrolet Trax 1.2intercooler Trax 1.2
• ! Intake valve carbon buildup (direct injection) from 80,000 km

  The 1.2 turbo is direct-injection only, so the intake valves are never washed by fuel. Crankcase vapors bake deposits onto the valves — throttle response degrades over the years. The only fix is mechanical cleaning (walnut blasting), which isn't in the service schedule.

  Symptoms: Increasingly dull throttle response, rough idle, later misfires and slightly rising consumption.
  300–700 $
  Ad intake valve cleaning 1.2 Turbo LIHwalnut blasting Chevrolet Trax 1.2PCV valve 1.2 Ecotec

Turbocharged 1.3-litre three-cylinder producing 116 kW and around 174 Nm, with direct injection and a water-cooled charge-air manifold. Unlike its smaller 1.2-litre sibling, the valvetrain runs on a timing chain rather than an oil-bath wet belt – this avoids the costly belt service and makes the valvetrain noticeably more durable. The core architecture and chain are considered long-lived; the weak spots sit in the periphery: the electric coolant flow control valve (replacing a conventional thermostat) can throw fault codes during break-in, the wastegate actuator is prone to boost dropouts, and by design carbon deposits build up on the intake valves from mid mileage onwards. Stick to 0W-20 changes every 8,000 km and keep an eye on boost and oil level – then a solid, economical turbo triple.

• !! Coolant flow control valve failure – P26BB from 40,000 km

  The electric coolant flow control valve replaces the conventional thermostat and can stick. GM bulletin 21-NA-256 documents fault code P26BB: the engine stays too cold or risks overheating. Affected valve part 12716827 (superseded by 25204466).

  Symptoms: Check engine light with P26BB, slow warm-up in winter or conversely an overheat warning, erratic temperature gauge, may self-resolve during early break-in
  200–550 $
  Ad coolant flow control valve 12716827thermostat 25204466 L3Tcoolant control valve P26BB
• !! Wastegate actuator sticking – boost loss P0299 from 60,000 km

  The turbocharger wastegate regulator drifts or sticks and boost collapses. Fault code P0299 (underboost), often with cold-start rattle. GM bulletin 23-NA-058 provides a test procedure before replacing the whole turbo. Early builds sometimes needed a full turbo replacement.

  Symptoms: Reduced Engine Power message, sudden power drop to 25-35 mph, limp mode, cold-start rattle, check engine light P0299
  300–1,400 $
  Ad wastegate actuator L3Tturbocharger 1.3 L3Twastegate regulator valve P0299
• ! Elevated oil consumption at higher mileage from 90,000 km

  From mid mileage onwards owners report noticeable oil consumption – sometimes around 1 litre per 3,000 km, with no visible leak or blue smoke. Direct injection with fuel dilution encourages it. Regular dipstick checks are needed; some owners switch to 0W-30 as a remedy.

  Symptoms: Oil level dropping between intervals, low-oil warning, no visible puddle under the car, no blue smoke, dipstick checks recommended
  30–300 $
  Ad motor oil 0W-20 dexos1 Gen3oil level sensor L3TPCV valve 1.3 turbo

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