Toyota Wish: common faults & what to check

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The 1ZZ-FE 1.8-litre engine fitted to ZE10 Wish models suffers from a design flaw in the piston oil control rings. The narrow, low-tension rings introduced for reduced internal friction are prone to carbon fouling and sticking in their grooves, preventing them from scraping oil from the cylinder walls. The engine consumes engine oil at rates exceeding 1 litre per 1,000 km without producing visible blue smoke at idle, making the problem easy to overlook until severe engine damage occurs. This defect was the subject of a US class action lawsuit settled by Toyota in 2012 covering multiple 1ZZ-FE applications.

Where to look: Engine internals — piston ring land grooves on all four pistons

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The 3ZR-FAE uses a water pump with a plastic impeller that is susceptible to erosion and de-bonding from the shaft at high mileage, typically beyond 150,000 km. Electrochemical corrosion from degraded or non-OEM coolant accelerates erosion of the impeller vanes, progressively reducing coolant flow without any visible external leak. The engine may overheat under load or at highway speed while remaining near-normal temperature at idle. In advanced cases the impeller can spin free of the pump shaft entirely, causing rapid overheating. This is an explicitly documented weakness of the 3ZR-FAE and is a known cause of head gasket failure if not caught early. Mechanics widely report the 3ZR-FAE water pump as one of the most problematic components on this engine.

Where to look: Front of engine block, driven by the accessory serpentine belt

Parts involved: Water pump.

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The U341E four-speed automatic transmission fitted to the ZE10 Wish 1.8 develops a characteristic shudder through the drivetrain at light throttle in the 60–100 km/h range when the torque converter clutch attempts to lock. The friction material on the lock-up clutch glazes over time, particularly when ATF service intervals are ignored. The shudder can be mistaken for engine misfire but disappears when the converter clutch is disengaged by a sharp throttle blip or by selecting third gear manually. Contaminated fluid accelerates lining degradation and can eventually cause total converter failure.

Example of the part — not this vehicle

Where to look: Torque converter lock-up clutch pack inside bell housing

Parts involved: Torque converter.

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4-speed U340E automatic transmission develops torque converter lock-up clutch shudder under light throttle at highway cruise.

Example of the part — not this vehicle

Where to look: Automatic transmission and torque converter

Parts involved: Torque converter.

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The hydraulic timing chain tensioner on the 2ZR-FAE relies on pressurised oil to maintain chain tension. When the tensioner's internal check valve wears or the plunger O-ring degrades, oil drains back from the tensioner bore during extended shutdown periods, leaving the chain slack for the first several seconds of each cold start until oil pressure rebuilds. This repeated momentary slack accelerates chain stretch and guide-rail wear, and if ignored can ultimately allow the chain to jump a tooth, causing significant valve-to-piston contact damage.

Example of the part — not this vehicle

Where to look: Front of engine, timing chain cover, tensioner on the left (intake) side of the block

Parts involved: Timing chain.

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The 1AZ-FSE D4 direct injection fuel injector O-rings harden and shrink causing fuel to weep around the injector body into the cylinder head, causing a raw petrol smell from the engine bay and rough running.

Example of the part — not this vehicle

Where to look: High-pressure fuel injectors in cylinder head

Parts involved: Fuel injector.

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Both the 1ZZ-FE (ZE10) and 2ZR-FAE (ZE20) engines use a coolant-lubricated water pump whose shaft seal deteriorates from approximately 120,000–150,000 km. The mechanical face seal between the impeller shaft and the pump housing begins to weep coolant, which is deposited on the accessory belt and pulley, and onto the front of the engine block below the pump. If undetected the coolant loss leads to overheating, and the coolant contaminating the belt causes premature belt failure. On the timing chain 2ZR-FAE the water pump is externally mounted and accessible; on the 1ZZ-FE it is driven off the timing belt and the belt must be replaced simultaneously.

Where to look: Water pump shaft seal at front of engine block, below alternator on 1ZZ-FE; below intake manifold on 2ZR-FAE

Parts involved: Water pump.

Can't confirm for this car

The 3ZR-FAE EGR valve accumulates carbon deposits on the valve seat and stem with mileage, causing it to stick in a partially open position. When stuck open, the EGR introduces excess exhaust gas into the intake charge at inappropriate times, diluting the air-fuel mixture and creating a lean condition. This triggers P0171 (System Too Lean Bank 1) and random misfire codes. Idle quality deteriorates and the engine stumbles at low speed. High-mileage grey imports that have operated on poor fuel or infrequent servicing are most affected. EGR cleaning can restore function in mild cases; replacement is required when the valve body is damaged or seized.

Where to look: EGR valve mounted on intake manifold, driver side of engine

Parts involved: EGR valve.

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EPS system can develop a fault causing loss of power assistance.

Where to look: EPS column motor and control unit

Parts involved: Steering rack.

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The AE20 Wish uses a column-mounted electric power steering (EPS) unit with a brushed DC motor driving the steering column via a worm gear. As the carbon brushes in the motor wear down, electrical resistance increases and the motor delivers inconsistent or reduced assist. The EPS ECU detects the current draw anomaly and illuminates the EPS warning light (orange steering wheel icon). In early stages the fault is intermittent and heat-dependent; in later stages assist disappears entirely, leaving heavy manual steering. The column EPS motor is not individually serviceable in most workshops and the full EPS column assembly must be replaced. Labour for column removal and alignment check makes this a moderately expensive repair. Units from Japanese wreck yards are a common lower-cost solution but vary in remaining brush life.

Where to look: Steering column, EPS motor assembly behind dashboard lower panel

Parts involved: Steering rack.

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The ZGE20 Wish uses an electric motor-driven cable loop to power the rear sliding door on both driver and passenger sides. The steel drive cables run through a plastic conduit channel along the door sill and roof rail and are subject to repeated bending stress through thousands of open/close cycles. Individual wire strands fray progressively, causing increased motor current draw, intermittent door stall mid-travel, or complete cable break leaving the door immovable under power. A snapped cable can also jam the manual-release mechanism, trapping occupants.

Where to look: Rear sliding door cable conduit running along the lower sill and upper door track, motor mounted in the B-pillar or door panel depending on side

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The ZE20 Wish uses a column-mounted electric power steering (EPS) motor and reduction gear assembly. The worm gear coupling between the EPS motor and the steering column develops freeplay as the plastic gear teeth wear, producing a rattle or clunk felt and heard through the steering wheel when driving over minor road imperfections at low speed. In some cases the intermediate shaft universal joint within the column assembly also develops play, amplifying the symptom. The rattle is present regardless of steering wheel position but worsens on rough surfaces. Toyota Japan issued internal guidance on gear lash adjustment and replacement criteria.

Where to look: EPS motor worm reduction gear housing on upper steering column, cabin side of firewall

Parts involved: Steering rack.

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Wish power sliding door cables fray at guide pulleys causing slow or stuck door operation.

Where to look: Power sliding door mechanisms both sides

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The ANE11/ZNE10 Wish uses a column-assist electric power steering system where the motor drives a worm gear on the steering column. The rack-and-pinion itself sits on two rubber mount bushes bolted to the front subframe; these bushes deteriorate and allow the rack housing to shift under steering load, producing a knocking or rattling noise from the front of the cabin. A separate but concurrent failure involves wear in the column EPS motor coupling, which transmits a clunk or rattle through the steering wheel rim during low-speed parking manoeuvres; this can be misdiagnosed as a suspension fault. Both failures result in imprecise steering feel and customer-perceived safety concerns that require workshop diagnosis to isolate correctly.

Where to look: Steering rack mounted to front subframe below the engine bay; EPS motor and coupling on the steering column behind the dashboard

Parts involved: Steering rack.

Can't confirm for this car

The front suspension lower control arm on the ZGE20 Wish uses a press-fit ball joint that carries both the vertical load of the wheel and lateral cornering forces. The polyurethane boot seal degrades in NZ road conditions, admitting water and grit that erodes the ball stud taper and socket bearing surface. Once the joint develops play, caster and camber geometry deteriorates, causing accelerated tyre wear on the inner edge; in an advanced state the stud can pull out of the socket catastrophically, resulting in sudden loss of wheel alignment control.

Example of the part — not this vehicle

Where to look: Front suspension, lower control arm outboard end, connecting the arm to the steering knuckle on each side

Parts involved: Ball joint.

Can't confirm for this car

The ZGE20 Wish rear suspension uses a multi-link arrangement with multiple rubber-bonded bushes at each arm pivot point. The natural rubber compounds used in the OEM bushes undergo hydrolytic degradation and compression-set over time, particularly in the trailing arm and toe-control link mounts where cyclic torsional stress is highest. When the bushes collapse, rear toe and camber geometry shift outside specification, causing the vehicle to crab-walk, exhibit dart-and-weave behaviour on the motorway, and generate excessive rear tyre wear; the condition also shifts the brake balance rearward.

Where to look: Rear subframe and trailing arm pivot points, toe-control and camber link bush seats on both sides

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The Wish uses a multi-link rear independent suspension across both ZNE10 and ZGE20 generations. The trailing arm rubber bushes deteriorate with age and mileage, allowing the rear trailing arms to move outside their designed arc. This causes rear-end imprecision, rapid uneven tyre wear, and handling instability. Failure is progressive and often goes unnoticed until tyre wear becomes severe.

Where to look: Rear trailing arm mounting bushes at the sub-frame and arm junction, visible under the rear of the vehicle

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The front lower control arms on both ZE10 and ZE20 Wish models use rubber-bonded bushes at both the forward pivot and the rear subframe attachment point. The rear bush experiences combined torsional and lateral loading and typically fails first, with the rubber compound cracking and separating from its steel inner sleeve. The failure is accelerated by Australasian road conditions and is often not discovered until WOF inspection reveals excessive movement. A collapsed bush allows the front wheel camber and toe to shift under braking and cornering loads, causing the car to wander and pull unpredictably.

Example of the part — not this vehicle

Where to look: Front lower control arm rear pivot bush, both sides

Parts involved: Ball joint.

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Front lower arm ball joints wear causing clunking and handling imprecision.

Example of the part — not this vehicle

Where to look: Front lower suspension control arms

Parts involved: Ball joint.

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The front brake calipers on the ZGE20 Wish use sliding guide pins coated with grease and sealed by rubber dust boots to allow the caliper to float and maintain even pad-to-rotor contact on both sides. In NZ conditions, road salt, water ingress through deteriorated boots, and infrequent servicing cause the steel pins to corrode and seize within the aluminium caliper bracket bores. A seized guide pin prevents the outboard brake pad from fully releasing after brake application, causing the pad to drag continuously against the rotor and generating severe uneven pad wear, rotor scoring, and brake pull.

Where to look: Front brake assembly, guide pin bores in the caliper sliding bracket on each wheel

Parts involved: Brake disc and pads.

Can't confirm for this car

Both front and rear brake calipers on the ANE11/ZNE10 Wish use sliding guide pins to allow the caliper to float and apply even pad pressure across both disc faces. The guide pin boots are prone to splitting, admitting road salt moisture and brake dust that corrodes the pin bores; once the pins corrode in place the caliper can no longer centre itself, resulting in one pad dragging continuously against the rotor. This causes thermal overload on the affected corner, rapid and uneven pad consumption, rotor warping, and can ultimately cause brake fade or brake pull under heavy application; in NZ's coastal and wet road conditions this failure mode is considerably more common than in the vehicles' original Japanese domestic market environment.

Where to look: Caliper guide pin bores on both front and rear calipers at each wheel corner

Parts involved: Brake disc and pads.

Can't confirm for this car

The AZE10 Wish rear tailgate is held open by two gas struts that lose internal pressure with age, causing the tailgate to slowly drop or fall without warning once released. At minimum this is a repeated inconvenience when loading the boot; at worst the heavy glass-laden tailgate can fall rapidly causing head or arm injury to a person standing in the opening. The condition is near-universal on examples that have not had struts replaced, typically by 12 to 15 years of age. Replacement struts from OEM or quality aftermarket suppliers are widely available in NZ.

Where to look: Rear tailgate, one gas strut each side mounted between upper hatch frame and body

Parts involved: Shock absorber / strut.