Toyota Noah: common faults & what to check

Symptoms to notice

• P0A93 (Inverter Cooling System Performance) or P0A94 fault code stored
• Hybrid system warning triangle illuminated
• Audible grinding or absence of expected pump hum from engine bay on start-up
• Inverter coolant reservoir level drops over time with no external leak
• Vehicle enters reduced-power mode or shuts down hybrid drive under sustained acceleration

What to check

With the engine warm, listen for a faint whirring from the inverter coolant pump near the front-left of the engine bay. Check the inverter coolant reservoir (separate small tank, usually near the strut tower) for correct level and absence of rust-coloured contamination indicating pump seal wear. If a workshop inspection is possible: An OBD scanner should show no P0A93 or P0A94 codes.

Symptoms to notice

• Shudder or vibration felt through the cabin under light throttle between 30–60 km/h
• Hesitation or jerk on acceleration from a rolling stop
• Whining or humming noise from the transmission that changes with road speed
• Delayed engagement when selecting Drive from Park
• Dark brown CVT fluid on inspection indicating additive breakdown

What to check

1. 1.During the test drive, accelerate gently from 20–50 km/h and feel for a rhythmic shudder or vibration through the drivetrain distinct from engine vibration.
2. 2.Ask to drain a small CVT fluid sample: it should be bright red or pink; dark brown or black fluid with a burnt smell indicates severe degradation.
3. 3.Confirm service history includes CVT fluid changes; many grey imports arrive in NZ with no CVT service record.

Symptoms to notice

• Unstable or fluctuating idle, especially on cold start
• P0011 (camshaft timing over-advanced) or Valvematic system DTCs
• Reduced power output and sluggish throttle response
• Rattle or knocking from the valve cover area at idle
• Increased fuel consumption without other apparent cause

What to check

Cold-start the engine and monitor idle quality for the first 60–90 seconds: a stumbling, hunting or surging idle is the earliest indicator. Scan for codes P0011, P0021, or Valvematic-specific Toyota codes (P1349). Physically inspect the Valvematic actuator housing on the left side of the cylinder head for oil seepage, and ask whether 0W-20 Toyota-specified oil has been used consistently.

Symptoms to notice

• Oil level dropping significantly between service intervals requiring mid-interval top-ups
• Blue-grey smoke from exhaust on startup or under hard acceleration
• Oil-fouled spark plugs on inspection
• Low oil warning light appearing before the next scheduled service
• Carbon deposits visible inside exhaust tip

What to check

1. 1.Check oil level on dipstick and ask when it was last topped up.
2. 2.Observe exhaust during cold start and under brisk acceleration for blue smoke.
3. 3.Inspect spark plugs for oil fouling if accessible.
4. 4.Request full oil service history to identify whether intervals have been shortened to compensate.

Symptoms to notice

• Rhythmic shudder or vibration felt through the floor and seat under gentle acceleration at low to moderate speeds
• Condition improves or disappears at higher throttle openings or highway speeds
• Hesitation or brief loss of drive during the judder event before the transmission catches up
• CVT fluid that is dark brown, smells burnt, or has visible contamination on the dipstick

What to check

1. 1.Test-drive at light throttle between 30 and 60 km/h on a flat road and note any rhythmic shudder or vibration through the floor.
2. 2.Check CVT fluid condition on the dipstick: fluid should be clear pink-red; brown or dark fluid with a burnt smell indicates overheating or advanced degradation.
3. 3.Ask for the CVT fluid service history; Toyota specifies genuine Toyota CVT fluid (TC) only.

Symptoms to notice

• Cold-start rattling from front of engine that disappears within 30 seconds of oil pressure build-up
• Check engine light with camshaft position or VVT timing codes
• Rough idle during warm-up phase
• Increasing rattle duration on cold starts as the fault progresses

What to check

Cold-start the engine and listen for 5 to 10 seconds for chain rattle from the timing cover at the front of the engine before oil pressure builds. Any rattle lasting more than a few seconds is a warning sign. Scan for camshaft timing, VVT, or crankshaft correlation codes. Request full service history to verify oil changes at intervals no longer than 10,000 km. Risk is highest above 150,000 km with an incomplete history.

Symptoms to notice

• Hard hot-start requiring extended cranking
• Rough idle and engine stumble under load
• Hesitation on acceleration from low speed
• DTC P0087 (fuel rail or system pressure too low)

What to check

1. 1.Request a fuel rail pressure test; pressure below specification at idle or under acceleration confirms pump wear.
2. 2.Check for stored DTCs relating to fuel system pressure or rail pressure sensor.
3. 3.Inspect fuel filter and quality.
4. 4.The HPFP on the AZR60G is a known failure part with replacement units widely listed for this specific chassis code.

Symptoms to notice

• Rough or lumpy idle that worsens when the engine is cold
• Hesitation or stumble under light throttle acceleration
• Persistent misfire fault codes (P0300–P0304) with no ignition or fuel system cause found
• Reduced fuel economy compared to the engine's rated consumption

What to check

1. 1.Check for rough idle, misfire DTCs (P0300-P0304), and smoke at idle.
2. 2.Request any history of walnut blasting or chemical intake cleaning.
3. 3.If a workshop inspection is possible: Remove the intake ducting and use a borescope or mirror to view the back of the intake valves through the inlet ports; look for grey-black crusty buildup.

Symptoms to notice

• Blue-grey smoke from exhaust on cold startup, clearing within 30–60 seconds of running
• Blue smoke visible in the rearview mirror when lifting off throttle at highway speed
• Engine oil level 1–2 litres low between 5,000 km service intervals with no external leaks
• Spark plugs showing black, oily fouling on tip and electrode

What to check

1. 1.Check engine oil level — low level relative to recent top-up interval is a red flag.
2. 2.Start cold engine and observe exhaust for blue smoke on initial start and during first 30 seconds of running.
3. 3.Road test: lift off throttle from 80 km/h and watch exhaust for blue puff as engine braking begins.
4. 4.Inspect spark plugs for oil fouling (black oily deposits on electrode).
5. 5.Ask seller how often oil needs to be topped up between service intervals.

Symptoms to notice

• Knocking / clunking noise from the front when pulling away from a stop
• Clunk felt or heard when coming to a stop or during low-speed manoeuvres
• Noise more noticeable on light throttle take-up or when turning at low speed
• Repetitive 'kon-kon' or 'kotsu-kotsu' sound rather than a continuous whine

What to check

1. 1.Drive the car slowly from a standstill in a quiet area, both straight and on gentle turns, and listen for a knock or clunk from the front driveshaft area as drive takes up; repeat gently braking to a stop.
2. 2.Under the car, inspect both front CV-axle boots for splits or grease throw and check for play in the shafts.
3. 3.Ask for service history showing whether a driveshaft has already been replaced.

Symptoms to notice

• Petrol smell detectable on the oil dipstick
• Oil level rising above the maximum mark without any top-ups
• Thin or watery oil texture on the dipstick
• Increased engine wear if not addressed by shortened service intervals

What to check

1. 1.Pull the dipstick and smell for fuel contamination — oil should smell like oil, not petrol.
2. 2.Check whether the oil level reads above maximum without any top-ups having been performed.
3. 3.Review service records for oil change intervals; vehicles used for short trips should show intervals shorter than 5,000 km.
4. 4.Cold-start a known history vehicle and check for excessive white or rich exhaust smoke.

Symptoms to notice

• The K112 CVT fitted to ZRR70 Noah develops shudder and slip as the belt surface wears.
• Confirm with pre-purchase inspection by a qualified mechanic

What to check

The K112 CVT fitted to ZRR70 Noah develops shudder and slip as the belt surface wears.

Symptoms to notice

• Idle RPM hunting or fluctuating between 600 and 1,000 rpm when warm
• Hesitation or stumble on light throttle from standstill
• Rough idle that improves after the engine reaches full operating temperature
• Slight increase in fuel consumption without other mechanical cause
• Occasional rough cold-start idle settling within 30–60 seconds

What to check

With the engine warm and at idle, observe the tachometer for hunting or fluctuating RPM between 600–900 rpm. Also check whether the idle stabilises after a light rev to 2,500 rpm, which temporarily clears deposits. If a workshop inspection is possible: Remove the air intake hose at the throttle body to inspect the throttle plate for thick black carbon deposits — some light coating is normal, heavy build-up above 2mm indicates neglect.

Symptoms to notice

• Persistent P3000 or P3011–P3019 battery fault codes on OBD scan
• Fuel economy noticeably worse than rated 23–26 km/L combined
• Hybrid battery gauge swings rapidly or shows perpetually low charge
• EV-only mode unavailable at low urban speeds
• Triangle warning lamp and master warning illuminate on dash

What to check

1. 1.Request a hybrid battery state-of-health scan showing individual cell voltages and capacity percentage.
2. 2.On a test drive, watch for the hybrid battery gauge cycling rapidly between full and empty, or the combustion engine failing to shut off at low speeds where EV-only mode should engage.
3. 3.Check the battery cooling fan behind the rear seat for dust blockage.

Symptoms to notice

• Hybrid system warning light or Check Hybrid System message on dash
• Fuel economy noticeably below factory specification
• HV battery state-of-charge dropping faster than normal between journeys
• DTCs P3000 or block-specific codes P3020 through P3027

What to check

Physically inspect the HV battery cooling fan filter located at the base of the rear seat or B-pillar — heavy clogging indicates the battery has been running hot. Request battery balance test data showing voltage spread across all modules under load; a spread greater than 0.3 V across blocks indicates a failing pack. Confirm the 12 V auxiliary battery is healthy as a weak 12 V battery can trigger false P3000 codes. If a workshop inspection is possible: Scan all hybrid-specific fault codes using a Toyota-compatible tool rather than a generic OBD-II reader.

Symptoms to notice

• Red hybrid system warning triangle on dashboard, sometimes with reduced power mode engaged
• Fuel economy noticeably worse than expected — hybrid not deploying EV assist at low speeds
• Cooling fan audible at high speed from rear of cabin in warm weather, even at rest
• Hybrid battery state-of-charge gauge fluctuating rapidly or not charging to full during regenerative braking

What to check

1. 1.Start the vehicle and place your hand near the duct exhaust outlet (typically near the C-pillar trim): you should feel airflow.
2. 2.Check dashboard for any red or amber hybrid system warning icons.
3. 3.A cell voltage spread greater than 0.3V at rest indicates degradation.
4. 4.If a workshop inspection is possible: Use a scan tool capable of reading hybrid battery data (Toyota Techstream or equivalent) to view cell voltage spread and battery temperature values.
5. 5.Lift the rear seat cushion and inspect the battery cooling intake grille — it should be clear of lint and debris.

Symptoms to notice

• Power sliding door stops or reverses partway through its travel without any obstruction
• Grinding or clicking sound from inside the door rail when the door operates
• Door motor audible but door does not move when the open or close button is pressed
• Door fails to achieve a firm latch and can be pushed open easily from outside

What to check

1. 1.Operate both sliding doors through several full open-close cycles and listen for grinding, clicking, or the motor running with no door movement.
2. 2.Inspect the lower rail for frayed wire strands or rust.
3. 3.Check that the door latches firmly at both the half-latch and full-latch positions.
4. 4.Pull gently on a fully closed door to confirm it does not rattle or move.

Symptoms to notice

• Touchscreen freezes or reboots on its own
• Screen stays on / does not switch off after the car is turned off
• Bluetooth or Apple CarPlay / Android Auto disconnects or fails to pair
• Laggy or unresponsive touch input
• Video or TV image remaining on screen while driving (pre-fix cars)

What to check

On a test drive confirm the head unit boots promptly, the touchscreen responds without lag, Bluetooth pairs to your phone, and the screen powers off when the ignition is switched off. Ask whether the April 2022 display-audio improvement measure / software update has been applied and check for any pending software updates in the settings menu.

Symptoms to notice

• Clunking or knocking from the front suspension when driving over speed bumps, potholes, or rough road surfaces
• Vague or wandering steering with increased effort needed to maintain a straight line
• Uneven front tyre wear, particularly on the inner edge, caused by altered camber from a loose joint
• Visible torn or grease-contaminated dust boot on the lower ball joint during a visual inspection

What to check

Inspect the rubber dust boot for cracks, tears, or grease leakage. On a test drive, note any clunking over bumps or vagueness in straight-line steering that could indicate joint play under load. If a workshop inspection is possible: With the front of the vehicle safely supported on stands, grip the tyre at 12 and 6 o'clock and attempt to rock it; any detectable clunking or vertical play indicates ball joint wear.

Symptoms to notice

• Rust bubbles or blistering on painted sill or lower door edge
• Soft spots or perforations in floor pan discovered under carpet
• Rust staining in rear wheel arches or spare tyre well
• Flaking or bubbling undercoating at suspension mounting points

What to check

1. 1.Lift all floor carpets and inspect the floor pan directly, focusing on the centre tunnel, under second and third row seats, and the rear load area.
2. 2.Probe all four inner sills firmly with a screwdriver to detect structural rust behind the paintwork.
3. 3.Inspect both rear wheel arch lips and the spare tyre recess.
4. 4.Check the sub-frame mounting reinforcements for flaking undercoating.
5. 5.If a workshop inspection is possible: Lift the vehicle on a hoist for a full underbody inspection — a roadworthy check alone is insufficient to identify hidden rust.

Symptoms to notice

• Clunking or thumping from the front suspension over bumps, speed humps, or sharp road edges
• Front end vagueness or wandering on straight roads, requiring constant small steering corrections
• Uneven front tyre wear — excessive wear on inside or outside shoulder despite recent alignment
• Vehicle pulling to one side under firm braking from highway speed

What to check

Visually inspect the rubber bush material: cracking, splitting, or visible voids in the rubber are rejection criteria. Check for fresh alignment report — if caster or camber is out of specification and the vehicle has new tyres, suspect bush wear preventing correct geometry. Drive over a sharp bump at low speed and listen for a thud or double-knock from the front. If a workshop inspection is possible: With the vehicle on a hoist, grasp each front lower arm and attempt to move it vertically and rearward — any movement beyond 1–2 mm indicates bush wear.

Symptoms to notice

• Vehicle pulls to one side during braking, requiring the driver to correct the steering
• One wheel significantly hotter than its counterpart after normal driving, detectable by carefully feeling the wheel rim
• Uneven brake pad wear with the outer pad worn much thinner than the inner pad on the same caliper
• Grinding or squealing noise from one wheel even when the brake pedal is not applied, caused by a dragging pad

What to check

After a test drive of moderate length, carefully feel each wheel rim near the hub for unusual heat; a seized caliper will make one wheel noticeably hotter than its opposite. Inspect the guide pin dust boots for cracking or missing sections. Check pad thickness on both sides of each caliper; a significant difference between inner and outer pad thickness confirms caliper drag. If a workshop inspection is possible: Remove the wheels and attempt to slide each caliper by hand on its guide pins—it should move freely with light finger pressure.

Symptoms to notice

• Clunking or rattling noise from the steering rack area when driving over potholes or road joints
• Knock felt through the steering wheel rim when hitting a bump while cornering
• Loose or notchy feeling on-centre in the steering with slight free play before effort builds
• Intermittent EPS warning light (orange steering wheel icon) during cold weather starts

What to check

1. 1.Drive slowly over a speed bump or rough road surface and listen for a knock or rattle that coincides with steering wheel vibration.
2. 2.With the vehicle stationary, have a second person sharply turn the wheel left and right while you listen under the bonnet for clunking from the rack or intermediate shaft.
3. 3.Check for free play in the steering by gently rocking the wheel left and right — more than 10 mm of play at the rim before the rack moves indicates internal wear.
4. 4.Inspect tie-rod ends for play by gripping and attempting to move them with the wheel straight.

Symptoms to notice

• Rear tailgate stiff or creaking when opening, requiring increasing force over time
• Visible orange rust on hinge pin barrels or around hinge mounting plates at roofline
• Paint bubbling or blistering on body panel adjacent to upper tailgate hinges
• Tailgate fails to latch fully or sits proud of body line on one side after forced opening

What to check

Open and close the rear tailgate several times, noting smoothness — any resistance, creaking, or stiffness indicates hinge corrosion. With tailgate open, inspect both hinge barrels and pins visually for surface rust, pitting, or seized movement. Check the hinge mounting plates on the body for bubbling paint or rust bleed, which indicates corrosion spreading behind the plate. Close the tailgate and inspect the seal line for even gap — a hinge that has shifted under corrosion load will show uneven gap or a misaligned lock latch.