Toyota Isis: common faults & what to check

Which Toyota Isis are you looking at?

2 generation variants documented. Pick the shape you recognise: the faults, the servicing and the timeline below all narrow to it. Free, no account needed.

Petrol

2 variants documented

2004–2017AM102004–2017AM101.8 petrolPetrolDocumented issues5 knownSee faults & what to checkPhoto: User3204 via Wikimedia Commons, CC BY-SA 4.0.

2004–2017AM102004–2017AM102.0 petrolPetrolDocumented issues9 knownSee faults & what to checkPhoto: User3204 via Wikimedia Commons, CC BY-SA 4.0.

Now narrow it to the engine

A 1.8 and a 2.4 of the same car do not fail the same way, so the faults below narrow to the engine as well as the year. Free, no account needed.

Start your free check on this Toyota Isis

No plate needed. You get the risk score, the buyer's checklist and the guided inspection for the exact car you picked above — not the whole nameplate.

The checks worth doing on a Toyota Isis before you hand over any money. Every documented fault is listed below, each with its own page.

• Costly issue

  Carbon deposits appear as rough, dark-grey crust.

  See why

  1AZ-FSE D-4 Intake Valve Carbon Buildup

  The 1AZ-FSE uses Toyota D-4 gasoline direct injection, which means fuel is injected directly into the cylinder rather than the intake port. Without fuel washing the back of the intake valves, combustion blow-by gases deposit hard carbon on the valve faces and stems over time. Deposits of 2-4 mm thickness are typical above 80,000 km. Affected valves cannot seal fully when cold, causing a lumpy or misfiring idle that clears once the engine reaches operating temperature as thermal expansion partially compensates. Symptoms worsen progressively with mileage. Remediation requires mechanical walnut-shell blasting or manual scraping after intake manifold removal; chemical top-end additives cannot dislodge baked-on deposits on a GDI engine.

  What you would notice

  • Rough or lumpy idle when cold, smoothing out after 3-5 minutes of warm-up
  • Intermittent misfire codes P030x on cold start
  • Hesitation or stumble under light throttle below 2000 rpm
  • Slightly elevated cold-start fuel consumption

  Typically $450–$950 to put right.

• Costly issue

  Road test on a flat road at constant light throttle between 30-50 km/h to reproduce judder.

  See why

  K311 CVT Belt Judder Under Light Throttle

  The Toyota K311 chain-belt CVT fitted to the Isis ANZ10 and ANZ11 exhibits a characteristic shudder or judder under gentle, steady-state throttle inputs at low to medium speeds, typically between 20-60 km/h. The judder is caused by micro-slip between the steel push-belt and the primary and secondary pulley faces when CVT fluid friction-modifier additives degrade. In early stages the symptom is intermittent and may disappear after fluid reaches operating temperature. As the unit ages, shudder becomes constant and is accompanied by slight hesitation. Continued operation accelerates belt and pulley face wear, eventually requiring a full CVT rebuild or replacement. Toyota specified a dedicated CVTF fluid; substituting generic ATF greatly accelerates degradation. Many grey imports arrive with unknown CVT service history.

  What you would notice

  • Vibration or shudder felt through drivetrain under light steady throttle at 20-60 km/h
  • Judder disappears at full throttle or when coasting
  • Slight hesitation accompanying the shudder sensation
  • Shudder more pronounced when CVT fluid is cold or degraded

  Typically $200–$6,800 to put right.

• Costly issue

  Check oil level and note date of last top-up relative to mileage driven.

  See why

  1AZ-FSE Excessive Oil Consumption via Worn Piston Rings

  The 1AZ-FSE engine has a documented history of accelerated piston ring wear at higher mileages, typically becoming apparent beyond 120,000 km. The compression and oil-control rings lose their face tension, allowing engine oil to be drawn past the rings into the combustion chamber where it burns and exits through the exhaust. Consumption rates of 0.5-1.5 litres per 1,000 km are reported on high-mileage examples. Blue-tinged exhaust smoke on acceleration and deceleration is the primary symptom. Toyota released extended warranty provisions in Japan for this fault on 1AZ-FSE engines. Many NZ grey imports arrive with high odometer readings, making this a significant risk. Confirmation requires a compression test plus a leak-down test; oil-consumption monitoring over a known distance is definitive.

  What you would notice

  • Blue or blue-grey exhaust smoke on acceleration and engine braking
  • Oil level dropping more than 0.5 L per 1,000 km
  • Fouled spark plugs with oily deposits
  • Slight burning oil smell from exhaust at operating temperature

  Typically $2,800–$6,500 to put right.

• Costly issue

  Perform a cold start with the bonnet open and listen for timing chain rattle from the front-right of the engine near the timing cover.

  See why

  1ZZ-FE Timing Chain Tensioner Cold-Start Rattle

  The 1ZZ-FE 1.8-litre engine in the ANZ11 Isis uses a single-row timing chain with a hydraulic tensioner. The tensioner relies on oil pressure to maintain chain tension; at cold start, oil takes several seconds to fully pressurize the tensioner piston. On worn tensioners or engines with infrequent oil changes, the chain slackens during this low-pressure window and rattles against the timing chain guide and cover. The rattle is a loud metallic chattering sound lasting 2-10 seconds from cold, then disappearing once oil pressure builds. Prolonged operation with a failing tensioner can cause accelerated chain stretch, guide rail wear, and ultimately timing chain skip, which risks valve-to-piston contact. Toyota issued a TSB for 1ZZ-FE tensioner replacement and specified 5W-30 oil to aid faster cold pressurisation.

  What you would notice

  • Loud metallic rattling from timing cover for 2-10 seconds on cold start
  • Rattle absent once engine reaches operating temperature
  • Possible stored code P0016 camshaft-crankshaft correlation if chain has stretched
  • Increased rattle duration as fault progresses

  Typically $550–$1,400 to put right.

• Costly issue

  Operate every sliding door several times from both the key/remote and the inside buttons.

  See why

  Power sliding door(s) motor / latch failure

  The Isis's powered sliding rear doors are a common trouble spot: the door may refuse to open or close, work intermittently, or need several tries. It can be the drive motor, the small release/latch motor, worn rollers or a tired sensor. It's a family-carrying feature, so a door that won't operate is a real inconvenience — check every door works every time.

  What you would notice

  • Power door won't open or close on the button
  • Door opens/closes intermittently or part-way
  • Grinding or straining noise from the door mechanism

  Typically $400–$1,200 to put right.

• Costly issue

  Cycle the power sliding door fully open and closed at least five times and observe for any mid-travel stall or reversal.

  See why

  Power Sliding Door Motor Cable Fraying — Door Stops Mid-Travel

  The ANZ10 Isis power sliding door system uses a drum-and-cable mechanism driven by an electric motor mounted in the door B-pillar or behind the trim panel. The stainless-steel actuator cable is routed around several pulleys and is subject to repetitive bending stress through hundreds of thousands of open-close cycles. From approximately 100,000-120,000 km onward, individual cable strands begin fraying at the sharpest pulley contact points. As the frayed section thickens, it creates increased drag, causing the door motor controller to detect an obstruction and halt door travel mid-swing. In advanced cases the cable snaps entirely, leaving the door inoperative in the open or partially open position. The door motor itself can also seize if run under sustained high load from a fraying cable. Replacement requires B-pillar trim removal and cable re-routing.

  What you would notice

  • Power sliding door stops and reverses direction mid-travel without obstruction
  • Door operation becomes intermittent, sometimes working and sometimes stopping
  • Unusual grinding or clicking noise from door B-pillar area during operation
  • Door completely inoperative in open position if cable snaps

  Typically $350–$950 to put right.

Toyota Isis service schedule

What falls due, and at what distance, for each generation of the Toyota Isis. These are the model’s intervals — the car’s own service book is the only thing that can tell you what has actually been done to it.

What these repairs cost on other cars

Some of the Toyota Isis’s documented faults are repairs other models share. Each page lists the documented NZ cost for every model it affects.

• Timing Chain Replacement Cost
• CVT Gearbox Repair Cost

Other Toyota models