Thinking about buying a used Toyota Isis (2004–2017) in New Zealand? We've documented 11 known faults for this model spanning transmission, engine, body & rust, and electrical. Each researched and verified before it's published. The most serious issues here are rated major. Two are set out in full below — the rest, with the symptoms, repair costs and checks for each, are free with an account.
11
Documented faults
Major
Most serious
$400–$1,200
Typical repair
4
Systems covered
Known Toyota Isis faults
Every fault below is documented specifically for this model — researched and verified before it’s published.
01K311 CVT Belt Judder Under Light Throttle
MajorCommonTransmission $200–$6,800 to fix
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.
Symptoms to 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
What to check
Road test on a flat road at constant light throttle between 30-50 km/h to reproduce judder. Check CVT fluid condition via dipstick or drain plug: fluid should be pink-red and odourless; dark brown or burnt-smelling fluid indicates neglect. Confirm fluid type matches Toyota CVTF specification. Inspect for any CVT fault codes. Note whether shudder is intermittent (early stage) or constant (advanced wear).
Where to look: K311 CVT unit, located in the transaxle housing below and forward of the engine
Ask the seller
“When was the CVT fluid last changed, and what fluid type was used?”
“Has the car ever exhibited a shudder or vibration when driving at steady low speed?”
“Is there any CVT service or rebuild history?”
02Throttle Body Carbon Buildup Causing Idle Hunt
MinorCommonEngine $180–$480 to fix
The Toyota Isis ANM10 uses the 1AZ-FSE (2.0L D4 direct injection) or 1NZ-FE (1.5L) engines. In direct-injection variants, oil vapour from the PCV system deposits carbon on the throttle bore and throttle plate because — unlike port injection — there is no fuel washing the intake tract. Over time the carbon reduces the effective throttle opening at idle, causing the idle air control system to hunt between high and low RPM as it tries to compensate. The throttle body's integrated position sensor also reads inconsistently when the bore is heavily fouled, logging throttle position codes and triggering check engine lights. Intake manifold runners and EGR passages compound the problem by recirculating exhaust soot. Chemical walnut-blast cleaning or physical throttle body removal and cleaning resolves the symptom; cleaning intervals of 60,000–80,000 km are recommended preventively.
Symptoms to notice
Idle fluctuates between 500 and 1200 RPM (hunting)
Rough idle particularly when cold or just warmed up
Check engine light with throttle position or idle control codes
Hesitation on light throttle from rest
Poor fuel economy at city speeds
What to check
Start the engine cold and observe idle quality for the first two minutes. A healthy engine should settle to a stable idle within 30 seconds of start. Rev the engine lightly and release; idle should return smoothly. Inspect throttle bore visually with a torch if access allows. If a workshop inspection is possible: If possible, use OBD-II to monitor live throttle position and idle air control data for erratic readings.
Where to look: Throttle body on intake manifold, top-centre of engine
Ask the seller
“Has the throttle body ever been cleaned?”
“Does the idle ever feel rough or fluctuating?”
“Has the check engine light appeared with idle or throttle-related codes?”
EngineMajor
EngineMajor
Body & RustMajor
EngineMajor
ElectricalMajor
EngineMajor
ElectricalMajor
EngineMajor
EngineMajor
9 more documented faults on the Toyota Isis
Symptoms, what to check, where to look and what to ask the seller — for every fault above. Free with an account, no card needed. One account covers one vehicle, so make it the car you’re actually looking at.
This page covers the model. Enter the plate of the actual car you’re looking at and see its year, engine, safety rating and register flags — free, no account needed.
Like any used car, it depends on the specific example and its service history. Across the 11 documented faults for the Toyota Isis, the recurring problem areas are transmission, engine, and body & rust. A Toyota Isis with a full service history and no signs of the issues listed on this page can be a sound buy but each one needs to be checked individually before you commit.
What are the most common problems with a used Toyota Isis?
+
We've catalogued 11 known faults for the Toyota Isis, covering transmission, engine, and body & rust. Two are written out in full on this page. The rest — with the symptoms to notice, what to inspect, and typical repair costs for each — are free once you create an account.
How much do repairs cost on a Toyota Isis?
+
Most single repairs on the Toyota Isis fall between $400–$1,200 at NZ independent-workshop rates. Some of the 11 documented faults cost less and a few cost considerably more, and no one car needs them all. Knowing which ones to look for before you view is what lets you negotiate the price down or walk away.
Should I get a pre-purchase inspection on a Toyota Isis?
+
Yes. A Toyota Isis inspection focused on its known weak points is the single best way to avoid an expensive mistake. KickTyres gives you a guided, model-specific inspection plus a market valuation and negotiation figure for $17.90 far less than the cost of missing one of the faults on this page.