Skip to content
KickTyres
MajorCommonEngine

Lexus NX: 8AR-FTS Timing Chain Tensioner Cold Rattle

8AR-FTS Timing Chain Tensioner Cold Rattle is a common engine fault on the Lexus NX on the 2014–2021 cars, and we rate it major. Putting it right costs $900 to $3,500 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 22 documented faults on the Lexus NX.

Vehicle
Lexus NX
Engine
8AR-FTS
Years
2014–2021
Fuel
petrol
Gearbox
auto
System
Engine

This page covers the Lexus NX as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Lexus NX faults22 documented faults on this model

What you are looking at

The front of a dual overhead camshaft engine with the timing cover removed, exposing the timing chain and sprockets.Example of the part — not this vehicle

The front of a twin-cam engine with the timing cover off — chain, sprockets and guides.

Logansenf · CC BY-SA 4.0 · Wikimedia Commons

What goes wrong

The 8AR-FTS 2.0T turbocharged engine fitted to AGZ10/AGZ15 NX models is prone to timing chain tensioner hydraulic pressure loss after extended cold soak. On cold starts, especially below 10 degrees C, the tensioner takes 2-5 seconds to build oil pressure, allowing the chain to slap against the upper timing cover. Repeated episodes accelerate guide and ratchet wear. Neglected cases progress to chain stretch and timing deviation requiring full chain set replacement. Toyota issued TSBs addressing revised tensioner designs and improved ratchet mechanisms.

What you would notice

  • Rattling or chattering from engine front on cold start, disappearing within 5-10 seconds
  • Noise more pronounced in winter or after overnight cold soak
  • P0016 or P0017 cam/crank correlation fault codes in advanced cases
  • Rough idle or hesitation on cold start in severe cases

How to check it

Where to look. Engine front timing cover, upper timing chain tensioner and guide assembly

Cold-start the engine and listen carefully at the front timing cover for rattle duration. Gently rev the engine and note if noise persists beyond 10 seconds. Request scan tool readout for any stored P001x timing codes. Check oil change service history as extended intervals accelerate tensioner wear.

Parts involved: Timing chain.

What it costs to put right

$900 to $3,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

  • “Has the timing chain tensioner ever been replaced or inspected?”
  • “What has been the oil change interval and which oil weight is used?”
  • “Has any cold-start rattle been noticed, particularly in winter?”
  • “Are there any stored engine fault codes related to cam or crank timing?”

Now check the Lexus NX you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Lexus NX buyer questions

Is 8ar-fts timing chain tensioner cold rattle serious on a Lexus NX?

We rate it major and common on the Lexus NX. The 8AR-FTS 2.0T turbocharged engine fitted to AGZ10/AGZ15 NX models is prone to timing chain tensioner hydraulic pressure loss after extended cold soak. On cold starts, especially below 10 degrees C, the tensioner takes 2-5 seconds to build oil pressure, allowing the chain to slap against the upper timing cover. Repeated episodes accelerate guide and ratchet wear. Neglected cases progress to chain stretch and timing deviation requiring full chain set replacement. Toyota issued TSBs addressing revised tensioner designs and improved ratchet mechanisms.

How much does it cost to fix on a Lexus NX?

$900 to $3,500 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Lexus NX years are affected?

Our research records this fault on the 2014–2021 Lexus NX. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Cold-start the engine and listen carefully at the front timing cover for rattle duration. Gently rev the engine and note if noise persists beyond 10 seconds. Request scan tool readout for any stored P001x timing codes. Check oil change service history as extended intervals accelerate tensioner wear. Look here: Engine front timing cover, upper timing chain tensioner and guide assembly