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Lexus UX: M20A-FKS Cold-Start Timing Chain Rattle and Stretch

M20A-FKS Cold-Start Timing Chain Rattle and Stretch is a common engine fault on the Lexus UX on the 2018–2024 cars, and we rate it major. Putting it right costs $2,500 to $6,000 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 16 documented faults on the Lexus UX.

Vehicle
Lexus UX
Engine
M20A-FKS
Years
2018–2024
Fuel
petrol
Gearbox
cvt
System
Engine

This page covers the Lexus UX 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 UX faults16 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 2.0-litre M20A-FKS direct-injection petrol engine is susceptible to timing chain elongation and tensioner wear, producing a characteristic metallic rattle on cold start that typically subsides after 10-30 seconds of warm-up. The fault is accelerated by infrequent oil changes and short-trip driving that prevents full oil pressure build-up at start. Severe cases result in timing chain skip, causing misfires or catastrophic engine damage. Toyota/Lexus issued TSB EG-0152T covering related 2.0-litre TNGA engine timing chain tensioner updates.

What you would notice

  • Metallic rattling or clattering noise on cold start from the front of the engine
  • Rattle persists for 10-30 seconds before fading as oil pressure builds
  • Check engine light with cam-crank timing correlation codes P0016 or P0017
  • Rough idle or misfires on cold start in advanced cases
  • Visible oil sludge on dipstick or under oil filler cap indicating neglected servicing

How to check it

Where to look. Front of engine block, timing chain cover area

Cold-start the engine from fully cold and listen immediately for metallic rattling from the front of the engine lasting more than a few seconds. Check oil level and condition — dark sludgy oil indicates neglect that worsens chain wear. Request full service history to verify regular oil changes at or before 10,000 km intervals. If a workshop inspection is possible: On a scan tool check for P0016 or P0017 cam/crank correlation codes.

Parts involved: Timing chain.

What it costs to put right

$2,500 to $6,000 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

  • “Can you show me full dealer or workshop service records confirming oil changes at or below 10,000 km intervals?”
  • “Has the vehicle ever had a check engine light for cam or crank timing faults?”
  • “Has the car primarily been used for short trips under 10 km?”

Now check the Lexus UX 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 UX buyer questions

Is m20a-fks cold-start timing chain rattle and stretch serious on a Lexus UX?

We rate it major and common on the Lexus UX. The 2.0-litre M20A-FKS direct-injection petrol engine is susceptible to timing chain elongation and tensioner wear, producing a characteristic metallic rattle on cold start that typically subsides after 10-30 seconds of warm-up. The fault is accelerated by infrequent oil changes and short-trip driving that prevents full oil pressure build-up at start. Severe cases result in timing chain skip, causing misfires or catastrophic engine damage. Toyota/Lexus issued TSB EG-0152T covering related 2.0-litre TNGA engine timing chain tensioner updates.

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

$2,500 to $6,000 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 UX years are affected?

Our research records this fault on the 2018–2024 Lexus UX. 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 from fully cold and listen immediately for metallic rattling from the front of the engine lasting more than a few seconds. Check oil level and condition — dark sludgy oil indicates neglect that worsens chain wear. Request full service history to verify regular oil changes at or before 10,000 km intervals. If a workshop inspection is possible: On a scan tool check for P0016 or P0017 cam/crank correlation codes. Look here: Front of engine block, timing chain cover area