Lexus Ls400 MOT Failures
An analysis of 19,492 real DVSA MOT tests on the Lexus Ls400 — what fails, how often, and how that compares to every other car on UK roads. Generations covered: UCF10 (1990–1994), UCF20 (1995–2000).
Where the Lexus Ls400 fails its MOT
The single biggest MOT failure point on the Lexus Ls400 is power steering fault — this model is 25 times more likely to fail on this item than the average car on UK roads. That makes it a significant weak point for anyone buying or owning this model. Across 19,492 MOT tests, 6.33% of all Lexus Ls400 tests recorded this as a failure.
Steering faults include worn track rod ends, power steering leaks, and rack wear. These are safety-critical — any play in the steering should be investigated immediately.
Other notable weak points include emissions failure (14x the fleet average), structural corrosion (11x the fleet average), suspension pin, bush or joint worn (29x the fleet average), and subframe bushes or mounts worn (9.1x the fleet average). These ratios compare the Lexus Ls400's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 4 categories: Steering, Exhaust & Emissions, Bodywork, Suspension. If you're inspecting a Lexus Ls400 before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Lexus Ls400's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Lexus Ls400 specifically, the DVSA data shows the most common failures at this mileage are suspension pin, bush or joint worn (29x the average) and power steering fault (25x). structural corrosion (9.3x) and track rod ends worn (5.3x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Lexus Ls400 specifically, the DVSA data shows the most common failures at this mileage are power steering fault (18x the average) and fluid leak (13x). exhaust system damage (11x) and structural corrosion (11x) also appear frequently.
The shift from suspension pin, bush or joint worn at lower mileages to power steering fault at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Lexus Ls400 specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Vehicle structure corrosion reducing assembly rigidity Dangerous
The LS400 suffers from significant structural corrosion that reduces the rigidity of the vehicle assembly, particularly around suspension mounting points and the rear subframe area. Affects UCF10, UCF20; typical independent garage repair cost is £1,500–£4,000.
Suspension mounting point corrosion Dangerous
Corrosion around suspension mounting points represents a critical safety issue on the LS400, with the load-bearing structure within 30cm of suspension component mountings deteriorating significantly above fleet average rates. Affects UCF10, UCF20; typical independent garage repair cost is £2,000–£5,000.
Power steering system fluid leaks and pump failure Major
The LS400 has a documented pattern of power steering system failures, with the hydraulic pump and associated seals failing at significantly higher rates than the fleet average. Affects UCF10, UCF20; typical independent garage repair cost is £400–£800.
Suspension bushes and joint excessive wear Major
The LS400 suffers from accelerated wear of suspension bushes and joints, failing at 7.6 times the fleet average rate. Affects UCF10, UCF20; typical independent garage repair cost is £400–£800.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Lexus Ls400 common problems breakdown.
What to check before buying a Lexus Ls400
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Lexus Ls400:
Steering — check for power steering fault, track rod ends worn. Exhaust & Emissions — check for emissions failure, fluid leak. Bodywork — check for structural corrosion, exhaust system damage. Suspension — check for suspension pin, bush or joint worn, subframe bushes or mounts worn.
Beyond the MOT items, ask specifically about vehicle structure corrosion reducing assembly rigidity and suspension mounting point corrosion. These won't show up on a standard MOT but can be expensive to fix — repairs start from £1,500. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Lexus Ls400?
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Lexus Ls400 MOT FAQs
What are the most common MOT failures on a Lexus Ls400?
Based on 19,492 DVSA MOT tests, the most common failure is power steering fault — at 25x the national fleet average. Other frequent failures include emissions failure and structural corrosion.
Is the Lexus Ls400 reliable based on MOT data?
The Lexus Ls400 has 9 MOT failure categories above the fleet average. Specialists also flag vehicle structure corrosion reducing assembly rigidity as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Lexus Ls400 most commonly fails on power steering fault and fluid leak. Under 60,000 miles, the main issues are .
How do I check a Lexus Ls400's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.