What goes wrong, what it costs, and what to check before you buy a used Lexus Ls400.
The Lexus Ls400 occupies a niche position on the UK market.
We track 5 known issues across the Lexus Ls400 range, including 2 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Lexus Ls400? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
UCF10 (1990–1994) — Engine options included the 4.0L V8. Our database flags 5 known issues on this generation, 2 of which are rated as safety-critical. The most significant concern is Vehicle structure corrosion reducing assembly rigidity (£1,500–£4,000 to address).
UCF20 (1995–2000) — Engine options included the 4.0L V8. Our database flags 5 known issues on this generation, 2 of which are rated as safety-critical. The most significant concern is Vehicle structure corrosion reducing assembly rigidity (£1,500–£4,000 to address).
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. This affects cars from 120,000 miles onwards and represents a safety-critical structural weakness. The issue is progressive and worsens with age, making thorough inspection essential on higher-mileage examples.
Structural corrosion that compromises assembly rigidity is an MOT failure and makes the vehicle unsafe to drive. Repair typically requires extensive welding work by a specialist fabricator. Costs can range from £1,500 for localised repairs to £4,000+ for complete subframe reconstruction, often exceeding the vehicle's value.
Inspect the wheel arches, sills, jacking points and door bottoms carefully. Press gently on sills to check for soft spots. Look underneath for corrosion on structural components. Check the MOT history for corrosion-related advisories or failures.
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. This affects the fundamental structural integrity needed to safely support suspension loads during driving, braking, and cornering. The issue progressively worsens and can lead to suspension component detachment.
Corroded suspension mounting points can fail catastrophically, causing loss of vehicle control, wheel detachment, or suspension collapse. This is an immediate MOT failure and the vehicle should not be driven. Professional structural repair or replacement is mandatory, typically costing £2,000-£6,000 depending on the extent of damage.
Inspect the wheel arches, sills, jacking points and door bottoms carefully. Press gently on sills to check for soft spots. Look underneath for corrosion on structural components. Check the MOT history for corrosion-related advisories or failures.
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. This affects vehicles from 80,000 miles onwards and can result in complete loss of power assistance. The system runs at high pressure and component deterioration is accelerated by age and contaminated fluid.
Complete power steering failure makes the car extremely difficult to steer, especially at low speeds or when parking. A failing pump can also contaminate the entire system with metal debris, requiring replacement of the rack and all fluid lines. Total system replacement costs £1,500-£2,500.
During the test drive, check the steering for excessive play, vibration or pulling to one side. Listen for groaning or whining when turning the wheel at low speed. Power steering fluid level and condition should be checked on hydraulic systems.
The LS400 suffers from accelerated wear of suspension bushes and joints, failing at 7.6 times the fleet average rate. The heavy V8 engine and luxury car weight place additional stress on suspension components, while the rubber bushes deteriorate with age regardless of mileage. This affects ride quality, handling precision, and can cause MOT failures. Multiple bushes typically need replacement together as they age as a system.
Worn suspension bushes compromise handling, increase braking distances, and cause premature tyre wear. Multiple bush failures often occur together, requiring comprehensive suspension rebuilding. An MOT failure is likely once wear reaches the legal limit. Complete suspension refresh typically costs £800-£1,500.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
The V8 engine uses multiple oxygen sensors in the exhaust system that deteriorate with age and contamination from oil consumption or poor fuel quality. Failed sensors cause poor running, increased fuel consumption, and MOT emissions failures.
Failed lambda sensors cause MOT emissions failures, poor fuel economy, and potential damage to expensive catalytic converters if left unrepaired. The car will typically still run but with reduced performance and higher running costs. Sensor replacement is straightforward but catalyst replacement can cost £800-£1,500 per unit.
Check for any engine warning lights on the dashboard. Ask about the car's MOT emissions history — repeated failures suggest underlying issues. A pre-purchase diagnostic scan is especially worthwhile to check for stored emissions fault codes.
For the full breakdown of all 5 tracked issues with repair costs, see the Lexus Ls400 common problems page.
Based on 7k real DVSA MOT tests, the Lexus Ls400 fails more often than average on several items. The biggest outlier is suspension pin, bush or joint worn at 29x the fleet average, followed by power steering fault (25x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full Lexus Ls400 MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 10k miles) typically costs £80–£120 at an independent garage.
The bigger-ticket items to budget for include timing belt and tensioner (£600–£800), spark plugs (£200–£300), automatic transmission fluid (£200–£300).
See the full Lexus Ls400 service schedule for every interval and cost breakdown.
The Lexus Ls400 has some well-documented weak points, including 2 safety-critical issues that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable.
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Lexus Ls400, we cross-reference the exact variant, engine and age against our database of 5 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 5 known Lexus Ls400 issues. We are not affiliated with any source listed.