What are the most common Lexus LS400 problems?
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 1991 Lexus LS400 has 6 documented issues. The most frequently reported are: Timing belt / water pump service — interference risk on 1998-2000 VVT-i, Front lower ball joint wear and (rarely) separation, Engine ECU/ECM electrolytic capacitor leakage (age-related). Of these, 2 are rated critical and should be addressed promptly.
Is the Lexus LS400 reliable?
The 1991 Lexus LS400 has 6 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 2 issues are rated critical: Timing belt / water pump service — interference risk on 1998-2000 VVT-i and Front lower ball joint wear and (rarely) separation. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Lexus LS400 problems?
Repair costs for known Lexus LS400 issues range from $90 to $1,600, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Timing belt / water pump service — interference risk on 1998-2000 VVT-i, typically costs $800-$1,600 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 1990-2000 Lexus LS400 Timing belt / water pump service — interference risk on 1998-2000 VVT-i?
The 1UZ-FE uses a rubber timing belt with a factory replacement interval of 90,000 miles or 7 years. A widely cited distinction: the 1990-1997 non-VVT-i engines are generally regarded as non-interference (a broken belt strands the car but typically does not smash valves), while t… Repairs typically run $800-$1,600. Severity: high.
What is the 1990-2000 Lexus LS400 Front lower ball joint wear and (rarely) separation?
The front lower ball joints wear out with age and mileage and, in documented cases, have separated/sheared while driving — a serious safety concern at speed. Toyota's own maintenance schedule calls for ball-joint and suspension inspection at short intervals (about every 15,000 mi… Repairs typically run $200-$700. Severity: high.
What is the 1990-1997 Lexus LS400 Engine ECU/ECM electrolytic capacitor leakage (age-related)?
The surface-mount electrolytic capacitors on the engine ECU (ECM) circuit board dry out, swell, and leak electrolyte over decades. The leaking acid corrodes the board traces and solder joints. This is one of the most widely documented age-related failures on the 1UZ-FE LS400 (and… Repairs typically run $90-$300. Severity: medium.
What is the 1990-2000 Lexus LS400 Starter motor failure buried under the intake manifold?
The 1UZ-FE V8 mounts the starter in the engine valley, underneath the intake manifold, rather than at the side of the block. The starter solenoid contacts and motor wear out, typically between roughly 100,000 and 200,000 miles. The failure itself is ordinary, but the location mak… Repairs typically run $500-$1,200. Severity: medium.
What is the 1990-2000 Lexus LS400 Variable-assist power-steering pump/hose leaks (can kill the alternator)?
The LS400 uses a variable-assist power-steering system (running ATF) whose pump seals and high-pressure hoses harden and leak with age. Because the power-steering pump sits directly above the alternator on the 1UZ-FE (worst on 1991-1997 cars), a leak drips fluid straight onto the… Repairs typically run $300-$1,100. Severity: medium.
What is the 1990-2000 Lexus LS400 Oil leaks from cam/crank seals, valve-cover gaskets, and timing cover?
As the car ages, the elastomer seals and gaskets harden and weep oil. The most common sources are the valve-cover gaskets (oil drips onto the exhaust manifolds and produces a burning-oil smell), the front crankshaft and camshaft oil seals behind the timing cover, and the oil-pan… Repairs typically run $200-$900. Severity: low.
