The 1990-2000 Lexus LS400 is widely regarded as a dependable and reliable vehicle that is well designed and built. However, there is no such thing as a perfect, trouble-free vehicle. While it is better than average, the LS 400 has a few common problems that potential buyers should be aware of.
Starter Motor
On most small block V8 engines from Ford or Chevrolet, the starter motor is easily accessed from the bottom of the vehicle. The 1UZFE 4.0L V8 engine in the Lexus LS400 has the starter located in a very inconvenient place – underneath the intake manifold. The starter is prone to failure between 100,000 and 200,000 miles. During the removal of the intake manifold, it is also likely that the heater control valve will crack and will also need to be replaced.
LS400 Starter Motor Location under the Intake Manifold
Engine Mounts
The Lexus LS400 uses special fluid-filled engine mounts that reduce vibrations in the car. Over time, they may collapse and fail, resulting in increased vibration. They are surprisingly expensive to replace on the LS 400 compared to the simple rubber mounts used on other vehicles.
These fluid-filled engine mounts have collapsed, and one of them has completely sheared off.
Timing Belt
The timing belt sets the timing for the entire engine, keeping the camshafts and the crankshaft synchronized. This is not thin like a fan belt – a timing belt is a heavy duty belt with rubber teeth that loops around a number of pulleys and tensioners. The 1UZ 4.0L V8 engine uses a timing belt because Lexus engineers determined that it would be quieter than using a traditional timing chain.
Timing chains generally last for the life of the engine, whereas the timing belt should be replaced every 90,000 miles or 7 years. In addition, there are two timing belt idler bearings that must also be replaced with the belt. While the car is apart, it is strongly recommended to change the water pump too. This is absolutely a dealership level repair and should not be attempted by the home mechanic.
The 1990-1997 1UZ-FE engines are non-interference engines, however the 1998-2000 engines with the VVT-i intake manifold ARE interference engines. A broken timing belt on these engines would be catastrophic.
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- Lexus LS400 Timing Belt
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- This is a serious belt
Power Steering Pump
The LS400 has variable power steering, but with time and age the seals and hoses of the pump may develop leaks. In this case, any leakage is likely to take out the alternator as it is located directly beneath the power steering pump. You can do this yourself, but it is pretty involved. Watch my video below to see how I replaced my own power steering pump.
Tips for Potential LS400 Buyers
If you are in the market for a Lexus LS400, you should ask the seller for records of when the timing belt was last changed. If the engine mounts have collapsed due to age, you may notice some vibration when idling or when shifting from Park into Reverse or Drive. A starter motor that is on its way out may take longer than normal to crank, or may not show any symptoms at all until the day it fails.
These items should not scare you away from buying an LS 400, but they are definitely worth knowing about before you buy!
