Buyers GuideAll cars have faults even the venerable LS400 shows up a few features that the manufacturer didn't quite plan on.
I have listed some faults specific to the Lexus LS400 below that are worth keeping an eye out for.
This list is in addition to my LS400 Buyers Guide
For more help you can't go past the various forums online and my favorite site LexLS.com
Lacquer coating on alloy wheels peels off allowing them to oxidise, it can some times be quite bad. You can get them refurbished for about £65 a corner if they are not too far gone.
A full Lexus or specialist service history is always worth looking for. Some of these cars have covered a high mileage and if servicing has not been done on schedule it can cause major problems.
It is best to see records of the auto transmission fluid and filter having been changed every year, that is not critical but it is essential that the timing belt has been changed at 60,000-mile intervals.
The catalytic converters are expensive on the Lexus LS400 £700+ each so check them carefully but the exhaust rarely needs replacing,
It's unusual for a LS400 to have done less than 100,000 miles these days as even the youngest car is 16 years old, suspension wear is probable or even inevitable over 100k and control arms and ball joints will likely need replacement, check the cost to do it.
The steering wheel adjust motors can become faulty and are tricky to fix and the power steering commonly leaks on the earlier cars.
The bonnet struts all lose their gas over time, replacement are £50-70 for a pair and are an easy fit.
The leather seats can wear badly on the Lexus LS400, particularly on the early cars and different colors seem to fair better, Gray has always been my favorite and it wears reasonably well, Black is also durable but . Look for, wear on the bolsters and any tears. The heated seats are also known to fail and are not really fixable.
The LCD display on the climate controlled heating/cooling is a well known fault, genuine parts are expensive. An aftermarket repair is available but it it is still over £200. Many owners just put up with this, the rear vision mirror is also known to suffer with a similar fault.
The traction control can throw up a warning light, I have never had this but it is reported as a common fault on the Lexus owners club site. Apparently the most likely culprit is the speed sensor and that costs £300+
This is a heavy car and one that's done over 100,000 is very likely to need some suspension work. usually ball joints and control arms. The parts are not too pricey if you don't use original parts but the labor is always a bit of a hit.
Air suspension was a premium option on the LS400 when the car was new but as a result is very costly to repair if you have a fault total in the cost of new shocks for each corner. A retro fit to standard shocks is apparently possible but is unlikely to be financially worth while now.
The Satnav which was included on the last LS400's Mk IV is becoming a problem, it works fine but is now very dated and if you have a CD prior to version 3.7 it is to be blunt rubbish.
The latest software version is apparently v8 this was released in 2008 and it doesn't accept postcodes because there just isn't room on the CD, if you need to upgrade a new CD retails for around £80-100 but is sometimes available on eBay. I take a Tom tom along as well. The later Lexus models use a DVD and obviously that wont work in the CD based LS400 system.
Apart from all of that be under no illusions about a Lexus like any car basically anything can go wrong but it is a quality product and if well maintained it is a good starting point and I still love mine (I still do in 2016).
I visit this US Lexus forum regularly and it is a great resource and there are several others if you do a search.