I am writing this thread as a warning/advisory for current and/or future owners. I recently acquired a poorly maintained 2014 RWD GS350 with 308,000 miles. The car was obviously beat on with all the undercarriage damage of it bottoming out and lack of maintenance. The stack of service records and Carfax records indicate it hasn't been to the Lexus or Toyota Dealer in over 200,000 miles. It has been to Walmart and Take 5 for oil changes every 8-12k and an independent shop for tire changes and brake pad changes changes every 40k. It had the serpentine belt replaced at 200k and does not show any cracks 3 years later at 308k. The water pump, wheel bearings, alternator, fuel pumps and struts all appear to be original as were the spark plugs which had some electrode wear but didn't look too bad. The cylinder #5 plug did show signs of a little oil burning but nothing to be alarmed about. Argue with me all you want on if these are original plugs. My Lexus LS600 which uses the same FK20HBR11 Denso's which I know were original at 270k and had similar electrode wear. The valve cover O-Rings are not leaking oil yet neither are the valve cover gaskets. The boots on the front end and suspension components are all still good, no issues with control arms or ball joints however there is excessive wear on the inside of the front tires which I am hoping an alignment may resolve.

As far as the common problems:

1. Sunroof seal - $60 from Bell Lexus, took me 30 minutes to install. I cleaned the drains with a weed wacker string.
2. Melting dashboard - I do not have this problem, the previous owner used a windshield reflector which preserved the interior.
3. AC servo motors - Historical B1454 code was stored which is the "easy servo" to replace which can be replaced without pulling the dash. 30 minute job. I performed an initialization using Techstream and it has not had an issue return so far but it will probably come back.
4. Timing cover leak - There is some grease near the bottom front of the engine but its a minor seep, no drips yet. If it starts dripping its time for 5W-30 right?
5. Radio amplifier failure - No issues here yet, I hit the trunk seal with Gummi Pflege Stift and removed the bumper cover to fix a dent and cleaned the baffles near the electronics and hit them with some Gummi Pflege Stift.

I have replaced most of the fluids on the car so far, coolant, brake fluid, rear diff, and the engine oil. All the fluids looked nasty except the coolant but I didn't check the pH prior to the 2x drain and fill. The transmission fluid is original as far as I know so the solenoids and probably in the process of getting clogged up like a typical Aisin with "Toyota Lifetime Fluid" but on the other hand the clutches are probably on their last legs. My concern is if I do a drain and fill I may lose the friction of the embedded clutch material within the fluid which will cause the 7th and 8th gear to fail which I don't want to risk at this point. If the solenoids start locking up I'll drop the pan and clean them out and then it gets a drain and fill as it probably deserves. I am leaving the transmission fluid alone for now. A used GS350 transmission with 200k less miles is under $1k in my city at the junk yards so I will just go that route if it craps out.

I'd like this car to make a cross country trip. I don't want it breaking down a thousand miles from home. I'm thinking of replacing the alternator and fuel pressure sensor proactively as both seem to be a common (disabling) problem. Are there any other relevantly inexpensive parts which tend to fail on these cars which should be replaced proactively on a high mileage version? I only care about disabling issues that would leave it on the side of the road.

 

Have you considered a rental car for your cross country trip?

 

308,000 Miles!

You totally blew THIS OP's narrative of Lexus not being reliable out of the water - as well as some people's heretic mindset to do maintenance that Lexus recommends not to do!

 

What's this about melting dashboards? I haven't been on the forum much for a year or more, and I haven't heard of it.

I'm not worried about my car. I already have a dash mat and use a windshield screen to keep the sunlight out.

 

I think it's a fairly rare issue on the 4GS. I did come across a 2013 that had it a few months ago. Lexus did put out a TSB for it years back.

 

@NickDangr - The melting (sticky) or cracked dashboard issue was for certain Lexus models built as early as 2003 (4GS models built only in the 2013 - 2018 year range) that used a dash material which was prone to dissolving/deterioration due to intense heat and radiation from the sun.

My 2018 GS 450h is not included in the TSB because the dashboard is a completely different material compared to what was used for my 2013 model year GS 350.

Lexus TSB ► HERE

 

just bought a 2013 gs350 awd with 245,500 miles.. wish me luck!

 

Do you know anything about the car's history (type of use, location of use, etc.) and its maintenance history?

 

If anyone has the problem do you know if the 2018+ is compatible to put in one's 2013 - 2017?

 

I do not know for sure, but I do not think a 2018+ 4GS dash would necessarily fit or be a replacement for a 2013-2017 4GS.

The dash material in my 2018 GS 450h is very different from what the dash was in my 2013 GS 350.