LexusJan

Hello! I’ve been lured here by the knowledge and advice of this board and have loved reading everything I’ve found. I bought a dark grey JDM (RHD) 2007 GS460 about 6 weeks ago. A huge upgrade from my tiny 1.5l Mazda! I’m very much enjoying the upgrade, too; as someone who commutes long distance I am grateful to have a slick, tidy and comfortable car to spend several hours a day in. I was extremely fortunate to pick it up below GS350 price.. (confirmed urgent shift overseas), of course that came with knowing it would have problems and quirks to work through. And quirks and problems there are.

I am a novice when it comes to working on cars, but I am lucky to be working alongside my partner who is more advanced and is keeping me calm while we work through the to-do list. We are hoping to do as much work as possible ourselves, only outsourcing when necessary. Trying to get a service manual at the moment (any tips on gs460 specific? Few places are for lot of models and some are very slow to communicate..), but I’d like to get things moving as soon as I can. I’m starting this thread to ask for advice but also with the intention of keeping the thread going as a blog while we work on the car. It will be nice to come back with updates and solutions. We found so much good information here it seems fair to keep it up and share what we learn.

The car was not worked on by terribly good mechanics in past, when they just advise to stick a new battery in instead of fixing the charging system and don't tighten the ABS lines down enough when (assumedly) replacing the ABS Module... yes the ABS lines were tightened and fixed during our test drives, now we will have to re-paint the area underneath it due to to a lot of leaked fluid.
Soon we’ll be working on fixing the touch screen, the seat-heating switch on the driver’s side, checking/replacing transmission fluid and fixing the boot lever rubber (part is elusive so far on boot diagrams). Just ending winter here so it will be great to get out and spend the days working on things. But the more important problems come first…

Often the car can be quite lazy in first gear when its a warm day, but this seems separate to the following issues:

-Sometimes the car is sluggish in all gears and hesitant to change gear. When I try to rev, it accelerates very slowly and without punch; no/slow gear changing, sometimes lurches a bit when changing gears and twice has given a shudder when trying to change gears. Often there is a sulfuric smell that comes with it. Partner says it smells like catalytic converters when a car runs rich (and could be retarded timing/limp mode related). Fuel economy drops sharply during these episodes. I started this week sitting around 11.2kpl/26mpg and after a few days of trouble am down to 8.9kpl/20-21mpg or less.

A good blat often seems to solve the problem for a bit (a week or two) before it comes back, changing gears manually also seems to bypass the problem but this needs more testing before I’m sure.

So far we’ve theorised that it could be a few things: the TCU needing repair or replacement, (especially the alternator diodes/alternator itself needing work), and the tensioner pulley bearing or other belt related bearing assembly having problems. Occasionally the 'whistling noise', usually bearing related, can be heard and once it was particularly loud. Heard this can cause knock sensor to trigger and pull power as one culprit. We’ve already decided to inspect and work on the tensioner pulley if needed – re-packing the grease etc – and will be our first action. Followed by further alternator diagnostics (battery voltages off, idle and 3k rpm are just within bounds but definitely warrant attention - have charged it out of caution a few times but seems to hold voltage if given a blat) and then finally TCU repair at SIA. Any ideas or suggestions we would gladly take on board.

Of course also a code reader will be invaluable before setting out. Have seen a few options, with many different levels of functionality. Of course the most functionality for the dollar is always best. But really this comes down to most compatibility with the GS460.. Bluedriver and Faslink M2 are of interest (easier on a phone) but can't see anyone using them on Lexus related forums. Other option is more expensive Lexus dedicated hardware code reader, reason is to read all the main modules (TCU etc especially) and live data, not just read codes and clear some for ecu and maybe abs if lucky. It costs a lot to send TCU to SIA if it's nothing to do with it (international shipping plus downtime).
For now though might just go with a cheap code reader recommended on clublexus (ELM 327 + torque or techstream). Can these do TCU check? This is a function that is far less common to find that is known working on forum resources. A laptop only based solution is also fine if it's cheap or more powerful at this point.

Our other query is regarding the wipers. When I took possession of the car, it had no intermittent wipers and of course rain sensing didn't work. All other settings worked fine. Every now and then I’ve caught it either not going off when I mist the windscreen, or during the low-full setting it will just stop dead. Resolves itself immediately for the continuous action modes… but still no intermittent wipers.

As per another thread we saw here, we assume it’s the relay and want to change it. But the thread was not for a GS460 and we cannot find where the relay is after checking main fuse boxes in the engine compartment and front passenger compartments. Any 460 owners know its location?


Thank you so much for your help!