Lexus GS 300h

CatPower · October 31, 2023

Hello peps. Just acquired recently a GS 2017 plate, and discovered that the rear windshield demister is not working at all. The mirrors work just fine, and the light of the demister switch is on so I don't know where to start looking to sort it. Any ideas ?

Thanks in advance ✌️

ColinBarber · October 31, 2023

That seems an odd fault, normally these are 100% reliable on a saloon car where the heating element cannot easily be damaged. Is the rear screen genuine, or has it possibly been replaced?

Does everything else work ok, including the Air Con, as the demist signal passes through the AC control unit?

There is a relay that operates the rear screen element, but it isn't a standard cheap mechanical relay, it is a solid state one with additional circuitry and around £100, not something I'd recommend replacing without doing proper fault finding to be sure it is the problem.

Was this a private purchase or via a trader? If a trader then take it back and get it fixed as all faults within the first 6 months are assumed by law to be there at purchase unless the dealer can prove otherwise and they must fix the problem or compensate you.

CatPower · November 1, 2023

Thank you for the reply. Tbh the glass looks genuine and no sign of repainted job, and the aircon works just fine.

I bought it from a trader, but he said when I bought it, that the warranty covers major engine or gearbox failures only, so I guess he won't bother...

I will check the fuses first and the connections with the glass, and take it from there.

I'll be back as soon as I have an update

🙏

ColinBarber · November 1, 2023

2 hours ago, CatPower said:

I bought it from a trader, but he said when I bought it, that the warranty covers major engine or gearbox failures only, so I guess he won't bother...

He can say what he wants, but legally he has to, or you can get it repaired elsewhere and he has to refund you (his choice).

https://www.which.co.uk/consumer-rights/advice/the-car-i-bought-has-a-problem-what-are-my-rights-aAnMC5b0ZzJb

CatPower · November 9, 2023

Hi peps. I don't know how but now it seems to be working... All I've done was to wipe the back windscreen with a microfiber cloth and some MrMuscle window cleaner. After that it started to work.

Long story short thank you everyone for your help 🙏

CatPower · November 9, 2023

Oh and another thing, how much engine oil this engine supposed to take, because I've seen some articles saying it takes only 4.5L, and some saying in takes up to 5.7L...

A bit confused 🤔

johnatg · November 9, 2023

Here's an extract from the Workshop manual.

For the usual oil and filter change it takes 4.5 ltr (I find maybe a bit more - up to nearly 5 ltr)

From a dry engine (eg after rebuild) it would take 5.9 ltr.

CatPower · November 11, 2023

Thank you. Already bought a 5L Mannol oil, with all those other specs.

johnatg · November 12, 2023

I've used Mannol 0W-20 but I've switched to 5W30 - it's a compromise between engine protection and fuel consumption.

Have you checked how to drain and remove the oil filter?

In theory you unscrew the cap with a 3/8" driver extension bar, then insert the plastic spout which comes with the filter. However I've always found that the whole filter unscrews when you try and remove the cap. Anyway, if it doesn't you definitely need the special oil filter removal tool which fits most Lexus and many Toyota models. You need it to replace the filter to the correct torque before replacing the cap to a much lower torque. There isn't room around the filter to use any generic filter removal tool.

My drain cap is completely jammed into the filter housing and I risk damaging the plastic filter housing in attempting to unscrew it. I've recently bought a metal (alloy) filter housing to replace the plastic one but I haven't fitted it yet - that will happen at my next oil change - quite a while yet.

The torque for the oil drain plug is 30 ftlb, oil filter housing 18 ftlb and the oil filter cap 9 ftlb.

CatPower · November 22, 2023

Thank you again. Managed to change the oil, with no major incidents 😁.

All good 👍

Notamech · November 25, 2023

On 11/12/2023 at 10:55 AM, johnatg said:

I've used Mannol 0W-20 but I've switched to 5W30 - it's a compromise between engine protection and fuel consumption.

Have you checked how to drain and remove the oil filter?

In theory you unscrew the cap with a 3/8" driver extension bar, then insert the plastic spout which comes with the filter. However I've always found that the whole filter unscrews when you try and remove the cap. Anyway, if it doesn't you definitely need the special oil filter removal tool which fits most Lexus and many Toyota models. You need it to replace the filter to the correct torque before replacing the cap to a much lower torque. There isn't room around the filter to use any generic filter removal tool.

My drain cap is completely jammed into the filter housing and I risk damaging the plastic filter housing in attempting to unscrew it. I've recently bought a metal (alloy) filter housing to replace the plastic one but I haven't fitted it yet - that will happen at my next oil change - quite a while yet.

The torque for the oil drain plug is 30 ftlb, oil filter housing 18 ftlb and the oil filter cap 9 ftlb.

Just my opinion but you may be better off buying a new original plastic replacement filter housing rather than an aftermarket aluminium one. The reason being that these filters have a bypass valve and you done want a china made unit with a cheap generic spring. I mean it will most likely work but the risk of it failing is higher. These things are meant to be precision made

johnatg · November 25, 2023

You might be right.

But I have to say - the by-pass valve is only there in case the filter gets blocked - I always change the oil and filter every 5K miles so it is very unlikely that the filter will get blocked. I don't think there's anything very precision about the valve mechanism. The plate carrying the filter centre tube pushes down smoothly against the spring.

The ally housing looks very well made - smooth casting and sharp lettering where the torque specs are 'embossed'. I think it's an improvement over the plastic original.

I think 'made in China' is nowadays a rather dated dismissive. We used to say that about 'Japanese' Those days are long gone.

CatPower · November 28, 2023

People, I had a thought about the driver seat the other day. Just wondering, does anyone know if the seat plug is the same for the executive editor and the F-sport ?

I was wondering if I could swap the driver seat because mine has less adjustments than the F-sport trim.

Just asking for future, in case I find one for sale and want to swap it.

Thanks 🙏

johnatg · November 28, 2023

I think you would have more to worry about than the plug. The seat controls are managed by the main body ECU and operated via CANBUS. I suspect that the higher spec seats will have different settings in the ECU.

I could be wrong - all the functions may be built in to the ECU with redundant circuitry and software but I don't think that is the usual Lexus way. They generally set up the ECUs for what is in a specific car type.

CatPower · November 28, 2023

Thank you for the prompt answer. I will ask around too. Might have someone who worked at Toyota for a long time. Might know about this thing.

Thanks again 👍

CatPower · January 4

Hello people again, and Happy New year!

Quick question, does the gearbox oil need changing on the GS300H ? Heard all sort of stories and I'm a bit confused now... 🤔

ColinBarber · January 4

6 minutes ago, CatPower said:

Hello people again, and Happy New year!

Quick question, does the gearbox oil need changing on the GS300H ? Heard all sort of stories and I'm a bit confused now... 🤔

HNY 🙂

Officially no, unless you tow and therefore fall under the severe service schedule (in which case if should be changed at 60k miles).

CatPower · January 6

On 1/4/2024 at 1:41 PM, ColinBarber said:

HNY 🙂

Officially no, unless you tow and therefore fall under the severe service schedule (in which case if should be changed at 60k miles).

Thank you for the info 🙏

So basically no matter what milage you're at ( mine just above 110k now ), you don't need to touch the gearbox... Right ?

Only if you do towing, which is not my case !

ColinBarber · January 6

3 hours ago, CatPower said:

So basically no matter what milage you're at ( mine just above 110k now ), you don't need to touch the gearbox... Right ?

Officially yes. Lexus state the transmission fluid is for life and doesn't need changing. Some people prefer to change it every 60k or 100k miles as there is no question the fluid will degrade over time and use - just whether it degrades enough to be an issue and certainly there are many Toyota and Lexus hybrids with 150k+ miles without ever having had the fluid changed.

johnatg · January 6

I think it depends to an extent on how long you plan to keep the car. If you are going to drive it for say 4 more years or past 150K it might be judicious to change the gearbox oil in the near future. Otherwise probably don't bother.

'Lifetime' fluids don't necessarily mean real lifetime when a car gets older - most manufacturers don't really expect their cars to last more than about 15 years or 150K miles and if you're still driving then you're on your own! Having said that I'm sure there are GS cars around with many more miles without the fluid being changed (as Colin just said whilst I was typing this reply 🙂)

IMHO

The GS300h uses the L210 transmission - GS450h cars use the L110 transmission. It looks rather easier to change the fluid in the L210 so it shouldn't cost too much. Probably best to have it done by a Lexus dealer or a really experienced indy.

You can change most of the fluid in one go - the 'bit at a time' as per Lexus auto transmissions doesn't apply to the CVT boxes.