Lexus GS 450h 2008 concerns

[ThE_0nE]

Hello all,

So I bought my GS450h 2008 with 56k miles 1 month ago. Although it feels smooth and everything is working fine I still have a few concerns.

1. When I bought it I drove 400 km (250 miles) at 140 km/h (87 mph) and the average consumption was 9.5 l/100km (22 mpg). This consumption wasn't very alarmist, I was expecting this. But during city drive I see very big consumption. I think if I would drive very slowly (like a grandpa), the best I could get it is something around 15 l/100km (35 mpg). But I if have ocasional quick launch, consumption launches average to 20 l/100km. The consumption data I'm showing here is obtained from car computer. Could not be accurate at all. This is not my biggest concern, but I feel that ICE is being overused due to bad hybrid Battery.

2. Each time I start my car (first time of the day) ICE kicks in. I do feel it can be normal since it is cold in my garage (8ºC). And maybe it is warming up the engine as part of normal procedure.

3. When I stay in the car for long periods of time with READY ON or READY OFF, only using radio, it discharges traction Battery 1 bar in 10/15 min (rough estimate). With READY ON when it reaches 2 bars left (purple) ICE kicks in to charge until 3 bars. One time, I was with READY OFF, heat ventilator ON, radio ON, probably headlights ON and playing with Techstream software checking errors, checking live data, etc... Radio stopped working, and every light in the car started to change intensity from LOW to HIGH (blinking). I know it had 2 or less Battery bars. When I tried to start the car I got warning light say to check something. I think it was related to steering power. And READY ON was not showing. After disconnecting 12V Battery and connecting everything started to work again. I checked 12V Battery health and it was like new. Any thoughts on this? Is it possible that it has nothing to do with the Battery state but rather a parasitic Battery drain? Because Battery feels to hold up from night to day.

4. I'm bought Techstream (bought from Amazon) and it came with V13 and V15 software. Both of them work fine to check codes, live data and customize settings. But when checking live data for Hybrid Control I get error. A fatal error kept popping up and not allowing to go forward. Does anyone experienced this? For insurance I bought another cable from different seller. And I also bought Veepeak OBDCheck BLE to try using Dr. Prius / Dr. Hybrid.

5. When I was driving back home after purchase on highway I turned on Adaptive Cruise Control and several times it stopped working telling me to clean the sensor. I did stop several times and cleaned it. But occasionally error would appear and disappear by it self. Does it happen to anyone else? Car was dirty as it was sitting in garage pretty much all the time. Last year owner drove something like 1500 miles.

6. So I bought this car, the only maintenance information paper I have is regarding oil. It was changed by Lexus 1 year ago, 1500 miles ago. I checked all levels (oil, coolant and brake) all looks good. Oil color looks like new (my friend mechanic said the same thing). I'm sure that car was always services by Lexus as I called to the dealer and confirmed that. I also confirmed that on the Lexus website where I can see miles intervals and dates when the car was assisted but the only thing I can see if the services was minor or major. I went to my local Lexus dealer trying to obtain more history but they couldn't release that information. All I know that the car never changed traction Battery and tires were changed last year.

Having almost no information about the past. What maintenance would you recommend. Should I change oil and filters even though it wasn't driven much? Should I change brake fluid? Coolant? Filters? Spark plugs?

7. Service manual never refers about fuel filter change. Does it even exist? Does it require change?

8. Dashboard rattling noise. I already saw some possible fixes, but does anyone related to this?

 

This will be it for now. I appreciate any help or suggestions.

Cheers!

[ColinBarber]

1. Economy will be worse in cold weather, due to the hybrid Battery not having as much usable capacity when cold and the ICE having to run more to keep the coolant temperature high which is used for the cabin heater.

2. This is normal, especially if the cabin temperature is set higher than the actual air temperature - the system will make the ICE run to provide heat for the cabin.

3. 12v 'aux' Battery is small because it isn't used to start the engine - it is therefore easy to discharge it. Always put the vehicle in Ready mode so the hybrid system is powering the vehicle and charging the aux Battery.

6. Engine oil should be changed every 10k miles/12 months. Brake fluid every 20k miles/2 years. Plugs every 60k miles. Not sure about air filter on your model, probably every 40k miles/4 years but certainly check it every 20k miles/2 years. Coolant at 100k miles, and then every 50k miles.

7. Fuel filter at attached to the pump in the tank. It doesn't need to be routinely changed.

[ThE_0nE]

Thank you so much for the answer @ColinBarber. In question nº3, I'm referring to traction (hybrid) battery and not 12v Battery. The 12v Battery is not that small, it's a 450A with 60Ah. On my old car I had the same Battery capacity and I could easily stay 5h listening to radio while repairing my car.

Do you know exactly what accessories use traction Battery while parked with READY OFF? Like is the radio powers by traction Battery? Seat heaters? etc... Because something is draining very quickly traction Battery and it doesn't feel normal to me.

[Steven Lockey]

1> 22 mpg is shockingly low.
Even in this weather I get 30 mpg+ from mine and its got 170k on the clock and is a year older.
Only time I saw even near 22 was when the traction Battery was screwed.

2> Yeah, completely normal. I think it will always start up the engine just to check it still works 
before you actually start moving. Even in summer I think it was still starting every time if it hadn't
been driven in x hours but would turn itself off after a few seconds until I put my foot down outside
of my car-park.

3> In standby mode, everything uses the traction Battery as far as I can tell. There is a guide
in the manual which you can find online but basically yeah, there does seem to be quite a lot
of draw. I noticed this in mine but I think its just because standby mode has a lot more active
than in a lot of cars. It'll quite happily run the AC with the engine off for example.

5> Thats odd, the adaptive sensor shouldn't need cleaning as it's radar based which is really 
only affected by metal. If its cold enough to form ice on the sensor that could cause an issue
but normal dirt shouldn't affect it too much. Normally its a parking sensors which use sonar 
that need cleaning.


 

[ColinBarber]

9 hours ago, ThE_0nE said:

Do you know exactly what accessories use traction battery while parked with READY OFF? Like is the radio powers by traction battery? Seat heaters? etc... Because something is draining very quickly traction battery and it doesn't feel normal to me.

Nothing uses the traction Battery when not in Ready mode, and everything uses it when in Ready mode. Dropping 1 bar on the display after 10 to 15 mins seems normal to me even if just using the radio as all the vehicle electronics are powered up too - if you have the AC on then the compressor is also being powered by the traction Battery.

[ThE_0nE]

8 hours ago, Steven Lockey said:

1> 22 mpg is shockingly low.
Even in this weather I get 30 mpg+ from mine and its got 170k on the clock and is a year older.
Only time I saw even near 22 was when the traction battery was screwed.

What do you mean by "traction Battery was screwed"? What were the symptoms? Did check hybrid system light got on?

[Mossypossy]

Low mpg at big motorway speed will have nothing to do with traction Battery I would have thought, as it will barely be used.

I got 28mpg with a roof box on a 500 mile motorway journey at those speeds.

[ThE_0nE]

1 hour ago, Mossypossy said:

Low mpg at big motorway speed will have nothing to do with traction battery I would have thought, as it will barely be used.

I got 28mpg with a roof box on a 500 mile motorway journey at those speeds.

I wonder if my low mpg can be explained by old spark plugs (I don't think they were ever changed, but I'm not sure)

[royoftherovers]

20 minutes ago, ThE_0nE said:

I wonder if my low mpg can be explained by old spark plugs (I don't think they were ever changed, but I'm not sure)

You won`t know until you replace them Denis.

[ThE_0nE]

2 hours ago, royoftherovers said:

You won`t know until you replace them Denis.

By any chance do you have the part number for the OEM spark plugs? I have seen some spark plugs at auto-doc 15/20€ a piece (iridium 3 poles).

[royoftherovers]

15 minutes ago, ThE_0nE said:

By any chance do you have the part number for the OEM spark plugs? I have seen some spark plugs at auto-doc 15/20€ a piece (iridium 3 poles).

I don`t Denis--sorry.

Maybe in your Handbook or ask Lexus Dealer or try Google.

[ThE_0nE]

Confirmed with Lexus dealership that spark plugs were never changed. They should actually change them right now. Got a 750€ quote for the job. Includes: oil change, oil filter change, air filter (replaced 2 years ago) change, ac filter (replaced 2 years ago) change, break oil (replaced 2 years ago) change, coolant replacement (replaced 2 years ago), spark plugs change and apparently replace 2-3 of some kind of sealant rings in differential. It is 180.000 km service (110.000 miles) although my car has only 91.000 km and 13 years.

[ColinBarber]

I think the plugs are Denso FK20HBR11. Even if worn they won't make much difference to the economy unless you were also feeling hesitation during acceleration. Whilst the plugs are changed at 60k miles, they are probably good for at least 100k miles.

Worth checking the brake callipers (rear) aren't binding/seized.

[ThE_0nE]

3 minutes ago, ColinBarber said:

I think the plugs are Denso FK20HBR11. Even if worn they won't make much difference to the economy unless you were also feeling hesitation during acceleration. Whilst the plugs are changed at 60k miles, they are probably good for at least 100k miles.

Worth checking the brake callipers (rear) aren't binding/seized.

I do feel the hesitation, but since I just bought the car I'm not sure if that is normal or not. For sure when I quickly floor there is a small delay.

Regarding callipers/disks/pads I checked them this Saturday and they were fine.

[Steven Lockey]

13 hours ago, ThE_0nE said:

What do you mean by "traction battery was screwed"? What were the symptoms? Did check hybrid system light got on?

Yes, had errors on the Battery and codes appearing. Only time I've seen the mpg on mine go below 30 and I check it quite often.
This is over the whole tank however so you might have bad patches below 30.

 

11 hours ago, ThE_0nE said:

I wonder if my low mpg can be explained by old spark plugs (I don't think they were ever changed, but I'm not sure)

I can't imagine the car not throwing errors if multiple misfires are detected..... Check engine light would surely be on if this problem was bad enough to cause this.

 

 

5 hours ago, ThE_0nE said:

I do feel the hesitation, but since I just bought the car I'm not sure if that is normal or not. For sure when I quickly floor there is a small delay.

Regarding callipers/disks/pads I checked them this Saturday and they were fine.

Do you feel the hesitation in sports mode? I drive mine exclusively in sports mode cos it feathers the acceleration to make it feel smooth in normal mode so much it feels like it is hesitating. Turning sports mode on and that goes completely.

 

[ThE_0nE]

2 minutes ago, Steven Lockey said:

I can't imagine the car not throwing errors if multiple misfires are detected..... Check engine light would surely be on if this problem was bad enough to cause this.

I did checked for misfires in Techstream, the count was 0. And no error codes anywhere.

3 minutes ago, Steven Lockey said:

Do you feel the hesitation in sports mode? I drive mine exclusively in sports mode cos it feathers the acceleration to make it feel smooth in normal mode so much it feels like it is hesitating. Turning sports mode on and that goes completely.

For sure there is less hesitation in sport mode, but I would say I still feel some. Not instant acceleration. In normal mode, it has a noticeable hesitation and it feathers. It's very hard for me to tell this, I'm used to drive a considerably slower car with 101HP 1.6 gas

[Steven Lockey]

Ha, my only two other cars were a Rover 25 1.4l (78hp?) and a Citreon Saxo 1l (50hp)
Its such a big difference, particularly when at speed. First time I drove it, nearly went into 
the back of a truck on the dual carriage-way when I put my foot down to overtake quickly
and didn't realise quite how quickly it accelerated compared to my past cars! 😉

When I'm in sports mode, its incredibly responsive the the gas pedal. Might be due to the fact
I also keep the hybrid in power-assist mode which means the electric gives it a boost off from
low speed.

Automatics also naturally are slightly more laggy on acceleration than manuals so that might be
what you are noticing. One of the reasons I really like the 450h is cos the traction engine seems
to compensate for that completely in power assist mode.

[ThE_0nE]

8 hours ago, Steven Lockey said:

Ha, my only two other cars were a Rover 25 1.4l (78hp?) and a Citreon Saxo 1l (50hp)
Its such a big difference, particularly when at speed. First time I drove it, nearly went into 
the back of a truck on the dual carriage-way when I put my foot down to overtake quickly
and didn't realise quite how quickly it accelerated compared to my past cars! 😉

When I'm in sports mode, its incredibly responsive the the gas pedal. Might be due to the fact
I also keep the hybrid in power-assist mode which means the electric gives it a boost off from
low speed.

Automatics also naturally are slightly more laggy on acceleration than manuals so that might be
what you are noticing. One of the reasons I really like the 450h is cos the traction engine seems
to compensate for that completely in power assist mode.

When you say you use sport mode. Is it sport button or hybrid-power button? Because I thought sport button is only for suspension.

Although I didn't accidentally drove against anything, I did press the brake once as I would press clutch. That was a quick stop.

[Britprius]

On 1/19/2021 at 9:53 AM, ThE_0nE said:

Because I thought sport button is only for suspension.

The sport button alters the suspension, the throttle response, and the steering ratio. The number of turns from lock to lock is reduced.

John. 

[ThE_0nE]

4 hours ago, Britprius said:

The sport button alters the suspension, the throttle response, and the steering ratio. The number of turns from lock to lock is reduced.

 

Then what's for the Hybrid Power button?

[Steven Lockey]

On 1/20/2021 at 6:41 PM, ThE_0nE said:

Then what's for the Hybrid Power button?

That changes the way the traction engine is used, so it will use it more when you put your foot down
and less for cruising. 

I keep it in power assist mode, seems to make little difference to fuel economy and makes the accelerator a bit
more responsive.

[Spacewagon52]

These cars are quite amazing!

[Lwerewolf]

The AC drops the Battery in no time flat.

Some other things that are running off the traction Battery when in "READY" mode (well, off the 12v... which is fed by the traction Battery 😛 ) :

-Auxiliary transmission oil pump
-Inverter electric coolant pump
...plus lights, radio, sensors, etc, etc...

Fuel consumption:
Highway sounds fine, if you had a 4th gen it would've been lower (atkinson-cycle engine and no, it's not slower).
City is ridiculously high - 14/100 is what I've heard of people getting in gridlock traffic jams... well, not gridlock, but Moscow rush hour is pretty bad 😛

What do the buttons do - "sport" blocks the low-speed orifice in the dampers + some other things. Power - changes throttle map, but so does sport. I need to look up the "new car features" of the service book again. Meh.

"Hesitation" - if you put the transmission in S-mode (leave it in 5th or 6th or whatever, it doesn't matter), the engine will not turn off - you still have to turn it on somehow (blip of throttle, heater to max, anything). The inverter can draw ~35kw of power from the Battery. The engine produces up to 217kw (above 140kph where it can stay at max RPM). Don't expect much electric assist, other than at extremely pedestrian speeds - more than ~15% throttle generally means the engine needs to fire up (if not running) and rev first.

Get hybridassistant and a compatible adapter. I wouldn't cheap out, even though the good ones are generally more expensive than the good techstream-compatible adapters... other than the mongoose pro, of course, but that's OEM 🙂

See this:

...and think twice before flooring it, or at least log and review those temperatures. LHD inverters are in short supply.

Re: Battery - I'd start looking at serious rebuild/replacement options. Do it once, do it proper. You'll understand once you read up a bit on how these things actually "fail".

[ThE_0nE]

On 1/18/2021 at 6:07 PM, ColinBarber said:

I think the plugs are Denso FK20HBR11. Even if worn they won't make much difference to the economy unless you were also feeling hesitation during acceleration. Whilst the plugs are changed at 60k miles, they are probably good for at least 100k miles.

Worth checking the brake callipers (rear) aren't binding/seized.

Now I totally feel no hesitation after changing the spark plugs in normal mode (haven't tried sport yet)! The the fuel economy feels much better, but I only drove 5kms. So not the best indicator. But before changing even driving 5kms the fuel economy would easily go over 18l/100km, now it stopped at 12l/100km. But I feel that it will get even better.

Regarding experience of changing spark plugs:

- The left side of the engine piece of cake. But the right side took little more time, mainly I had to try to take the wire harness out of the way as possible. Also had to take out of the way ABS/VSC controller box and brake fluid.

Old spark plugs:

Guide (same way to remove on the left side of the engine, on the right side little different but not very difficult):