703

Anyone notice when you lift the gas off after acceleration at around low city speeds and the engine shuts off, there is a soft thump noise that comes from the rear? Maybe around the differential area.

this may coincide with switching to regen.

or is it just an issue with mine?

chasep

I can usually hear when the combustion engine turns off, but I don't hear any thumps from the rear on deceleration.

703

what sound from the rear do you hear when the ice turns off?

chasep

I don't think I hear anything from the rear when it turns off. The hum of the engine goes away and there is a slight momentum shift as the internals come to a stop. That's about it.

Im2bz2p345

I would get this looked into by a Lexus dealership. I have no sounds at all from the rear of my vehicle when it switches between the ICE and battery-only power.

~ Im2bz2p345

703

Thanks. I will also check the ecvt fluid level.

Hues10

I don't think you can really check the ECVT fluid level, without actually taking out the fluid. No dipstick, sealed, lifetime, etc. Has been discussed to no end on the regular GS 350 forum. We haven't really discussed the transmission fluid change on the Hybrid forum. It gets nasty it seems as people are very opinionated on the topic. But good luck. To second IM2bz comment, no sound from rear when ICE shuts down. I only really notice the engine starting or stopping when it is first warming up in the morning. Unless I step on the gas a little. Like I did this weekend when I stepped on it, got it to over 90 like nothing, and had to back off. My fiance said she knew I did something, but did not know what I got up to. It was that quick and smooth. Wish I drove highways more.

703

The way to check it is to open the fill plug and pump the Toyota WS fluid in. The car has to be level to +/- 1 degrees.

I can use a syringe to do this so I can measure how much goes in before the fluid comes back out.

yes definitely something funky is going on with mine when the ICE cuts off.

GoGadjetGo

I have the same thing. Almost sounds like there is too much play in the driveline. It makes a soft clonking noise as ICE power comes off.

Did you manage to find out what was causing it in your car?

bclexus

Agree! I don't have any sounds from the rear either.

I only have a cool little silent twisting torque movement when the EV motor activates/deactivates while sitting for a red light to change...

GoGadjetGo

@Leadlap did you resolve yours. What was it?

gripau1

You didn't mention the age and mileage and service history?
I would put the car on a hoist or jack stands and first check if the driveline coupler has too much slack or the rubber has deteriorated and also check the differential and transmission mounts.

GoGadjetGo

2012. Service history is not known. I’ve had it 6 mths. It has travelled 110,000 kms.

I have booked it in with Lexus to take a look on Friday 5 July. Will let you all know what they find.

gripau1

Last year when I was looking and test driving another GS450h 2015, this one had about 60k km. You can tell it was neglected even with Lexus stamps in the book. The diff or wheel bearings had a grumbling whine when coasting above 60km/h and it wasn't the mismatched tyres.The transmission when transiting from petrol to EV and back to petrol had a noticeable backlash. I went around the block and returned the keys straight away. No thanks and kept looking.