ESh

2007/ES350.

I got this car in december 2014 and yes, there was this well known piston slap noise on cold mornings.
The dealer where the car has been maintained did an oil change at 54 400 miles and they added bulk oil 0W-20. I think that's a pretty thin oil for this engine, also the manual recommends 5-30.

So I bought a box of Amsoil 5-30 Signature Series, the OEM filter and did an oil change.
I could immediately tell the difference, the piston slap started to fade and the MPG went up.
They say that this oil will improve the fuel consumption, and that's true.

But the most important thing is that piston slap noise started to fade immediately and now after 2500 miles there's around 10% of the piston slap noise.
The engine is smooth as silk and I'm really happy with the result.

nevernu

and what is a cold morning in Skorraq

ESh

Around 28.

mlacomb

It's probably not piston slap; been mentioned a few times here. Has to do with the VVT-i; my 2008 has it and Lexus didn't do anything, stated it's normal. I didn't have the TSB in front of them though.