Thought we were talking about a GS here I'm sorry, yea in that case would be premium fuel, but somehow missed that sorry. But FYI, running sea foam the way I mentioned as well as adding it also to your gas, oil prior to changes, and crank case have all proven there success.. It's not something I'm preaching because it's a bunch of hokis pokis and unicorns.... Try doing a bit of research, possibly reading all million accounts of running it through your vacume line and all other methods and if your knoledgable and experienced with motors, and what products such as seafoam and other detergents contain, then I don't see any reason why you'd say such a thing, and I'm confident you would probably then agree. I'm not in anyway suggesting this is even close to the answer to his issues lol, but like someone mentioned, get a colonoscopy for preventative measures right?same applies here.... Kinda... Lol.. Rather than giving you the answer, I'd rather have you read from other people so I don't seem biased. And by the way, there's no sure telling if this car is pinging or not unless I drove it and heard it myself... I simply gave suggestions that may help HIM determine what the dealership.... Indeed said it's doing is true.. right? But I wouldn't leave other possibilities out, could detonation, timing, hell even a clogged fuel filter, you never know... for all we know... I don't know... But I can def. Help guide him in the right direction to possibly figuring it out from experience, before he destroys that motor.. But for educational reasons, I want you to try this:
Typed in seafoam in google and randomly chose one, skim through it and I will too... could be negative things for all I know.

http://forums.nicoclub.com/how-to-seafoam-your-engine-the-right-way-complete-diy-t126583.html

It's a forum... So may not hold much merit, but let's find out what people say on it.

Btw, you'd do the seafoam through vaccum prior to changing plugs... It's a difference you very much significantly feel it's actually hilarious... Anyhow, enough seafoam talk the stuffs to petty... Ha...

 

Bob-

I was actually being facetious in response to using premium gas on the ES. I think GSGenesis was referring to his GS, not the ES which is this the discussion for this thread. And Sea foam for a car?? Never heard of that, nor would I even try. Techron is the standard for carbon buildup in the intake or fuel system cleaner.

Sorry I wasn't clear.

 

After reading Lesz last post I'm inclined to agree with him in that the question is why aren't the skilled service personnel seeing (and hearing) this issue? Also, why it's inconsistent. Could be that its not "pinging" or pre- detonation at all.

 

Good possibility.

 

Possibly, but unlikely on a new Lexus. I'm sure the OBDII would catch and record that.