Hello Everyone, Although i'm on to my forth Lexus I am new to this Forum.
I have had 2 LS400'S and an LS430 but a few weeks ago I decided to move
down to the second division and bought a GS300 SEL (06) with 14000 miles.
Before buying the GS I read all the reviews and most of them said that the
GS300 V6 has a very smooth quiet engine. I have to agree that my Lexus
is quiet with the windows closed but when the drivers side window is open
I can hear a noise similar to a loose tappet. This noise is even louder
when passing a wall as the sound echoes back. Asked my local Lexus Dealer
to check it out and they said it was just engine tick. Maybe this is normal for
a GS and iv'e been spoiled driving an LS for so long.
Anyone else got the same problem.

I have exactly the same problem. Mine is a 2006 GS300 SE-L with 52000 on the clock.
All is quiet when driving and really quiet at tickover but with the windows wound down and a wall nearby or in the garage it sounds like a tappet needs adjusting or something.
Years ago in my Mini or Scimitar days I would whip the rocker cover off and adjust with my feeler gauge, no probs.
Not sure what to do now or even if there is any adjustment.
Does anyone else have the same problem ? Does anyone know whether this is a common problem which can be adjusted at the dealers ?

I have the same problem. As the car is pulling away I could hear the ticking noise coming from the engine. Anyone know how to rectify the problem.

Does anyone know whether there is any kind of valve adjustment on the MK 3 GS300 ?
Mine is still sounding more tappety than it should for 55K miles when at idle.
I thought the tappets were lash adjusters and were oil driven and therefore automatically adjsuted but the Lexus service sheet hints at 'extra charge for adjustment' on the valve section.
Maybe Lexus can adjust something ? Anyone had this done ?
Thanks.

Just an update to this topic for anyone interested.
I have been worrying about the engine tick for quite a while now so I bit the bullet and took the car to Lexus Newcastle with wallet in hand ... and a lump in the throat !

The technician guys there checked out the engine tick.
They even compared the engine tick to one of the bosses low mileage 2009 GS and the engine tick was the same.
I was advised that the engine tick which is audible when parked near a wall or listening with the bonnet open is not valve noise.
The noise is actually injector noise which is more discernable as a tick when the engine is ticking over.

I must admit that I have been researching this issue on other forums in the US and they too say that the noise is in fact injector noise and
valve noise is kept to a mimimum by the oil pressure controlled lash adjusters so no valve adjustement is required.

So the info given by Lexus Newcastle and the comparison made with a newer GS supports this and puts my mind at rest.

It seems that I have been worrying about nothing and I hope this helps other owners rest happy at night knowing that it is not really an issue.
Maybe we are getting too fussy. The GS is silent when driving, just dont park next to a wall with the windows down or you will start fretting like me

I just put a deposit down today on a gs300 se-l, 55 plate and i heard the ticking when i fired up the car, its been niggling away in the back of my mind all day, I'm glad someone discovered the answer, that 's taken a weight ioff my mind. Thanks buddy for the Update.