Mr4btTahoe

Hey guys...

So I've been doing some digging and found that the '06 model year of the gs300 has been known to have issues with carbon build up on the intake valves which will eventually cause misfires, etc. (caused by the direct injection only system and low tension oil control rings).

I believe my wife's car is having issues with this... random little stumbles, random cold start stumbles, lack of throttle response, etc.. very similar to the complaints of the IS250 guys. Her car has ~134k on the odometer and uses between 1/2-1qt of oil between 5k oil changes depending on how it is driven.. so I doubt it is ring related.

So I started trying to figure out a way to fix it without tearing the engine down... and I started seeing a bunch of information on VW and BMW forums about walnut blasting. Apparently it is now a BMW warranty repair on the N54 engine and others (they even sell a special tool). The job involves pulling the intake manifold (I was planning on changing plugs soon anyways so the upper needs to come off.. lower is cake to take off at that point). Starting with cylinder 1, tape off all other intake ports. Insure that the intake valve on #1 is fully closed. Using a shop vac and a portable media blaster (most use harbor freight cheepies).. along with #24 walnut shell blasting material (will remove carbon but too soft to damage metal surfaces).. blast out the port and valve face/stem area and vacuum it out. Continue on with each port until complete.

The process can be seen here on a BMW...
http://www.bmwblog.com/2014/04/24/cl...intake-valves/

On an IS250....
http://carspecmn.com/lexus-is250-and...lnut-blasting/

I've found a few threads on here about guys doing it to the IS250 with good luck... has anyone done it to a GS300? From the looks of things, it all should be the same.

Anyways... I've got the media blaster already... will just need to pick up walnut media, new plugs, intake gaskets, etc.. and knock it out.

I'll probably turn this thread into a DIY once I get going on it.. but figured I'd see if anyone else had any input on it. I figure if it works, I'll just do it every time the car is due for plugs (60-70k or until issues arise). I'm also thinking catch can inline with the PCV system to help prolong the effects.

ibidu1

iTrader: (1)

i would also pour marvel mystery oil (let it soak overnight) into each spark plug hole to remove the carbon on the rings aswell, before media blasting the intake ports

Mr4btTahoe

I may do that afterwords.. just in case any walnut media ends up in the bores.. it'll be easy enough to blow out with compressed air. Otherwise, the bores will be oily and likely for things to stick in the oil. Really, it shouldn't be possible for anything to make it into the cylinders... but we'll see.

Just for giggles, I sent Lexus customer care an e-mail about the issue just to see what they say... may get lucky.