carbon build up in gs 300 and 250 DI engines

[oldjoe]

this seems to have been a problem in the states which Lexus acknowledged.  wondering if anyone on here has had the problem and had it rectified by Lexus as it can result in a complete top end rebuild.

[Jamesf1]

I dont think this has been an issue in the UK due to fuel difference. However, using Shell V power one ever few fill ups is not a bad idea for its cleaning properties

[Jamesf1]

actually I think im wrong in my reply, see this thread

 

[oldjoe]

interesting article. i am sure i read somewhere that Toyota added an extra injector to their engines that sprays some fuel into the inlet tract to wash the valves off but cannot remember which engines and when from. reading it again it looks as though the 350 engines have a combined DI and conventional system. if anybody could confirm that it would be good plus if any of the other engines have it. a link to the way it has been dealt with in the states

 

https://www.clublexus.com/forums/is-2nd-gen-2006-2013/655541-is250-carbon-build-up-csp.html

[oldjoe]

RX 350 is conventional. LS350,GS350 and 460 seem to be combined system, there may be others