Hey guys, my nephew wants to buy a 2015 IS250, is the carbon buildup thing still a problem with the year 2014 and up and are there any other problems or concerns we have to pay attention to or cope with?
Thanks

 

You may want to ask in the 3IS forum. Although, it's less likely to happen on 2011+ IS250's since they had the revised head (pistons/bore), I won't say it won't happen though since the 4gr-fse doesn't have a self-cleaning mode built into it or both direct and port injectors like the IS350 has. Definitely not an issue like it was on the 06-10 IS250s.

 

2015 MY is250s are still only direct injection so the carbon buildup will eventually occur albeit not as much as the older 2IS, but without port injection the valves will be still be susceptible.

source:
pressroom.lexus.com/releases/2015+lexus+is+250+350+product+specs.download