johnxyz

Was reading about the carbon buildup issues with gasoline direct-injection engine cars and Audi was the worst of the bunch - drivability problems and costly head/valve/throttle body cleaning issues.

But the Lexus IS line was also cited as having carbon build-up problems. I'm not sure if the other Lexus engines have GDI or not but those that did (or other Toyota engines) some had an engineered port by design that blew out/burned off the fuel before carbon build-up.

I'm looking at used IS's (and SC's) and if you can comment on any issues with your IS due to carbon problems from the DI, would appreciate it.

BTW the V8 isn't DI, right? Thanks

Defender46

iTrader: (2)

There are direct injection and also engines with dual-meaning port injectors AND direct injectors, the 250's have direct only and a little more carbon buildup, the 350, and the v8s in the ISF and LS460 have direct and port injectors. Dealers in my area do an intake system cleaning that really helps with the carbon build up every 30k, with regular maintenance there isnt much of a problem. So if you buy a used one, try to get this intake cleaning done, and pay attention for a rough idle at start up or after driving the car kinda hard-those are signs of the carbon. End of the day, it's not a MAJOR problem and is kept away with regular service similar to injection flushes.

johnxyz

Thanks - exact answer I was looking for. Just did a search and several specific threads came back on 250 carbon build-up. Oh well - I'll go for for the used IS or GS 3.5 or a used SC430 and avoid the 2.5. Thanks again.

anthrax144

250 is a problem (albeit somewhat minor) but the 350 does not have that problem. Get a 350, you'll be happy you did!