Remix919

I've noticed on a few occassions a slight hiccup or hesitation while idling in drive. It happens very rarely and all that happens is the tach seems to drop a bit, down to 500rpms or so and the engine feels like it's about to stall for a split second, then just goes back to normal. Never noticed this while in park, only while idling in drive. Any idea what this could be?

knbnguyen

Carbon build up, you have a 250?

Remix919

Yea, 2008 IS250 AWD with 57k miles

knbnguyen

Do a search on carbon build up, it is a common problem for the 250

axis77

carbon build up my friend, I have a 2007 IS250 at about 58k i REALLY noticed this same situation..always brushed it off before. but one day my car would just not start just keep clicking like it needed gas..anyways lexus got a hold of it did some test turns out my pistons got damaged cause of this buildup and 2 weeks later i had my pistons rebuild and the whole top half of engine redone..$12k job done for free from lexus.

Gr33nHrn3t

iTrader: (2)

You can always seafoam your car. I have done it to mine and it got rid carbon build-up. I put 1/4 of the seafoam into the fuel vacuum line and the rest directly in the gas.

bob4256

iTrader: (17)

https://www.clublexus.com/forums/is-...d-threads.html

diablo1714

iTrader: (4)

Thx, Bob4256. I believe this answers my question that MY '10 was the last known year to have the Piston/Ring problem

KillaIS250

iTrader: (1)

Not true. There are some members here that have said they are seeing it in the newer models even. The only thing that really changed was the design of the pistons. I had the "new" pistons put in my car and still had the carbon build up issue. We wont really know completely til the 2011/2012 MY owners put more miles on there cars.

isbbq

iTrader: (13)

dealer replaced all pistons for my 07 is250 4 monthes ago.....problem still there but dealer check didnt find any misfire

diablo1714

iTrader: (4)

TY, Killa. Yes I understand that the Carbon issue continues. It was the Piston/Ring issue fixed in 2010.

While I do go WOT a few times a week, well simply 'cuz it is fun, it also 'may' help with the carbon issue...but no one can say for sure.
I guess there will be the BG treatment and/or Seafoam treatment in my future !!

KillaIS250

iTrader: (1)

I'm in the same boat as you. Replaced all the pistons and everything, still had issues with carbon build up. After 1k miles, carbon build up was already occurring. Dealer sent data/pics off to Lexus corporate.....corporate said "no further actions to be performed at this time". Pretty damn upset, i'm doing my research before contacting corporate now to figure out a compromise.