Kurtz

iTrader: (1)

I'd certainly expect the extended warranty to cover engine internals, yeah.

Jeff Lange

iTrader: (1)

Honestly, I don't think there is ever going to be an actual fix. Carbon build up will happen in a DI engine without any way to clean the valves. Slowing it down is helpful, and doing an engine clean every now and then isn't the end of the world to me. I wish there was a better answer, but I don't think there is going to be.

Jeff

new.era.13

iTrader: (10)

i wonder if they clean the valves while replacing the pistons.

codenko

iTrader: (8)

I got the carbon build up TSB done a while back and my service advisor informed me that theres a new process now. my IS has seemingly developed a rattle during cold startup since then...time to take it back huh?

mrraider

I've been reading a lot on the subject lately, and it seems many makers, including Audi and BMW have had carbon buildup issues with DI engines. The solution seems to lie in proper in engine redesign to improve the flow pattern, coating the valves with anti stick compounds, and reconfiguring the EGR system to not allow carbon particles to blow back. In short, a whole engine redesign is needed. With all DI and Turbo DI engines being released, I expect a lot of people will learn more about this issue. I doubt your average Elantra or Focus owner will take well to a 1500$ top engine cleaning bill every 40k.

Interestingly, GM has had no reports of this issue in their DI Ecotecs and HF v6s.

autox250

Make sure your morning rattle is just piston slap and not the cam gears. Theres not much you can do for the carbon issue, the valves do get cleaned w the bulletin and the pistons have been redesigned w shorter skirts to adress the oil consumption issue

Jeff Lange

iTrader: (1)

Yes, with redesigned engines and components there will likely be progress made and/or even fixing the issue, but I don't see any of that happening to the 4GR.

Still, slowing it down is still a step in the right direction.

Jeff

Gryss

I would have to see it before I would feel comfortable making a real comment on it. Sorry. Was the pedal campaign done? that just changs the shape of the pad, and not how hard your have to press it, but I would look there first.

Marbles in a blender type noise heard on cold start sounds like a issue with the cam actuators. Not related to carbon buildup issues. There is a TSB out for those actuators. get it looked at.

chikoo

By Golly. I have figured it out.

Here is what happened:

Before I got the carbon cleanup job done, I was using regular 87 gas.
But after the cleanup I decided to be the good boy and started using Full premium gas.
Yesterday, looking at the high prices at the gas station, I was tempted to use the regular 87, and I did just that. As a result, this morning I have the engine is revving just as lightly as it did before.

Wow....

chikoo

The downside of this is that it does not pull strongly in the higher rpm ie above 3500...meh...

back to Full premium next time.

Gryss

Full premium EVERYTIME. the lower octane rating is most likely causing the car to ping and the knock sensors are retarding the timing to keep it from detonating causing your power issue, or lack their of.

Chevron 91 for life.

MBTC

You gotta be kidding me... how many folks here with carbon build up have been running lower than spec octane? Ever? And blaming Lexus no doubt. If that's the reason for engine problems you deserve whatever you got.

J3ffrey

So you are saying that 87 octane causes carbon build up? really?

MBTC

So you're saying you're incapable of interpreting such a short post without putting your own spin on it? Really?

I asked a question, I didn't state anything that was not dependent on the answer to a question. Learn the language before you try.

----
Update: Looking back at my post, I realize that I assumed you were trying to challenge me on a statement that I had not yet made and were being a dink about it. I'm now wondering if you were legitimately asking me if its possible that 87 octane could contribute to carbon build up. If that was how you intended the question, then I apologize for such a snarky response, but if my initial hunch was right then it still stands

KillaIS250

iTrader: (1)

87 Ocane in a high compression motor that was designed to run on 91+ octane is only going to make the Carbon Build up problem worse.