XhyDra

iTrader: (8)

There's a few things I'm interested in regarding the overall precedure. From what I know Lexus technically breaks in the piston rings at the factory, how will this be done at the dealer and what exact procedure is to be done. As far as I know this is the most important thing when it comes to breaking in a new engine, the way piston rings are seated.

Next if what the last two pages of this thread have mentioned regarding the space needed to reduce or eliminate the carbon issue, will this create or reduce overall power in the vehicle. I'm trying to get my hands on the technical sheet for this procedure, but if anyone has had this performed or is currently getting it done please post up any technical info on your work order sheet. Thanks.

APynckel

Won't atomize the stream, and anything pre-throttle body won't have enough vacuum at idle to keep it from puddling.

APynckel

Honestly, a factory meth injection kit would probably keep the valves clean enough under random WOT conditions the cars would see.

hades281

Who works for Lexus?? Can anyone help us out in getting a copy of this TSIB??

chikoo: I don't know if that is the best method to get a chemical cleaner to contact the valves. The BG inject-a-flush apparatus uses an air compressor and a nozzle, along with specialized cleaning products. We really need a boroscope to do before/after views to see how well it works on our engines. BG Products did it themselves on a new Ford Taurus to prove that the cleaning solution works, and posted videos of the same procedure being performed on a VW 2.0T engine which is notorious for carbon buildup.

freeflight: A dealership engine overhaul, which is what the rumors about this TSB allude to, would be big bucks. It's also one of those projects where, depending on mileage, you start saying to yourself... "While you're in there, lets replace A, and B, and C" (things like timing chain guides). Keep in mind that at this point the engine would need a thorough decarbonization. If you pull the valves, you'll put new valve guides, etc, etc.

Lexus is better off doing factory engine rebuilds and just swapping your engine for one redone and tested in a factory setting. Other manufacturers have done this.

XhyDra: Keep up the good work, I hope you find a way to get this TSIB

APynckel: Agreed, a factory injection kit of some type would be an easy way to solve the problem I think. They can size the reservoir to last more than 5000 miles and have it refilled at every oil change.... but I don't know how much fluid we're talking about here.

chikoo

I think it will atomize just well because this is not going to be gravity fed. It will be pulled into the air hose due to the air suction (vacuum) created and will create a fine mist through the syringe opening when it mixes with the air stream..hopefully.

Like this..

APynckel

Yea, that device you just showed me, is called a venturi,

chikoo

I know...but not sure if there is enough pressure in the air hose to create the mist

APynckel

It's not pressure in the hose you need, it's pressure drop across the injection point.

chikoo

Thanks for the correction my friend. It's been a long time I have used my engineering lingo now.

XhyDra

iTrader: (8)

So I came across a little more info regarding the procedure, it appears that aside if pistons and piston rings, the valve springs, valve lash adjusters and valve spring retainers are also replaced. And Lexus is looking at this on a case by case basis where the dealer has to perform a certain test and Lexus approves the entire overhaul. Now I'm not exactly sure of what's required to have this done but I'm sure those of us with extended warranty and a history of top end cleanings should be good to go. This isn't going to be a recall campaign but only a powertrain covered issue.

lobuxracer

iTrader: (2)

L-SB-0068-11 August 11, 2011. Pretty straight forward, rebuild the engine with new pistons, rings, Valve Springs, Valve Lash Adjusters, and Valve Spring Retainers (if applicable).

Honestly, it doesn't make economic sense unless the supply chain is so low they can't afford to use new short blocks for this.

hades281

lobuxracer: Is there a VIN range or model year mentioned in the LSB for affected cars? Is there a cause or reason listed (such as low tolerances, inadequate piston ring tension, carbon buildup, etc)?

APynckel

A new shortblock is unecessary as a fix, unless they take the shortblocks from the ones already replaced, and reuse them. It would be too expensive to replace the shortblock on that many cars when all they really need to do, is add a $500 meth injection (or 2ndary plenum mounted fuel injector(s)). Just something to add a solvent to break down and clean the system.

FROSTYIS

Word

Also definitely do not let your car go 10k without a oil change in between

lobuxracer

iTrader: (2)

No, actually it would be much simpler and cheaper to replace the short block with factory assemblies instead of having a whole lot of machine work done to the existing unit by a local machine shop where prices and quality are highly variable. Of course they're going to use the old ones as cores, they'd be idiots if they just tossed them.

Solvent isn't the issue because you're not going to be spraying at a time when the carbon build up happens. The carbon build up is a result of reversion while at part throttle with the cam timing performing an EGR function. It's going to take more than meth or water on WOT to clean these things reliably, and the vast majority of owners are terrified to go WOT anyway, so the likelihood of putting an injection system on the engine and actually having it work in the field is pretty close to zero.

See this post for the what and why this problem exists.