gsrthomas

iTrader: (1)

So what are the instructions to this TSIB engine cleaning from Lexus? I have heard dealer giving quotes of about $900 which I think is outrageous.

Better to get the proper instructions from Lexus or a DIY from someone so people can do this routine maintenance themselves if needed. Better then paying Lexus $900 doing it.

Has anyone used seafoam in their IS250?

RA030724

iTrader: (1)

I've used Seafoam as a gasoline additive per the instructions on the can. Menard's has it on sale here every so often for about $6 a can. Never "force fed" it to my car though. Course I've got 21K on mine and not had the idle issue yet. But I also declined the "short bus" pedal and ECU reprogramming to go with that. (I'm bright enough to follow instructions and clip my mats in.) I have also used the official Toyota Fuel Injector Cleaner that you put in when you have a half tank left and then run down as far as safe. I've used that on all our Toyota/Lexus cars over the years.

Thinktwice

I believe the high dealer costs are simply due to the amount of labor involved. You're absolutely correct, if you can DIY that will always save money since you wouldn't be paying someone else to labor. That pretty much always goes without saying. But in the end it's the convenience factor for most who aren't DIYers.

msb028

iTrader: (1)

Cleaning the throttle body myself seemed to help me for a bit - but the engine shuddering/idle issue still happens every once and a while.

Got a quote from a reputable local shop in town for about $400 to do the top engine cleaning service. I printed out the TSB instructions to show them exactly what I needed, and the tech was surprised at the thoroughness of the procedure.

A1 - He also though it was pretty funny that they say specifically that the GM upper engine cleaner is what should be used.

The shop I went to actually uses the same GM cleaner to do carbon cleanings, but they generally do it through a vacuum line. He suggested I try doing this method first because it would be a heck of a lot cheaper, and then I could always do the full cleaning if it didn't seem to help.

I mentioned the Seafoam, but they seemed to think that the GM cleaner was better.

RA030724

iTrader: (1)

Is everybody sure this is related to being a direct injection engine? Have all the cars that have this problem had the brake pedal reprogram mod added to the ECU? I ask because more and more cars are direct injection including the new Buicks. If it is a bad design, then why are others using it? Plus I have 21K and have not had a problem so far, though I do run Toyota EFI Cleaner once a year in the gas tank. I have not had the floormat/brake pedal/ECU reprogram mod done as I am bright enough to secure my mats and know where my ignition switch is. Just wondering.

msb028

iTrader: (1)

Hmmm....Interesting thoughts

I have 65K currently - problems began at around 55K. It doesn't seem like 21K has been long enough for you to start experiencing a carbon buildup problem.

This issue for me began well before I had the floormat/brake pedal/ECU reprogram mod (which I did only recently).

RA030724

iTrader: (1)

I thought I read somewhere in this thread that 18K was the average for onset of this. Still I can't believe enough carbon can build up to overcome the force of the valve springs to keep the valves from closing.

Kurtz

iTrader: (1)

How in the world would a brake override have anything do with the problem?

(and if it were it wouldn't explain why 350s, which got the same ECU update, do not have the problem... that alone points very strongly to it being a DI issue, since the 350s also have port injectors that let fuel clean the valves while 250s do not)

Further- if you read the thread- a number of other DI engines from other makers have the issue too (VW and Audi among others were mentioned I believe).

nabbun

I'm glad you had a pleasant experience with Lexus of Englehood. Last time I took my car there, I caught the porter boy blasting the stereo system in my car like it was a night club. I heard the music from the waiting area and went outside to investigate. So, I haven't gone there since. This was before they moved the service dept over to across the street.

As for staying on topic, I think I've felt the rpm drop/vibration thing once or twice. I've had my 07 2IS since March of 07 and it has about 33,000 miles. I drive it like I stole it half the time and the other half is all highway miles. I'd like to know if there is a solid solution coming out that works 100% anytime soon or if it has to be the TSB. My warranty is out and I don't wanna pay like $900 bucks lol

XhyDra

iTrader: (8)

I'm almost betting that if we had one additional fuel injector directly spraying into the intake port it would completely counteract this problem. The only application I can think of that does this is the RGM & Arma Speed superchargers. Now if only I could get my hands on one for a reasonable price.

That would explain the massive gains in HP too. I believe the IS250 has 6 injectors while the IS350 has 12, correct me if I'm wrong. I did read somewhere that even one injector spraying directly into the intake port would render additional HP.

I'm tempted to try a small solution with a nitrous oxide kit, provided that it comes with an injector. Time to experiment...

To add to injury last night I revved the hell out of my engine for kicks and... Yes you got it right misfire codes "check engine". It had been running rough for the past few weeks, I'm blaming gas prices, I've been taking it easy on the throttle. So I resorted to turning it off and back on to reset the safe mode, and ran it on 3rd gear at 60mph for 5 min. That settled the idle and it's normal now, for how long? Who knows. It's about to be one year since the last top end cleaning. Around 27k since the last service, this is frankly getting too costly to be regular maintenance and DIY seems to be the only way out.

So let's hope there's a better solution. My proposal is do one more top end cleaning and then install a wet shot of nos kit with the additional injector to the intake port and see where we get from there. Of corse a conservative shot.

I dare say I might just install a direct port nitrous injection system

Kurtz

iTrader: (1)

I'm unclear how you think adding more fuel would magically render added hp... (since the car is getting plenty of fuel from the OEM injectors).

The only reason the ARMA kit adds fuel is because the supercharger is forcing in MASSIVELY more air than the engine would normally ever ingest.

It's entirely possible it'd avoid the carbon issue if it was in the right place I suppose, but you'd need some way to dial back the fuel added by the direct injectors if you weren't otherwise bumping the oxygen content or you'd be running pretty rich...O2 sensor feedback might "fix" this in closed loop mode after running it a while though...(or your nitrous idea would take care of of course... but then the problem is do you need it constantly (or very frequently anyway) flowing fuel to clean the valves like on the 350... or would just the once-in-a-while shot do it?

CCJ22

iTrader: (26)

I thought that randomly hitting the rev limiter while driving helps in clearing out carbon?

RA030724

iTrader: (1)

First, the ECU program would be different for the IS250 than the IS 350 due to the different parameters and functions that are monitored and adjusted in a 250 vs 350. And working in IT, I know that anytime you change a program's code to fix or add something, you take a chance of affecting something else - maybe not even remotely connected to the fix. I have read here that the symptoms show up while stopped with the brake on or while braking hard. That makes me wonder if the mod, which gives the brake priority over the acelerator, has anything to do with the problem. Like I said, I just can't believe that enough carbon could build up on an intake to keep the valve from closing reliably. And if it didn't, I would think the resultant backflow of gases would clean the surface almost immediately.

XhyDra

iTrader: (8)

That would be the case if it was only being affected in one area. Hitting the rev limmiter wouldn't be the solution though seeing as I've done that only to throw the car into check engine because of misfires. The only temporary fix I've done that yields a result is running the car in 3rd gear at 60mph for a few minutes. That alone isn't going to clear any if the carbon behind the valves or through the intake manifold.

The ECU update has absolutely no effect on this issue. I'm one of the few that refused any involvement in having the pedal safety recall performed. Same issue has occured with my vehicle when braking. I'm sure some of the tech gurus can further explain what happens when you come to a complete stop, timing etc.

Kurtz

iTrader: (1)

Except folks had the problem before the brake override ever happened... and plenty of non-lexus DI cars have the same problem without such a recall... (and "if brake is pressed when accelerator is pressed and speed is over X, ignore accelerator" wouldn't be different code between the 250 and 350 either for that matter... further the code wouldn't be doing anything at all if the accelerator wasn't pressed at the time)




It's like you threw a dart at some random thing and blamed this on it despite it not making any sense to do so.