BinaryJay

I am getting my car back from Lexus this afternoon. For those who aren't aware, I took it in because my idle was bouncing during cold startup, sometimes wavering during driving and causing vibrations. I had no codes.

I don't have the TSIB details but what I was told was that they performed the following according to some TSIB:

1) Replaced ECU
2) Replaced two O2 sensors (I am assuming upstream ones)
3) Changed Oil (not sure why this would be part of the TSIB for the above, but they said it was. ???)

So if you're having issues like that, but don't have any codes, your dealer still might be able to help. Has anybody had this TSIB done, or can point me to any TSIB document that recommends the above being done?

Thankfully all was done under warranty. I bet they charge two arms and two legs for an ECU on these cars.

IXI187IXI

iTrader: (3)

hmmm interesting. thats good to know because i bet those ecus arent cheap either!

spine911

iTrader: (4)

ECU, and O2 sensor replacement is the "initial fix".... some fix went as far as replacing the entire short block.

Keep your fingers crossed.....

it might/might not eventually solve the erratic idle caused by carbon build-up.

refer to my old post #45, #57.

https://www.clublexus.com/forums/gs-...m-spike-3.html

helpmeout1

My car can idle between 1800 and 1000 for up to 15 minutes on a COLD start. My front brakes completely lock up when the idle is this high, and the rear wheels continue to spin. I have also been recently experiencing intermittent short spurts of rough idling.

When a Lexus Field Tech ran scans on my 07 GS350 he pulled an error code that said something about ECU. The Field Tech explained another error code to me, but said nothing about the ECU error code that I saw.

I mentioned the error codes to my local dealer when I took my car in for service. The dealer had my car for a week, said they could not find any error codes, and said the Field Tech must have cleared out the error codes.

I am still experiencing the braking and idle issues.

spine911

iTrader: (4)

Carbon build-up at work.....

^refer on the above link for details.

helpmeout1

I do have quite a bit of carbon build up on the exhaust tips.

Sad thing is.....I only have 26k on my car but have soooo many issues.

BinaryJay

I was told that it is much better now... but they kind of attached a caution to that saying "there is still a little bit of bounce emphasizing that it's slight but it is within what we consider normal comparing with other GS's we have on the lot". I have no idea what to expect after I get it back but I guess if I'm not satisfied there are more things they can do if I'm not happy with the results?

You said after they did it for you, that you'd be observing... did you find that the O2/ECU thing did the trick in the long run? I think I will take the car out for a few italian tune-ups afterwards...

raptl1985

What year is your car?

BinaryJay

It's an 06 AWD. I also find myself wondering about the parts replaced under the TSIB. Is it because they have "gone bad" or because they were redesigned?

Bavaria

Would there be any benefit to using specific gasoline brands to prevent or mitigate this situation, or is it a 'genetic' defect?

BinaryJay

My workorder states:

Cause: No readings present from O2 sensors with techstream
Correction: Perform TSB #2258

Parts:
2 x Sensor, Oxygen
Computer, Engine
Valve, PCV (Replaced PCV valve too? OK)
Lube Kit

Took it for a spin around the block but had to come back to work, seems fine to me... time will tell.

Thanks to Tony for finding and sending me what appears to be the equivalent TSIB for Lexus USA. It seems that Lexus USA no longer gives you a free PCV valve for this ...

Explanation of what was done:

"The oxygen sensor type has been changed from a planar to a cup style. The Engine Control
Module/ECM (SAE term: Powertrain Control Module/PCM) logic has been modified to address this
condition and accommodate the new oxygen sensor. Refer to the following repair procedure to
address customer concerns."

So the oxygen sensor has been redesigned to a different type, and the ECU has been changed to accommodate the new oxygen sensors.

dunnojack

so what can a person do about carbon build up?

any way to prevent it?

BinaryJay

Well... there are fuel additives and such like the infamous Seafoam, Techron, etc. There really isn't a whole lot of proof that using these products is anything but snake oil, there are reports out there on both sides of the fence.

Equally unproven are engine cleaning systems that you can have done at shops like Motorvac (older) and Terraclean (newer). I also have no idea how much good or bad these do, but given what I know about this car now I'm tempted to try terraclean sooner or later.

I don't really want to do anything on a fresh oil change though so I'll probably leave it until just before I plan to change the oil again.

My favorite, most fun and least expensive folk cure for buildup is the italian tuneup... which is basically taking the car out and going WOT repeatedly for as long as you think you can get away with it. Hopefully burning off and blowing away deposits in the process. Supposedly it's called this because exotic italian cars were (are?) particularly prone to this kind of buildup and need to be driven hard once in a while to operate properly... could be total urban myth.

spine911

iTrader: (4)

1). Regularly using High Octane gas (91+), in some states 93 is available.

2). Chevron Techron - same additive exclusively used by BMW, Porsche ; independent studies showed that Techron when used regulary had the SAME results compared to more expensive bench injection cleaning services (like BG, ..etc..etc). I make it a point to drop a bottle every oil change on all my cars. If you feel you need a more concentrated dose, add a bottle on half a tank instead of a full tank.

3). Spirited Driving keeps carbon deposits from forming....drive it like an auto-bahn stormer.

4). PCV valve regular maintenance.

....i managed to put 3k miles since they replaced my ECU, 02 sensors; i asked Lexus to perform an oil consumption test as well...ill report back on what happens...my wife had been driving my GS since, and haven't had the time to really observe the GS...the C4S keeps me distracted.

TWong350

iTrader: (8)

Use good fuel and always premium grade. Most importantly, open it up every so often. The main reason for carbon build-up is a poor PCV system. Nothing can be retrofitted to make it better short of an external catch can, which no one on this site will likely do. Opening up to WOT every so often can theoretically help the motor take a deep breath and spit everything out.

What my buddies and Toyota and Lexus say? Nothing can be done about it but this and even at that, it'll still happen!

Perhaps for those that always wanted to learn how to take apart a motor...here's your perfect chance! LOL