Carbon Build Up

[chris_e_fresh]

hey lexus homies,

i just took my 2006 is250 for its 90k service at ultra tune north ryde - it had a slight hesitation when slowing down and dropping revs and what so, i read up on this on the american forums and it lead me to believe i had some carbon build up - i spoke to the boys at ultra tune and they have heard of it before. They cleaned the throttle body and whatever else they had to do. it was at a minimal cost.

The car runs like a dream now - just thought id share my story to you all to get it cleaned because the difference is amazing.

[ldc]

Mate, would you mind telling me how much it cost for this service?

[Bluey]

Hey Chris

What fuel are you using? Do you tend to use the lower 91 or 95RON or the 98RON fuel.

[LEX51S]

Did you get the throttle body clean at lexus? if so how much??

All it is is basically oven cleaner sprayed into throtle body left for ten mins and then start the car with full throttle and thats it?

I had the same problem chris explained. Fuel may pay a role in this but as i only use 98+ I did the throttle body clean and happy days!!

[chris_e_fresh]

Mate, would you mind telling me how much it cost for this service?

it cost me around $500 - i didnt get the spark plugs done as they are $83 each and lexus couldnt deliiver them in time so it would be like $1000 if i got the plugs done - i'll get them done next service of if it starts to play up

lexus sydney city wanted 1350 or 1550 from memory

Hey Chris

What fuel are you using? Do you tend to use the lower 91 or 95RON or the 98RON fuel.

allways 95 sometimes if i forget i put 98

Did you get the throttle body clean at lexus? if so how much??

All it is is basically oven cleaner sprayed into throtle body left for ten mins and then start the car with full throttle and thats it?

I had the same problem chris explained. Fuel may pay a role in this but as i only use 98+ I did the throttle body clean and happy days!!

no i got it done at ultra tune to be honest i think it said like $40 it wasnt expensive at all ( the receipt is in the car and im lazy to walk down to check it lol

im not sure what they do - the boys there have been servicing my lexus for about four years i cant recommend them enough and i spoke to them about it and did what they had to do

[jac80m]

it cost me around $500 - i didnt get the spark plugs done as they are $83 each and lexus couldnt deliiver them in time so it would be like $1000 if i got the plugs done - i'll get them done next service of if it starts to play up

lexus sydney city wanted 1350 or 1550 from memory

Just on the plugs, there is a Denso equivalent which my awesome Lexus tech told me about, ordered them from eBay us, and delivered for the price of 2 plugs from Lexus. Msg me if you want the part number and i'll find it for you.

Cheers

[jac80m]

Just on the plugs, there is a Denso equivalent which my awesome Lexus tech told me about, ordered them from eBay us, and delivered for the price of 2 plugs from Lexus. Msg me if you want the part number and i'll find it for you.

Cheers

[ldc]

Mate, would you mind telling me how much it cost for this service?

it cost me around $500 - i didnt get the spark plugs done as they are $83 each and lexus couldnt deliiver them in time so it would be like $1000 if i got the plugs done - i'll get them done next service of if it starts to play up

lexus sydney city wanted 1350 or 1550 from memory

Is that the going rate now for a tune up?

My car's done half the amount of Ks so do you think i should get it done i haven't notice any hesitations, just rev fluctuations abit and at started the revs sometime don't go down when it's warmed.

[Subby]

Did you get the throttle body clean at lexus? if so how much??

All it is is basically oven cleaner sprayed into throtle body left for ten mins and then start the car with full throttle and thats it?

I had the same problem chris explained. Fuel may pay a role in this but as i only use 98+ I did the throttle body clean and happy days!!

Lex51s,

Would you be able to provide some instructions on how to do this ourselves?

Thanks

Subby

[LEX51S]

Guys i found this post you might be interested in!! Its for an RX but the skills are transferable. Although i didnt get this involved in the driveway

Hello Everyone,

I know IACV has been a huge topic on the forum and I have found various pictures in the RX forum and ES forum on the idle air control valve (IACV) or as others call it the idle speed control valve (ISC). However, I have not found a "step by step" posting to date which definitively shows how to clean this thing so that my car stops giving me idling problems.

Symptoms I have had included:

- low and rough idling that would cause the car engine to start shaking after starting the car

- this eventually got worse to the point that when I start my car, it would not idle unless I gave it gas

- idling problems for me tended to occur more often after my engine was warm or had been sitting in the sun

I hope these series of postings help you fellow LOC members out there. You've certainly helped me in the past so here's my two cents at this common problem. Additionally, the instructions I give are the way in which I have cleaned it myself. As you go about and attempt this, you may find better ways to do so. Please add and refine my instructions/terminology as needed. I am not a professional. I've only changed my oil, air filters, and conducted minor maintenance previously. The bottom line is that if you have the right tools, you should be able to do this. This discovery/ cleaning took me about 2 hours to do cause I ran into problems and there were major steps left out in previous postings that I’ve encountered read. The next time I do this, I believe I can get this done in about an hour or less.

Tools Needed:

1) Tightly fitting Philips Screw Driver

2) Carb cleaner that is O2 sensor safe (I've seen CRC. I used Valvoline Carb Cleaner)

3) Locking Grip Pliers (definitely helped me remove the factory tight screws)

4) Small brush for cleaning

5) Towels for cleaning

6) Pliers (help removed brackets holding the hoses)

7) Latex gloves helps with limit the messiness.

* I used the same gasket and did not replace it. No problems found.

1) Remove the hose that comes from the engine/motor that connects to the air intake hoses.( Hose is below in red – we’ll refer to this as Hose A) When you pull back the rubber hose covering, you will see that a metal bracket is holding the hose pretty tightly in place. Use the pliers to clasps the two metal pieces together to loosen the bracket and pull the hose loose. You can also do this by hand if it’s easier for you.

2) Upon removing the hose, you will want to remove the two air intake hoses. Loosen the three screws above in green and remove the hose. Below is a picture of the intake hoses removed.

3)After removing the intake hoses, I opened the lid to the air filter and moved this to the side of the car to create more working room. I believe there are two clips on the right holding the lid in place. Just pop the two clips and move the cover to the side. I also took out the air filter and temporarily moved this to the side.

4)After removing the intake hose, the throttle body/IACV/black electric coil is revealed. At this point, I removed the black electric wire from the black coil. Once the electric wire is removed you can remove the black coil from the IACV by removing the two screws. Note, the screws are factory tight so use a tight fitting screw driver to remove the screws. One of my screws was partially stripped from the dealership’s work, so I had to resort to my locking grip pliers which helped out tremendously. After removing the two screws, the black electric piece pops right off. When the black electrical coil is removed from the IACV, it exposes a small pencil sized metal stud. You will also notice a washer that sits on this stud. Don’t lose this washer. Take it and put it aside so it doesn’t fall off when you continue on in the next steps.

5)Additionally, I removed the hose coming out of the IACV. We’ll call this Hose B. This hose can be removed in the same manner by clamping the bracket and pulling the hose out. You will see that the hose is removed below. Below are pictures of before and after.

6)Here is where the fun begins. I initially attempted to remove the four screws attached to the IACV at this point, but found that after an hour, this would be nearly impossible to remove considering the location of the screws were in an extremely tight spot. The only way I would be able to remove the IACV is to remove right throttle body. Not as tough as it sounds. Three screws need to be removed to accomplish this. Again, be careful when removing the screws. Also you will see I removed another electric plug and I also cut a tie wrap. Once you complete these steps, the throttle body/ IACV comes out pretty easily. Note when you remove the throttle body, there will be one LAST hose connected to the IACV. Be careful when you remove this hose as radiator fluid may spill. Some of my fluid spilled out so I just refilled my coolant after I was done.

7)Below is a picture of the bottom view of the IACV. You now can EASILY remove the four screws connecting the IACV to the throttle body . In the picture below, I have already removed one of the screws.

Once the four screws are removed the IACV and throttle body separate. Now you can clean both of them with your carb cleaner, brush, towels, cotton swabs etc…. Picture here is before I the cleaning with all the muck inside

Pictures after I cleaned the IACV and throttle body

This last picture is the post throttle body cleaning

8) Once you are done cleaning, just put back the throttle body/iacv the same way you took it off, and put everything back in reverse order. Ensure the gasket is in place. Also, ensure you put the washer back on the electric coil. Make sure you place hose A & B back and ensure the electric plugs are back in their original position. Once these things are in place, then it's all about putting the air filter/hoses back and you are good to go. If you have lost any coolant, make sure you refill it to a safe level.

After completing this cleaning, my car starts up without any problem and idles as if I just purchased the car brand new. Replacing this at a dealership would have costed me $300-400 easily. Let me know if you have any questions. Cheers (Also, I tried to post these as separate replys, but the software combined all my replies into a single reply and did not keep them separated)

*Edited the posting to have the pictures follow step by step in sequential order*

[Subby]

Thanks a ton, Lex51s - much appreciated

Subby

[philliphs]

Mate, would you mind telling me how much it cost for this service?

it cost me around $500 - i didnt get the spark plugs done as they are $83 each and lexus couldnt deliiver them in time so it would be like $1000 if i got the plugs done - i'll get them done next service of if it starts to play up

lexus sydney city wanted 1350 or 1550 from memory

Hey Chris

What fuel are you using? Do you tend to use the lower 91 or 95RON or the 98RON fuel.

allways 95 sometimes if i forget i put 98

Did you get the throttle body clean at lexus? if so how much??

All it is is basically oven cleaner sprayed into throtle body left for ten mins and then start the car with full throttle and thats it?

I had the same problem chris explained. Fuel may pay a role in this but as i only use 98+ I did the throttle body clean and happy days!!

no i got it done at ultra tune to be honest i think it said like $40 it wasnt expensive at all ( the receipt is in the car and im lazy to walk down to check it lol

im not sure what they do - the boys there have been servicing my lexus for about four years i cant recommend them enough and i spoke to them about it and did what they had to do

Just $40 for a throttle body clean? If it's that cheap, I'm planning to do it soon as I think my car is acting up as well

[fatjoez]

proper carbon buildup clean will be more than $40

The ones i've seen done on Audis are intense.

The entire engine is opened up

[philliphs]

Probably true. Carbon build up is common in direct injection engine. I've seen in audi's and VW's forum that they have huge carbon built up on valves, but that's because of some oil hose problem that causes the oil to get back and get burned or something like that. I've recently gave my car a go with ultratune carbon cleaning. They did not open the engine, just spraying fluids through the intake while the engine is running. On IS I think it should clear most of the problems. Cost me $110. Now the hesitation is gone and you can feel the engine is really smooth and you can barely feel the engine vibration from the cabin.

[fatjoez]

@philliphs was that for is250? or is200

My 2007 is250 has 111,000km on the clock perhaps it'd be worth a go.

On a slightly different note.

Does anyone know how to get rid of the cambelt noise or whatever it is?

[philliphs]

IS250. sorry haven't change it in the profile. Mine is 2006 IS250 on 75,000km mark. It was worth doing.

[unco]

Sorry to dig an old thread back up but does anyone know if Lexus Australia have taken any action on this like our friends up in the USA?

I have been having issues with my 2006 IS250 with the following error codes:

P0306 (Cylinder 6 misfire)

P0158 (O2 Sensor Circuit High Voltage, Bank 2 Sensor 2)

I took my car in to the dealership and was told it was a carbon build up issue and that it would cost a bucket load to pull it apart and fix.

Seems people in America have been sent letters and had theirs fixed under a 9 year unlimited milage warranty for this issue.

http://www.clublexus.com/forums/is-second-generation/655541-is250-carbon-build-up-csp.html

[philliphs]

I'm not sure if the warranty applies for Australia. I know US Lexus has better service. Most of the recalls they have there don't apply here. Maybe you can try to bring the copy of letter to one of the dealer, even to Lexus Australia. I cleaned my engine with just spraying in ultratune. Helped a bit, but the jitter still there from time to time, but it didn't trigger check engine light. To properly cleaned it you need to open it up, and scrap the grease. It is basically the same as BBQ grill build up. Degreaser chemical spray only does so much.

[Fanel]

http://www.clublexus.com/forums/is-second-generation/682989-the-oil-catch-can-experiment.html

This is interesting, worth checking out