Just took my car in for the brake dust TSB and check VSC. The VSC ended up being a loose gas cap which I told the dealer. The CEL went off before I brought it to them but I told them about it anyway. So they call back and tell me VSC was related to this carbon build up. The car has 34k on it and they want to run this fuel injection or something threw it to clean it out. It costs around $200 for this service. He said Id need this dont every 30k or so. Can this cleaning be done by myself or another independent mechanic? Paying $200 every 30k isnt a big deal but if I can get it done cheaper then why not. Ive read here and there about this issue but dont fully understand it. What do you guys think? I want to stay on top of my maintanance so the car doesnt break down.

Also should this cleaning be under warrenty?

 

Its a top end clean and it remove some of the carbon on valves,pistons,injectors,maf,t/b plate. Its mostly due to the fuel we use on the car so try to 93octane and top end clean about every15k. Know if it realy bad and cut off on you then its a warranty thing and can be covered.

 

FYI...there is a TSB for this on the IS250, but not on the 350...search for "carbon build-up" and you will find a huge thread on this...

 

thanks, just found it. I just called the dealer back and ask if its covered. He said no thats its more of a maintanance item. But im bringing the TSB to him

 

I use 93 octane and have had no other symptoms such as rough idling relating to carbon build up. Just the random check VSC but my gas cap was loose. Retightened it and a couple days later it went away. Im just wondering if the dealer is trying to work me over by saying he saw a misfire code when he scanned it. Should I just hold off on the carbon build up engine cleaning until I get a CEL or feel rough idling? Or should I just get it done anyway being im at 34k?

 

If the code was truly related to carbon build up then the dealer should honor the TSB at no cost to you. This only applies to the IS250.

Or they could be telling a fib and trying to sell you something that you don't need. This would be the case if you have no symptoms or an IS350....

I did the TSB myself as I was curious and didn't think that my dealer would cover it since I have headers etc... However, I never did ask so they might have done it for free. idk? The material cost is low but there is a lot of labor. After the TSB, I had a Toyota dealer perform the BG induction service since the TSB doesn't directly clean the backside of the valves. I used Toyota as they are located near many other automobile dealers. So there is more competition for maintenance work and hence much cheaper.

 

The carbon deposits come from the fuel formula, not the octane rating (we should all be using premium anyway, its on the gas cap!)...every engine will experience carbon build-up, but the 250 motor seems to be very sensitive to this...

Just read the TSB, it will tell you what symptoms prompt this TSB...if your car has some of them, then they should perform the TSB, but if you don't have any symptoms, then they don't have to do it...

 

Just back from talking to the service manager. I was honest and told him I have no symptoms of the TSB except for an engine misfire that came up during a scan. Other then that my CEL went away when I retightened the gas cap. He just advised me to come back if I get another CEL. He said like you stated the deposits come from the fuel and it isnt a design flaw in the engine. He said I will have to pay for the engine system flush which should remove alot of the build up. But out of courtsy if it doesnt remove it all he will take the top off and manualy clean it this one time for free.

 

^^ Nice...sounds like you have an understanding service manager who is actually listening to you and willing to help you out...

 

The carbon buildup problem on these Lexus engines doesn't have much to do with the fuel. It's actually more to do with lack of fuel. The root cause is EGR and the dry intake valve design.

You can bet that Lexus will not produce any more engines without any port injectors after this generation. Luckily, it seems that it takes many many miles before it actually becomes a problem so overall cost of ownership doesn't increase dramatically even if you have to pay hundreds every 50,000 miles or so for a proper top engine cleaning. A more frequent regiment of induction service may or may not keep it in check.

What exactly is this engine flush service they are trying to sell you? There are many types that have been floating around the snake oil market for ages.

 

If the dealer say it a maintenance service ask him were in the owner manual it state it. Let I'm prove it has to be done at 30k service. Other than that it s well know tsb and should be done free just like the front brake pads.

 

Exactly. You can run the best fuel on the planet and it won't matter since it will never touch the parts that get the carbon buildup due to design.

 

OP there is no reason why you should be paying money out of pocket to fix something that is under warranty. No where in the Lexus manual does it state "top end cleaning" as part of routine maintenance. Your service advisor might be playing the smart game with you but it's part of his job to sell you a service not give you one for free.

Contact Lexus corporate regarding this issue, have them look up
your service record and point out the CEL due to a misfire caused by carbon build up. They will build a case, call you back and have you choose your dealership of preference to have this service done. The actual service is not likely to be the one you are being sold.

Note that the dealership will usually refuse performing this service as it will want actual symptoms and they usually disregard the cylinder misfire, I've been there and did the protocol. Let us know your experience with this.

 

I called corperate earlier this week and complained about it. They contacted the dealer and got back to me. They said the dealer will cover the carbon build up cleaning. Told me to come back in if I get another CEL. Corperate was very helpfull

 

It's good to know that things went seemless. If a car with low miles still under warranty is having check engine issues, there's a high chance that it shouldn't be happening and you shouldn't be getting charged to have it looked at or fixed.