Hello, new to site. As a woman, I'd like to understand if the following maintenances are required as they are costly, esp. the last one: fuel induction cleaning, differential repair, and timing belt replacement. I have a 2006 SC430.

 

Sorry mam. Wrong section. Mods please move to the other section for SC maintenance. I cant from my cell phone. Thanks.

To answer your question. I would say yes, those are all very important things to have done on all cars, not just on Lexus. Differential fluid is iffy, depending on the abuse. I had a bmw and never changed it. Had over 197k on it. It was a 2002 330i. Good luck.

 

well now you are in the performance section but not the right model section (430 has its own section).

depends how many miles you have on it for the timing belt replacement.
If you are having no fuel issues and it drives fine, I wouldn't do a fuel cleaning on a 2006 model.
If the differential is broken maybe then repair it, but if it isn't then I would think that is also unnecessary they usually only need a drain and refill every 100k or so as preventative maintenance.

that being said, the factory service interval lists a whole bunch of unnecessary stuff that may or not prevent problems down the line, generally it is a bit overkill though, but If you always take your car to the dealer and want it to be complete service history wise which is important to some people especially with newer more expensive cars then you would want to do all that stuff for the history of it.

 

Fuel Injection (im assuming you said meant injection not induction) cleaning you DONT NEED. Every time i took my car to sears or Firestone they ALWAYS offered it no matter how old or how new the car is. probably just a promotion that the dealer/service station is offering. Unless your car is puttering for dear life or you are getting terrible MPG, then maybe, if not politely say no thanks and move on. A bottle of lucas fuel injector cleaner for $8.99 from the auto store would do no need to spend $200 on it

Differential repair/service you can probably do with out. replacing the fluid is one thing, but unless your hearing knocking, or grinding, then your fine. If your car drives fine no problem then pass.

Timing belt is important but make sure to inspect the belt your self before you replace your belt. Different car but i had a honda that went 200k with out ever replacing the timing belt and it drove like a champ daily. It is recommended to change it at service intervals but not required. I only do it if i have the money to do it but i would suggest to do it at some point. not everyone is as lucky to have a belt not snap on them

Some guys on here will tell you im wrong and all 3 of these things are important but the interval at which you change them usually is different per car. A person who drives hard daily may need these more than a person who is more conservative driver. In the end really Its all preventative maintence

 

hi young lady
question 1 how many miles on your car and what year lexus 430sc?

 

This is my two cents worth, most of it from the '06 SC430 Maintenance Manual:

Timing Belt – The timing belt is located inside the engine and is not visible unless a portion of the engine is taken a part. The ’06 Maintenance Manual says to replace it every 90,000 miles or 108 months, whichever comes first. Although a conservative time frame, I completely agree with this Manual, since the SC has an interference engine and if it the timing belt were to break, it could cause catastrophic damage to your engine.

Drive Belt – That is the belt visible to your eye when you view your engine. The ’06 Maintenance Manual says to inspect it at 60,000 miles for cracks or wear. Replacing the drive belt at the same time as the timing belt makes sense if it has not been replaced previously due to excessive wear.

Differential Repair - I assume this refers to differential fluid. I would have it and the transmission fluid inspected at the same time, at around 60,000 miles according to the ’06 Maintenance Manual. If you bought your car used or drive it really hard, then I would have both of these fluids inspected and/or changed earlier.

Fuel Induction Cleaning – This refers to fuel injection cleaning and is not necessary IMO. Nowadays most gasoline’s have many additives, such as Techron, which prevents deposit formation and also acts as cleanser for older deposits left behind by low quality gasoline. For peace of mind, there are many gasoline additives or fuel injection cleaners that you can add to your tank whiling filling it with fuel that will work just fine.

 

Agree with previous posters - Buy a bottle of Techron fuel injector cleaner at Walmart for $6.89 and add it to about 12 gallons of gas, then run that tank dry (well almost dry) before refilling. And don't be shy about getting it out into the country now and then for an Italian tune-up (translation accelerate hard to blow the cob webs out).

Rear diff fluid can be done every 50K miles if you plan to keep the car long range.

Timing belt is beneath engine covers and is not visible outside the engine. The belt is driven off the crankshaft and in addition to turning the camshafts (cause the valves to open and close) it also drives the water pump.

The timing belt itself never breaks on its own (almost unheard of). However, the water pump bearing can seize, or the belt tensioner or idler pulley can break and any one of these failures will cause the belt to break or fall off. Once the belt breaks the camshafts are free to turn on their own out of synchronization with the rest of the engine. The valves open so far that when the piston drives up out of time it will smash into the valves, causing $2k-$3K in repairs.

If you have the timing belt replaced at 90-100K miles, definitely get the water pump, belt tensioner and idler pulleys all replaced at the same time.

 

2006, 95K miles

 

Thank you very much!

 

Thanks very much!

 

SC43052,

I respectfully disagree with your assessment of the timing belt never breaking on its own and almost unheard of, unless you are saying that the timing belt rarely breaks within the given maintenance time frame of 90k miles or 108 months/9years. Toyota/Lexus/Denso builds a fair amount of conservatism into the maintenance time frame for the belt to be replaced and am agreement that it should easily last 90k miles or 108 months, but the life of the belt can vary:

"Life expectancy of the timing belt depends on many factors other than just mileage and age: (1) Weather plays a very important role, rubber tends to get hard and stiff when it's cold, with initial startup under this condition being very hard on the belt. If the vehicle is operated in warmer climate condition the timing belt will last significantly longer than a cold climate. if the vehicle was driven in a cold climate condition but kept indoors when not in use, initial startup will also be less severe, thus belt will last much longer; (2) Driving habits - the timing belt is under greatest stress at initial startup when the belt is cold and stiff. The belt is also under greatest load at the initial crank and initial pick up or acceleration, therefore life expectancy can greatly differ comparing a vehicle that is driven in the city as opposed to vehicle that is operating mostly on highway. The timing belt is under greatest load at initial acceleration and hard acceleration, which will put more tension on the belt causing it to stretch and fatigue thus shorten the belt's life; and (3) Contamination with oil and coolant on the timing belt can greatly affect life expectancy of the timing belt."

Simply put if someone bought a new SC and ran it hard all of the time, especially in cold weather and after initial start-up, it could potentially shorten the life the belt and/or cause harm to the water pump, tensioner or idler pulleys. Fact of the matter is, that if what you are saying is absolutely true, they wrote the maintenance manual incorrectly and that it should say to replace the water pump and pulleys at 90k miles.

I am in full agreement with you that when replacing the timing belt many other items such as the water pump and pulleys should be replaced at the same time.

 

tpaflgal, welcome to the forum.

I agree with most here that the timing belt should be changed out on your car if it hasn't already been done, along with the other items that have to come off in the process (water pump, idler arm, etc.). Fuel injection cleaning is not needed unless your car has glaring needs or was fed a lot of really bad gas for a while. (Not likely these days.) Differential service, just follow the service manual recommended intervals.

Enjoy! You've got great weather there in Florida to drop the top!

 

sixonemale,

Thanks for your response. You entirely missed the point of my statement regarding timing belt breakage.

Your response would have been valid had I said timing belts never break, so change everything else out and put the old timing belt back on and you are good to go, or if I had said 90K mile intervals are too short and it should really be 150K mile intervals.

What I said was timing belts always outlast the other components that the timing belt interfaces with, and other component failure is ultimately the cause of the timing belt failure, no matter when the other components ultimately break, be it at 70K, 90K or 200K miles.

I have no disagreement with changing out the timing belt at the recommended 90K mile intervals. My point was whenever you do change the belt make sure you get to the heart of the matter and change out the root cause of the system failure (the other components), whether that is at 60K, 90K, 110K or 150K miles.

Toyota refers to it as timing belt maintenance when they should really refer to it as timing belt system maintenance. Many if not most aftermarket "kits" sold contain all of the timing belt interface components as well as the timing belt.

My emphasis on changing all of the components is due to the knowledge that some clueless dealers inspect the water pump and other components to see if they should be replaced while changing out the timing belt. This borders on criminal negligence.

First, as you know, the major cost to changing the timing belt (which if the belt only is purchase after market can be as little as $50) is the labor to get to the belt. The additional labor to change the other components once the belt is removed as almost nothing, so the actual cost of the additional components is the incremental cost, which is small.

Second, if real world experience shows that the other components always fail before a timing belt, no matter the miles, why would you change out only the timing belt at 90K miles and expect all of the other components to last until the 180K mile mark, which would be the next scheduled timing belt change? PURE STUPID.

 

SC43052,

We both agree that due to the labor cost and being smart when it comes to preventative maintenance, it's best to use a kit and replace many other components that the timing belt interfaces with at the same time the timing belt is replaced, no doubt.

However, what we do not agree upon are the following statements such as:

"What I said was timing belts always outlast the other components that the timing belt interfaces with, and other component failure is ultimately the cause of the timing belt failure, no matter when the other components ultimately break, be it at 70K, 90K or 200K miles."

"Second, if real world experience shows that the other components always fail before a timing belt, no matter the miles, why would you change out only the timing belt at 90K miles and expect all of the other components to last until the 180K mile mark, which would be the next scheduled timing belt change? PURE STUPID."

Replace the word "always" with "can" and these statements make more sense. I've had a timing belt break on another vehicle in the past with no other component it interfaced with having any damage whatsoever. I know timing belts have improved and should outlast other components that they interface with, but it's not always the case, there are many other factors that could affect the life of a timing belt.

My last post on this topic that we agree to disagree upon.

 

The objective of using the word "always" is to make it automatic in each of the readers minds that all components that touch the timing belt should be changed, given the failure mode history and given the cost to benefit ratio.

I agree that normally "always" is a strong word, but in this case "always" is a much more appropriate word than the relatively wimpy word "can". Example: A Dodge "can" be more reliable than a Lexus, but it is so rare that the word is inappropriate in the context.

There might have been that 1 in 1000 case in Timbuktu where the belt broke on its own, but I have never heard of it, and no one I have ever met has. "Always" fits perfectly as a rule of thumb in this particular case.

I believe we are both passionate about transferring the best of our experience to other users on the forum so they can best maintain their SC430, and not be taken by either clueless or unscrupulous dealers.

And as long as we are rehashing the subject, a seized water pump is probably the most common of the components failures. What can you do? Change your coolant every two years to keep the water pump properly lubricated.

I reiterate: Timing belt components ALWAYS break before the belt - so change ALL associated components when the belt is changed.