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Posted

I bought a 2000 LS400 2 years ago for $22K with a 39,000 mileage. The guy is the 2nd owner & sez he barely used the car becoz he has other cars to use. I just now reached the 90K mileage & according to Lexus dealer & other places I went, it is now due for a new timing belt also....the cost is between $480- $700 My other mechanic says that I should still be able to use it without any problem. One other mechanic says that he is surprised to have it replaced so soon as other don't do it until 120K miles....what do you think guys? Please advise & let me know who I should believe. I can certainly use the money for something else instead of the replacing the timing belt but then again I don't want to die should that thing failed on me. I do a lot of driving back & forth from San Francisco to Sacramento....about 200 miles roundtrip. The rest of the maintenance has been done except for the timing belt.

Posted

Pinkee, I said Do it and change the timing belt, just to have a piece of mind since you commute to the bay area often, the worst scenero is to have it go on you on 80 west. If it does break your motor is gone, i know its sucks but part of owning a luxury car. Just for the age i would change because rubbers do cracks, just my 2 cents. I have a 99Ls, change my serpentine belts becaue it had some cracks possible from heat, it can probably go for another 15-20k mile, but like you i commute often, and knowing that it can breaks and leave my stranded is not worth that headache and worry, i plan to do my timming belt when it hit 90k, no question ask. DO it MEN

An

Posted

Yeah I would go ahead and do it, its an interferance engine. It probably would las longer, but better safe than sorry.

Posted
Pinkee, I said Do it and change the timing belt, just to have a piece of mind since you commute to the bay area often, the worst scenero is to have it go on you on 80 west. If it does break your motor is gone, i know its sucks but part of owning a luxury car. Just for the age i would change because rubbers do cracks, just my 2 cents. I have a 99Ls, change my serpentine belts becaue it had some cracks possible from heat, it can probably go for another 15-20k mile, but like you i commute often, and knowing that it can breaks and leave my stranded is not worth that headache and worry, i plan to do my timming belt when it hit 90k, no question ask. DO it MEN

An

Posted

Thanks guys for the quick response. Don't know much about car, just driving it. BTW, with the cost of the gas, are you guys still using the premiun or the regular or mid grade? What happens if you choose to have the lower grade? Will that ruin the car? Would you have any tell tale signs or weird sounds that would indicate that it has adversely affected your car by using the lower grade gasoline?

Posted

hi Pinkee, i use premium on mine, there is a huge debate on this topic, just do a search and you can read all about and decide what you do. I personally did a couple of trial on mine on regular notice a decrease in MPG about 2 gallions and a little different on acceleration. In the long run i don't know. but I use premium on mine, it is after all a world class engine if not these most efficient and duralble v8 engine ever produce. One of the top dog of all engine, after my trial i wouldn't use anything less than 91 octane.

An

Posted

The timing belt will look real good like it can go another 90k so your changing it for nothing. This will *BLEEP* off many in this forum but it is the truth. Timing belts are made so big and strong I'm surprised they even still advise changing them at less than 150k. More likely is a water pump, idler or tensioner bearing going bad. If you insist on going in there change them all along with the plugs, caps & rotors, wires & serp belt. Or just wait till 120k plus and do it all. A mechanic friend of mine and I just had this discussion. He said he hasn't changed a worn out belt with under 150k since the mid 90's.

Posted

It sounds to me like some folks have never seen or repaired an engine that has stripped a timing belt or snapped one. It ain't pretty. Of course I've made some money over the years from those damaged engines.

In BMW sixes, the $400 belt job, if ignored, runs $2k for the head gasket and at least six valves, and then of course the new belt anyhow....

In Honda 12 valvers ( a Canadian only engine I think) 8 of the valves get bent. New head gasket. And a new belt anyhow.

On Volvo 20-valve five cylinder engines it's much simpler. The engine is destroyed. All valves bend, the valve guides crack, and the pistons are damaged too.

So go ahead - drive it until it snaps. Let us know the cost. I for one am extremely interested to know just how expensive the repair on a Vvti Lexus V-8 is. I know what the belt costs.

Posted
It sounds to me like some folks have never seen or repaired an engine that has stripped a timing belt or snapped one. It ain't pretty. Of course I've made some money over the years from those damaged engines.

In BMW sixes, the $400 belt job, if ignored, runs $2k for the head gasket and at least six valves, and then of course the new belt anyhow....

In Honda 12 valvers ( a Canadian only engine I think) 8 of the valves get bent. New head gasket. And a new belt anyhow.

On Volvo 20-valve five cylinder engines it's much simpler. The engine is destroyed. All valves bend, the valve guides crack, and the pistons are damaged too.

So go ahead - drive it until it snaps. Let us know the cost. I for one am extremely interested to know just how expensive the repair on a Vvti Lexus V-8 is. I know what the belt costs.

Amen! Mine had a split 3/4 of the way across one section and a lot of them 1/2 way across. The quote of $400 is really low, if it is a good mechanic and japanese parts I'd jump at it! Make sure he/she does the water pump too! ;)

Posted
The timing belt will look real good like it can go another 90k so your changing it for nothing. This will *BLEEP* off many in this forum but it is the truth. Timing belts are made so big and strong I'm surprised they even still advise changing them at less than 150k. More likely is a water pump, idler or tensioner bearing going bad. If you insist on going in there change them all along with the plugs, caps & rotors, wires & serp belt. Or just wait till 120k plus and do it all. A mechanic friend of mine and I just had this discussion. He said he hasn't changed a worn out belt with under 150k since the mid 90's.

You're absolutely right, and it probably will look totally fine.

However, the repair deriving from a snapped timing belt is probably going to be $6.....7,000. Why take a chance? Lexus says change it at 90k, they've got to suggest doing that for a reason. They don't make profit off of dealer service either, dealers are independently owned.

Thanks guys for the quick response. Don't know much about car, just driving it. BTW, with the cost of the gas, are you guys still using the premiun or the regular or mid grade? What happens if you choose to have the lower grade? Will that ruin the car? Would you have any tell tale signs or weird sounds that would indicate that it has adversely affected your car by using the lower grade gasoline?

This is another area where you're potentially shooting yourself in the foot by being cheap. The vehicle is designed to run on premium. Will it run on regular? Yes. Will it do damage? Potentially. Regular gas doesn't burn as fast which can cause carbon buildup that rubs power and economy.

So, while regular may save you a few bucks in the short term (its really not much), its going to cost you in the long term due to poor economy.

Lets do the math. The LS has a 22 gallon tank if Premium is $4 a gallon it costs $88 to fill the tank. At 19 MPG thats a range of 418 miles, or $.21 a mile. If you are using regular and saving $.30 a gallon and its $3.70, its $81.40 a difference of $6.60. If your mileage stays the same thats $.20 a mile. So it saves you 1 cent per mile. If you loose 1MPG while using regular, thats $0.21 a mile, no savings. 2MPG? $.22 a mile, costs you an extra penny.

Remember, even if the ECU adjusts to the regular fuel and you don't loose any economy at first, you're saving a penny a mile. But the effect of carbon buildup is cumulative. Ultimately, in the best scenario its not going to save you anything, it may even cost you more.

The bottom line is these are not cheap cars to own really. You have a very nice low mileage LS, a car that rides and drives better than almost every brand new car on the road. They require maintenance, and they require premium fuel. If you want something thats not going to need these things...you should probably look at something smaller and more economical, like an Accord or Camry.

The LS is a great car, and if you treat it right it can be humming like a top at 200,000...300,000 miles. BUT, you've got to treat it right, use the right fluids and fuel, do maintenances when they need to be done like the timing belt replacement and stay on top of repairs.

If you DON'T do those things, then these can be VERY expensive cars to own.

  • 2 weeks later...
Posted

I concur with the majority that replacing the timing belt is good preventive maintenance. Sure, the belt may make it to 150,000 miles or more.............but what if it doesn't? You don't get a warning light before the belt goes and significant engine damage occurs.

On the issue with the grade of gasoline used, I would be much more concerned about pre-detonation (pinging) than trying to compare fuel economy on different grades. Premium fuel is required by engines that run at higher compressions to avoid pre-detonation. Pinging over time will damage your engine internals.

I have never experimented using lower grade fuel in my Lexus......so maybe you can get away with it without pinging. My thought is with such a small difference in price, why risk it? Lexus does not have anything to gain based on what grade of gas that you use, so why not follow their recommendation?

Posted
The timing belt will look real good like it can go another 90k so your changing it for nothing. This will *BLEEP* off many in this forum but it is the truth. Timing belts are made so big and strong I'm surprised they even still advise changing them at less than 150k. More likely is a water pump, idler or tensioner bearing going bad. If you insist on going in there change them all along with the plugs, caps & rotors, wires & serp belt. Or just wait till 120k plus and do it all. A mechanic friend of mine and I just had this discussion. He said he hasn't changed a worn out belt with under 150k since the mid 90's.

You're absolutely right, and it probably will look totally fine.

However, the repair deriving from a snapped timing belt is probably going to be $6.....7,000. Why take a chance? Lexus says change it at 90k, they've got to suggest doing that for a reason. They don't make profit off of dealer service either, dealers are independently owned.

Thanks guys for the quick response. Don't know much about car, just driving it. BTW, with the cost of the gas, are you guys still using the premiun or the regular or mid grade? What happens if you choose to have the lower grade? Will that ruin the car? Would you have any tell tale signs or weird sounds that would indicate that it has adversely affected your car by using the lower grade gasoline?

This is another area where you're potentially shooting yourself in the foot by being cheap. The vehicle is designed to run on premium. Will it run on regular? Yes. Will it do damage? Potentially. Regular gas doesn't burn as fast which can cause carbon buildup that rubs power and economy.

So, while regular may save you a few bucks in the short term (its really not much), its going to cost you in the long term due to poor economy.

Lets do the math. The LS has a 22 gallon tank if Premium is $4 a gallon it costs $88 to fill the tank. At 19 MPG thats a range of 418 miles, or $.21 a mile. If you are using regular and saving $.30 a gallon and its $3.70, its $81.40 a difference of $6.60. If your mileage stays the same thats $.20 a mile. So it saves you 1 cent per mile. If you loose 1MPG while using regular, thats $0.21 a mile, no savings. 2MPG? $.22 a mile, costs you an extra penny.

Remember, even if the ECU adjusts to the regular fuel and you don't loose any economy at first, you're saving a penny a mile. But the effect of carbon buildup is cumulative. Ultimately, in the best scenario its not going to save you anything, it may even cost you more.

The bottom line is these are not cheap cars to own really. You have a very nice low mileage LS, a car that rides and drives better than almost every brand new car on the road. They require maintenance, and they require premium fuel. If you want something thats not going to need these things...you should probably look at something smaller and more economical, like an Accord or Camry.

The LS is a great car, and if you treat it right it can be humming like a top at 200,000...300,000 miles. BUT, you've got to treat it right, use the right fluids and fuel, do maintenances when they need to be done like the timing belt replacement and stay on top of repairs.

If you DON'T do those things, then these can be VERY expensive cars to own.

I agree with this completely. just follow the maintainence, use OEM parts if possible, and actually this car is super cheap compared to almost anything remotely close to this class. I've spent about... less than $500 on maintainence(DIY) and repairs over the past 2+ years and 50k miles. My car is almost at 260k and is still butter smooth. Once i get my escort pony (clean old beater) runnin good, I'm gonna prolly spend about $700 on suspension parts, and more maintainence i've neglected. my LS deserves it. Its too good a car. she still gets prem too. :) I'm amazed that i'm still infatuated with my car.

Posted

Since it is an interference engine, I would change it for peace of mind. My 00' Toyota Tundra V8 was also an interference engine. It had 106K when I sold it on the original belt. Recommended change was 90K. I was paranoid. I did not want to spend to much $ on it since I was going to sell. I warned the buyer it was past due for this belt, hence the great deal he got on it. A like new Toyota Tundra V8 SR5 4wd for $10,500. I was a fool to sell it that cheap... even nice 98-00 Tacomas are selling for $8-9K even with their frame rust recall issues. :rolleyes:

The timing belt on my last 1991 LS400 lasted until 180K! It was a non-interference engine though.

My current LS has 214K and the timing belt and water pump were last changed at 178K, so I have awhile yet to go.

Good luck!

Posted

Here's what it looks like when the valves and pistons miss a step while waltzing down the road. Your TB is all that keeps this from happening. Your common sense determines how goes the dance.

Piston1.jpg

Posted
I concur with the majority that replacing the timing belt is good preventive maintenance. Sure, the belt may make it to 150,000 miles or more.............but what if it doesn't? You don't get a warning light before the belt goes and significant engine damage occurs.

On the issue with the grade of gasoline used, I would be much more concerned about pre-detonation (pinging) than trying to compare fuel economy on different grades. Premium fuel is required by engines that run at higher compressions to avoid pre-detonation. Pinging over time will damage your engine internals.

I have never experimented using lower grade fuel in my Lexus......so maybe you can get away with it without pinging. My thought is with such a small difference in price, why risk it? Lexus does not have anything to gain based on what grade of gas that you use, so why not follow their recommendation?

What they have to gain by recommending premium is a higher fuel economy rating. These engines/cars were introduced during the OTHER recession, 1990-93. The 4.0 is fuel hungry enough, let alone having sales affected by publishing the fuel economy of it running on a recommendation of 87 octane. Yes it is a luxury car, I know, I know.... :rolleyes: Have you ever seen how cheap the old people are in the wealthy communities in Florida and Arizona? My family has a winter house in Boca Raton. They DO care for sure.

Posted
What they have to gain by recommending premium is a higher fuel economy rating. These engines/cars were introduced during the OTHER recession, 1990-93. The 4.0 is fuel hungry enough, let alone having sales affected by publishing the fuel economy of it running on a recommendation of 87 octane. Yes it is a luxury car, I know, I know.... :rolleyes: Have you ever seen how cheap the old people are in the wealthy communities in Florida and Arizona? My family has a winter house in Boca Raton. They DO care for sure.

I think your logic is reversed on octane and fuel economy. A high performance engine that runs at higher than typical compression requires the use of higher octane fuel to avoid predetonation (i.e., pinging). It has absolutely nothing to do with fuel economy. That being said, if pinging IS detected, the car's emissions system will trigger an adjustment in timing in an attempt to avoid the pinging, but in so doing, the engine will be less efficient.

If your car is designed to run on "regular", there is no benefit to using "mid-grade" or "premium". If your car is designed to run on "premium" and a lesser grade is used, the risk is pinging, or at a minimum, lower efficiency and therefore fuel economy as it adjusts its timing to avoid the pinging.

Given that prolonged predetonation can cause serious damage to an engine, why risk it?

Posted
What they have to gain by recommending premium is a higher fuel economy rating. These engines/cars were introduced during the OTHER recession, 1990-93. The 4.0 is fuel hungry enough, let alone having sales affected by publishing the fuel economy of it running on a recommendation of 87 octane. Yes it is a luxury car, I know, I know.... :rolleyes: Have you ever seen how cheap the old people are in the wealthy communities in Florida and Arizona? My family has a winter house in Boca Raton. They DO care for sure.

I think your logic is reversed on octane and fuel economy. A high performance engine that runs at higher than typical compression requires the use of higher octane fuel to avoid predetonation (i.e., pinging). It has absolutely nothing to do with fuel economy. That being said, if pinging IS detected, the car's emissions system will trigger an adjustment in timing in an attempt to avoid the pinging, but in so doing, the engine will be less efficient.

If your car is designed to run on "regular", there is no benefit to using "mid-grade" or "premium". If your car is designed to run on "premium" and a lesser grade is used, the risk is pinging, or at a minimum, lower efficiency and therefore fuel economy as it adjusts its timing to avoid the pinging.

Given that prolonged predetonation can cause serious damage to an engine, why risk it?

I drive exactly the same kind of cars as you! LS400, a hi reving special sport edition miata and an izuzu 220 hp suv! We girls think alike! Oops I mean you think like me! The car gets lower gas mileage with regular. I'm sure the computer will let it run on 104 octane too and get better gas mileage since it is a higher energy fuel, so what is your argument again? You did say the computer adjusts to prevent predetonation right? So where is the damage? I can understand if you are used to twisting the distributor too much on your old mustang, but nah it just is not the same on these cars... don't buy it yet.

BTW do you know the compression ratio of the UFZ 4.0 Liter in the 400's at each model year? Here is where we can break down how high performance this engine really is. Remember it VARIES for certain years and the discussion loses a lot of traction if you are talking about certain years. Traction... ooooo....car pun, sorry. :D


Posted
I drive exactly the same kind of cars as you! LS400, a hi reving special sport edition miata and an izuzu 220 hp suv! We girls think alike! Oops I mean you think like me! The car gets lower gas mileage with regular. I'm sure the computer will let it run on 104 octane too and get better gas mileage since it is a higher energy fuel, so what is your argument again? You did say the computer adjusts to prevent predetonation right? So where is the damage? I can understand if you are used to twisting the distributor too much on your old mustang, but nah it just is not the same on these cars... don't buy it yet.

BTW do you know the compression ratio of the UFZ 4.0 Liter in the 400's at each model year? Here is where we can break down how high performance this engine really is. Remember it VARIES for certain years and the discussion loses a lot of traction if you are talking about certain years. Traction... ooooo....car pun, sorry. :D

"The octane rating of a spark ignition engine fuel is the detonation resistance (anti-knock rating) compared to a mixture of iso-octane (2,2,4-trimethylpentane, an isomer of octane) and n-heptane. By definition, iso-octane is assigned an octane rating of 100 and heptane is assigned an octane rating of zero. An 87-octane gasoline, for example, possesses the same anti-knock rating of a mixture of 87% (by volume) iso-octane and 13% (by volume) n-heptane. This does not mean, however, that the gasoline actually contains these hydrocarbons in these proportions. It simply means that it has the same detonation resistance as the described mixture.

Octane rating does not relate to the energy content of the fuel (see heating value). It is only a measure of the fuel's tendency to burn rather than explode."

Octane has nothing to do with energy. The reason you get less fuel economy with a lower than called for octane is that your computer has to slow down your timing to avoid predetonation, causing it to operate less efficiently. In most cases with modern cars, they can run fine on regular grade fuel, albeit with less fuel economy and a decrease in horsepower at WOT. If you decide to do this, you should watch specifically for pinging, since if you experience prolonged predetonation, you will damage your engine. My owners manual states with regard to fuel that 91 should be used for optimum engine performance. It further states that if premium is not available, that 87 may be used temporarily.

Using your argument on octane and energy, an engine designed to run on "regular" would have improved fuel efficiency when running "premium". I have never seen anything to support this theory.

Posted
I drive exactly the same kind of cars as you! LS400, a hi reving special sport edition miata and an izuzu 220 hp suv! We girls think alike! Oops I mean you think like me! The car gets lower gas mileage with regular. I'm sure the computer will let it run on 104 octane too and get better gas mileage since it is a higher energy fuel, so what is your argument again? You did say the computer adjusts to prevent predetonation right? So where is the damage? I can understand if you are used to twisting the distributor too much on your old mustang, but nah it just is not the same on these cars... don't buy it yet.

BTW do you know the compression ratio of the UFZ 4.0 Liter in the 400's at each model year? Here is where we can break down how high performance this engine really is. Remember it VARIES for certain years and the discussion loses a lot of traction if you are talking about certain years. Traction... ooooo....car pun, sorry. :D

"The octane rating of a spark ignition engine fuel is the detonation resistance (anti-knock rating) compared to a mixture of iso-octane (2,2,4-trimethylpentane, an isomer of octane) and n-heptane. By definition, iso-octane is assigned an octane rating of 100 and heptane is assigned an octane rating of zero. An 87-octane gasoline, for example, possesses the same anti-knock rating of a mixture of 87% (by volume) iso-octane and 13% (by volume) n-heptane. This does not mean, however, that the gasoline actually contains these hydrocarbons in these proportions. It simply means that it has the same detonation resistance as the described mixture.

Octane rating does not relate to the energy content of the fuel (see heating value). It is only a measure of the fuel's tendency to burn rather than explode."

Octane has nothing to do with energy. The reason you get less fuel economy with a lower than called for octane is that your computer has to slow down your timing to avoid predetonation, causing it to operate less efficiently. In most cases with modern cars, they can run fine on regular grade fuel, albeit with less fuel economy and a decrease in horsepower at WOT. If you decide to do this, you should watch specifically for pinging, since if you experience prolonged predetonation, you will damage your engine. My owners manual states with regard to fuel that 91 should be used for optimum engine performance. It further states that if premium is not available, that 87 may be used temporarily.

Using your argument on octane and energy, an engine designed to run on "regular" would have improved fuel efficiency when running "premium". I have never seen anything to support this theory.

Uh huh. ...still waiting for the compression ratios; as they changed for each year of the 400's, so we can seperate apples from oranges... ...btw you might want to go on the new generation mustang forum and see if those boys notice a mileage or power increase from running premium. Tell them about your Honda S2000 too.... ....it will let them know you are a real car guru. Keep me posted!

Posted
Uh huh. ...still waiting for the compression ratios; as they changed for each year of the 400's, so we can seperate apples from oranges... ...btw you might want to go on the new generation mustang forum and see if those boys notice a mileage or power increase from running premium. Tell them about your Honda S2000 too.... ....it will let them know you are a real car guru. Keep me posted!

I am confused as to what point you are attempting to make regarding compression ratios. I have never tried to make any debate about compression ratios on various year models of the 400. The only point I made about compression ratios is that premium fuel is either required or recommended (depending on car and manufacturer) for engines that run higher than normal compression ratios. Are you attempting to debate this fact? Or if not, what point are you attempting to make, and to what statement of mine is it in relation to?

You stated that octane relates to energy. I merely pointed out that in fact, it does not. It is not "lower energy" of regular fuel that causes decreased fuel efficiency. It is due to the fact that the computer adjusts the timing to avoid predetonation, which causes the engine to run at a lower efficiency and lower power. I also stated that I have never seen any evidence that running a higher octane than required for a particular engine results in any increase fuel economy. Of course, this would refer to a stock engine. A modified engine (especially supercharged) that has different characteristics than stock, may well benefit from a higher octane fuel. I am not suggesting that I am the world expert on the topic; if you have any analyses that demonstrate that an engine designed to use regular fuel experiences increased fuel economy by the use of premium fuel, I am very interested in seeing it. In your response/sarcasm/challenge/whatever that was supposed to be, you ignored this topic entirely, and this is the only point I have attempted to make. Likewise, if you have any information that says that octane relates to energy, I would be interested in seeing that as well.

Posted

IS400, your tone is unneccisary. Mike has shown you plenty of respect and has shown a willingness to discuss your viewpoint vs his, show him the same courtesy.

  • 1 year later...
Posted

I use only Premium, top-tier fuels. Saving 5 or 10 cents a gallon means nothing to me. If I'd wanted a car that burned regular, I would have bought one.

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