I have a question for my LS430 experts. I would much rather hear from you than a dealership who only wants to take your money. It's a small but I think important question. I purchased my 2004 LS430 in 2007 with 13,000 miles on it. Today I have 57,500 miles on it. When I first bought it and for years after when the engine was running I couldn't hear it. As the years went on I didn't pay much attention to the sound Possibly meaning the noise only increased slightly? Today the running engine is very noticeable. There is nothing wrong with engine it runs fine enough but how did this go from not hearing it at all to this ? Dash shows no warning. I change the oil when needed. I just changed the air filter and my mileage per gallon went up from 15mpg to 17mpg. Old one was seriously dirty , my error in keeping it too long. A couple of months ago I had to replace the serpentine belt. I have always used regular gas from when the engine was quiet to today. I was told that the car automatically adjusts to whatever grade of gas you use. Lexus dealers say you have to bring in the car at 50,000 for their 50,000 mile service, what ever that is. I did not do this. What can I do to quiet my engine? Thanks to all...

 

Are you talking about the fuel injectors which can be loud and make a ticking noise? (This is not a worry.) What does your dealer say it is? Has anyone else listened to the engine and made a diagnoses?

Start using premium gas. When Toyota says the engine requires premium, believe it. Computers may adjust the ignition system to accommodate lower-octane gasoline, but, the knock sensors and ability to retard the spark timing doesn’t mean premium is unnecessary. (See your mpg go up too because your 3UZ-FE engine is tuned to run on premium.)

 

This guy is knowledgeable. Look what he wrote:
Here is a guy who may be an ace wrench in a neighboring state and may be near you. Maybe ask if he may be willing to help you with your maintenance and what amount he would like to do so if he will:

 

Thanks guys for your input. The engine is not ticking or making any radical sounds of any kind. It is just the natural idle rev or roar of just being running is louder than when in the past I could hardly tell if the engine was on or not. Is it the age, the miles, or should I have something replaced or adjusted. If you really think it is the gas and I should now use the middle grade I'll do it. But the regular gas must some kind of accumulative effect over the years because it did earlier run quiet on regular gas. Any ideas.......

 

Use PREMIUM, 91 octane or higher, gasoline in your LS 430, irrespective of any sound you are hearing. When Lexus says the engine requires premium gasoline, believe it. The manufacturer does not say premium gas is recommended for the LS 430, It says USE PREMIUM GASOLINE ONLY which means PREMIUM (91 octane or higher) gas is REQUIRED, (If you have a Costco or Sam's Club, you can buy premium for 10% more than the cost of regular. And if your mpg go up even only 10%, premium pays for itself anyway.) DO NOT use regular or mid-grade. USE PREMIUM. 91 octane or higher. If you are in a pinch sometime, and regular or mid-grade is all that is available, well ok, for that incident. But, otherwise, ALWAYS USE PREMIUM gasoline.

Is the sound you are describing an exhaust leak?

Please watch this video which discusses the matter of proper fuel. (if you watch this video, look at the parts from a car's engine ... Do you think you should switch to PREMIUM ONLY now? (YES, YOU SHOULD!) ...

 

Octane rating aside these cars are known to have exhaust leaks at the Y pipe where the heat shields rub a hole. I would bet the increased sound from the engine is related to an exhaust leak.

 

As you know, octane may not effect an exhaust leak. But may you please post your new and higher mpg if/when you start running premium....

 

If you are going to use the Edit feature please use it correctly for minor punctuation or to add relevant info. Using it to delete or change the post entirely in the interest of covering your tracks benefits no one. Members need to see the advice you are offering is quickly copied from a barely credible YouTube video (original video posted before delete and edit- )

 

A complete fabrication and falsehood. One and only one video link was ever placed in post 5 of this thread....

 

Not really. I've got almost 40,000 miles and 120 tankfulls of either premium or regular gas tracked in Fuelly and there is no difference in mileage between the two for me. There are other threads on this forum that discuss this topic ad nauseum. For certain, running regular gas in your 430 isn't going to make it run any noisier...

 

Agree. It would not be octane of gasoline making it run noisier. The way OP describes the noise may incline one rather to examine the exhaust system....

 

I think you need to be a little more specific. When you say running, do you mean sitting in the car while it is idling? Or is it also when you are driving the car? What kind of specific noise are you hearing? Injector tick? Power steering whine? Have you ever had the car serviced anywhere? Do you have a trusted mechanic? You really are only going to get conjecture from any of us because we can't hear the car ourselves. If you could post a video that would be helpful but the only way you are going to get any real help on this I'm afraid is to take it in and get it looked at by a mechanic...

 

If I was going to take a guess with the limited information available I'd say have your mufflers checked out. The OP lives in New York where there is an abundance of road salt used. I know right now, my drivers side muffler has one or more holes in the top of the it and it is making my car noisier. Leaks in the Y-pipe area will typically end up throwing a check engine light which also happened to me last winter. The y-pipe leak was barely audible but the leak coming from the muffler is noticeable especially if you get out of the car and walk in the back...

 

If its not underneath the car and more noticeable at the front of the engine, its the exhaust manifold(s). Listen by the wheel well on both sides. My 06 was whisper quiet at 104k and now at 165k I can hear the engine from a few feet away. Its just what happens to old cars. Nothing to worry about unless you want to replace the manifolds which is big $$

 

I have always been able to hear my engine, but only very slightly when cruising. When accelerating I can hear it but it is very muted. I once read a review of these cars that described them as being like driving a nuclear-powered hot-air balloon and I think that describes the normal engine sound to a T.

As for gas, I recently ran a whole year on premium and then switched several months ago to regular. There was absolutely no change in noise and the MPG went down by about 1 mpg around town (haven't been on a long highway trip yet). I see others are adamant about using premium, but if you are using top tier gas then I doubt it makes a difference besides power and mpg (which is minimal).