hfahmy

Folks, I have 08 LS460 LWB with 48k miles with sport package and 07 LS460 SWB with 38k miles, the 08 is way louder than the 07 when cold. I can clearly tell the difference if I drive the two cars back to back specially when accelerating from cold start. When warm there is no difference. Anyone knows if the exhaust system in 08 is different? Is it different in the sport? If I have exhaust leak, does it manifest itself only when cold??? Appreciate any insights!!!

It is the wife car and she does not like the loudness in the morning...

Devh

Are they both AWD?
Is the sound louder when cold or does it settle down to be equal with the other car when it warms up?
Does the car sound louder outside then the other?

hfahmy

Both r RWD. I can mainly tell the difference when accelerating from cold. Once the 08 gets to normal operating temp there is no difference. The 08 sounds like an accelerating sports car from the inside when cold. When both are parked next to each other, there is no difference in sound from the outside, this applies hot or cold.

Devh

It's hard to quantify without being there. What I would do is start both cars cold with the engine hood up and take note of the engine sound level of both cars.
Keep in mind that no two cars will age the same and one will probably be a little louder over the life of the car.
If both cars are equal under the hood then I would take the car to a reputable shop and have them place the car under the lift to see if the exhaust manifold, catalytic converter and muffler joints is the source of the noise. Sometimes cars with leaks will be louder when the car is cold and as it warms up the metal expands and it seals up.

Some of the sound deadening material also gets degraded as time goes on and the car will have more engine sound in the cabin.

jgbackes

iTrader: (2)

Perhaps one of them has a cold air intake?

hfahmy

I am sorry! What do u mean by cold intake? Also, how to remedy?

korlexus

Something doesn't look stock near the engine.

jgbackes

iTrader: (2)

Are your cars "bone stock?"

hfahmy

Both cars are bone stock. I have done everything possible that can improve the 08 engine loudness, including changing spark plugs at 48K miles, cleaning TB, using injector cleaner, changing engine oil to Mobil1, etc. but still 08 is way louder at acceleration from cold start!

rfam

hfahmy, my 2012 ls460 has the same cold engine noise--loud knocking until it reaches operating temp. My next visit to a dealer will be next month where I will leave it overnight and return the next morning to test drive the car with the technician. I don't believe the understand the noise I'm referring to by my last few visits. Please let me know if you get any answers on your end.

anniversar

My 2010 LS460L AWD is also very noise when it is very cold. I never had this issue with my LS430. It seems to be a combination of a high level of intake noise and diesel like engine noise. The intake noise almost seems as if there is a hole in the bulk head which is letting noise through which of course there can't be as the noise reduces significantly when the car is up to operating temperature.

I understand that these cars to have some sort of active piped intake noise to enhance the sound of the engine and wonder if the way this works results in more noise being ducted into the passenger compartment when it is cold?

hfahmy

I took the car to a muffler shop and was told nothing wrong with the muffler pipe nor the CC. Also, said that they do not hear anything under the hood because car was already warn, asked to leave overnight. They told me if there is any leak it will be near the engine, it goes away after warm because of metal expanding closing any gaps.

PeteinPA

iTrader: (2)

I have an '08 and the engine is definitely louder at cold start. I wouldn't describe it as a loud knocking, just a loud compression like noise until it reaches operating temp. Please keep us posted.

thomastan

Is it a knocking noise? If so, it's call a piston slap. It's a major problem that Lexus headquarters are trying to keep it a hush hush issue and telling you that it's your fuel pump that is causing that noise. My wife's 2011 is at the dealer now and the head engineer ( Rusty Brown ) is flying in today to look at it. Another member had the same problem, Rusty approve his repairs and the car is normal now.

rfam

thomastan, do you know what repairs they performed?