Engine Noise

[LLarry]

I purchased a used 2008 LS 460L with 45K miles on it a few weeks ago, and noticed after I purchased it a valve noise on start up. The noise is subtle and will go away when the car is warm. I'm thinking a valve lifter not getting the oil at first. I had it in to the dealer for an oil change and they said nothing about it. I wanted them to say something first. I'm wondering if anyone else has noticed this. I also have a 97 LS 400 250 K miles and a 03 SC430 25K miles. None of the others have this noise. I kind of surprises me, I would have never expected it from a Lexus. The car is a dream to drive and I enjoy it very much. I have a good dealer, and have trust in him. I have an extended warranty on the car till 100K, so I have time to see if it gets any worse. What would you do?

[apna garage]

have them check for service bulletins and also have them document the concern for the fuutre

[DEATH]

I purchased a used 2008 LS 460L with 45K miles on it a few weeks ago, and noticed after I purchased it a valve noise on start up. The noise is subtle and will go away when the car is warm. I'm thinking a valve lifter not getting the oil at first. I had it in to the dealer for an oil change and they said nothing about it. I wanted them to say something first. I'm wondering if anyone else has noticed this. I also have a 97 LS 400 250 K miles and a 03 SC430 25K miles. None of the others have this noise. I kind of surprises me, I would have never expected it from a Lexus. The car is a dream to drive and I enjoy it very much. I have a good dealer, and have trust in him. I have an extended warranty on the car till 100K, so I have time to see if it gets any worse. What would you do?

No service bulletins for engine noise on cold start-up for this model. If you brought it in already warm, they wouldn't hear it any way. Mention it to them and arrange to leave the car the night before so someone can hear it when it is first started.

[Ed Darte]

What you are probably hearing is what most owners believe to be caused by the high pressure of the indirect injection. My 2009 LS had a mild "valve tappet" sound and my 2011 is slightly quieter. My 2001 LS was whisper quiet. Note, some very knowledgeable owners due claim the Indirect injection is not the cause but I am not aware of anyone having this noise ever having it eliminated.

The one other, slim, possibility is the infamous valve spring failure problem. Lexus has issued a recall on this problem where there is a slim possibility of a spring failure that could cause engine failure.

See this site http://www.lexus.com/recall/#hs3RecallSection

[JimBBB]

I have a 2013 LS 460L with what appears to be the same noise. I've hear descriptions of the noise I am referring to as being very similar to this. One person I know also indicated the sound I had sounded like a fan belt as someone else on this topic mentioned.

The dealer I use also reports this noise is normal but explains what the noise is from. The dealer claims it is a noise caused by Direct Fuel Injection. The other person on this topic called it I believe Indirect Fuel Injection. It was explained to me that Direct Fuel Injection on the newer cars these day is different from the fuel injection engines of older days. The older cars had fuel injected into the cylinder on the out stroke of the piston. In Direct Fuel Injection engines, the fuel injection occurs on the in stroke of the piston (when compressing the gas in the cylinder). It is this injection during the compression phase that causes this clicking/tapping sound. In my car, I seem to notice the clicking/tapping all the time when the car is at idle because there is less engine noise at the lower RPM but I believe though I do not actually hear the noise that it must always be present but not audible over the engine noise of higher RPM.

[Jeff in TX]

Ask your dealer to show you three other cars on his lot that have this "Direct Fuel Injection Noise." To remove sujectivity from your discussion with the dealer, use a sound meter to quantify the peak noise from your car and the other three for comparison.

[Jayson4it2]

Good luck with the three car comparison... you may get one car :)

I do agree with Jim about the Direct Injection... its kinda like a diesel injection system. They work under very high fuel pressure and they are louder then standard fuel injectors.

But i'm not sure if that is what you are hearing.

[1Putt]

The most common explanation will be the direct injection system that the ls460 and newer cars have versus the ls430. My understanding is the sound is caused by the 2 high pressure fuel pumps operating. There is also some type of solenoid(s) in play also, but I don't know the specific details. So this noise is normal.

The worst case scenario which I've read about on another forum is one owner who had the fuel pumps replaced under warranty, and the noises persisted. After some haggling, Lexus replaced all the pistons in his car and the noise stopped and has not resurfaced so far. This may have been piston slap, which is typically loudest when engine is cold right after start up. I believe piston slap does not necessitate corrective action

[Poodleman]

I found this discussion enlightening and especially in view of comparison on the engine sound of the LS460 with the LS430. I had a 2005 LS430 with less than 42,000 miles which I purchased a year ago (March 2014). It was the quietest car I have ever owned (and I have owned quite a few Cadillacs over the years). When at idle, I had passengers comment on the quiet....and ask if the engine was still running! The car was stolen in March 2015 and severely wrecked. I was very sad to lose this car. I have replaced it with a 2009 LS460. During the test drive, I did not notice the sound described above, but since then, I have spent some hours in the car (purchased in March, 2015), I have noticed the sound you all have described upon start up and during idling. At first, I was concerned something was wrong with the engine, but the dealer told me that all was well with the car during my last 60,000 mile service. I have come to accept the fact that the LS460 engine is really just different than the LS430 engine. I am very pleased with the performance and handling of this car, which feels like it has more presence and substance (and weight) than the LS430. However, after reading so many comments about engine sounds, I have come to accept that the LS460 engine is more audible under acceleration and idling than my previous LS430. However, once underway, it is serenely quiet and a dream to drive. I personally prefer the LS460 overall.

[jainla]

The UR V8s are definitely noisier than the older UZ units. There are a couple reasons for this:

Timing Chain: the UR engines (LS 460/600) use a timing chain rather than a timing belt (LS430). The timing chain lasts longer than the belt but is noisier. The UR engines sound more like a Mercedes V8 when revved hard; whereas the UZ engines still sound like tearing silk.

Dual Fuel System: the UR engines have both direct and indirect fuel injection; the engine activates them as needed and at different RPM/use case scenarios for best efficiency and drivability. The DI fuel injection system (which is always on) needs to operate at extremely high pressure because it often injects fuel directly into the cylinder during the compression stroke; and the pump and injectors are louder (much like a diesel). I'm sure having 2 systems means more parts to warm up and make noise. Every recent car with DI has echoes of an old diesel when I stand next to it.

VVTI-E: the dual VVTI system forces the use of 2 camshaft gears; whereas the older UZ engine have a single drive gear off the belt that drives the intake cams which then drive the exhaust cams via scissor gears; which are very quiet. I'm not sure if the VVTI system in the later UZ engine has a single cam gear drive off the belt or 2.

Also Lexus seems to have just dialed in more engine and exhaust noise in the latest version of the LS. I can clearly hear some exhaust rumble when I toe into the power on the 600h; whereas my 430 you just hear a faint hum. At 114k miles the 430 is still silent at idle; actually quieter than the 600h when the gas engine is on. You can't really hear the 430 engine until you wind it past 3000 RPM; whereas the 600 you always know when it's on if the radio is off and climate control isn't working too hard. It's not loud or really that noticeable where it not for the eerie silence of the 430 engine in the same conditions; also in the hybrid the engine cuts on and off continuously at lower speeds; were it on all the time I might not notice as much.

Also in either car once you're going past about 30 mph the minimal road noise easily drowns out whatever engine noise you would hear.

The UZ engine is still amazing. Toyota spent $400 million 1980s dollars to develop it and it seems it's worth every penny.