gmanbox

I have an '09 LS 460 AWD and there is a very unlike Lexus knocking sound at idle to maybe up to 20mph. best way I can describe is to imagine a diesel engine at idle, and dilute it substantially. subtle but clearly there. i read here in CL that could be due to valves or such, but dealer insists it is because of the intentionally designed "oversized fuel pump and fuel injector" and completely normal. Anyone hear of such a thing? Anything specific I can tell them to check / fix in particular? I'm fine if this is truly normal but shocked Lexus would design this into its flagship sedan.

jmcraney

The "oversized fuel pump and fuel injector" noise explanation may be a dealership euphemism for a condition called piston slap.

Others have gotten the "fuel pump and injector noise" explanation regarding their concerns about unusual engine noises.

This link might be interesting: https://www.clublexus.com/forums/ls4...t-low-rpm.html

edarte

I suspect you are hearing what is thought to be a "tap" or "ping" from the high pressure direct injection. I have learned to live with it but I did not expect it in a car of this quality. Thought Lexus would have figured out a solution by now, if only more sound insulation. Some days it is noisier than others.

If you search this forum for "injection" you will find other posts on the subject

gmanbox

Thanks, yes. jmcraney had a link in his response I re-read, which had someone negotiate to have the pistons replaced at Lexus' expense that fixed this for them. I'm trying to obtain written communication from his lexus dealer that i can use with my dealer. but that sounds like serious surgery, and wondering if worth the effort, and more importantly, if the legendary reliability of the car will suffer as a result.

gmanbox

To update interested folks... So a lexus "specialist" in the area took it for a test drive on my 3rd drop off of the car. I was unable to be present at that time to speak with them directly while testing. The dealer called me a day later to say that the specialist thought it was 'within the normal range', which is hogwash, and said to call customer support for them to investigate.

So these people are supposed to investigate by speaking with various people who've seen my car and determine a course of action. Round 1 was a response that was an *exact* read of what the dealer told me (which was the reason I came to them in the first place). Not satisfied and with me explaining that 1) why did the dealer foreman/expert on my 2nd visit then agree making MORE noise than other similar cars, and 2) it seems it's gotten louder since a recall with engine valve replacements/adjustments, and what part of that is "normal", they're doing more work and as of now think i need to take the car in again.

One kind ClubLexus colleague generously gave me his VIN to support one idea of replacing pistons to fix piston slap, which was done to his vehicle. Any other suggestions?

Frankly, I'm not a lawyer, in fact hate reading about frivolous lawsuits, and have way to. many other things to worry about, but this is starting to have the ingredients of a good case where multiple owners have been neglected by Lexus. What they're trying to do is just wrong, and doesn't pass my 'family' test (how would i feel if they were doing this to a family member).

Suggestions welcome, otherwise will keep you posted for others to benefit.

rfam

I too have the same noise in my 2012 ls460-especially on cooler mornings. Been to 3 different Lexus dealerships-same explanation-high pressure fuel pumps, chain driven, etc. When you're coming out of a 2000 ls400, it sounds incredible that this is a Lexus engine! I've noticed some difference switching from 5w-20 synthetic to 0w-20 synthetic BUT the real test will come this fall/winter when the temps drop lower. Just can't believe Lexus would have their flagship sound like a muffled diesel.

Bob04

I have it on my 2010. Absolutely hate the car. Will be my last Lexus. Inexcusible. There are times it is louder than my turn signal blinker. Hate the car with a passion. I wish a sinkhole would open up under that POS while in the parkjng lot one day while I'm at work.

Bob04

I got the "it's normal" bull**** from the service associate before anybody at the dealership even listened to it. Really hacked me off. I know something else that's going to be normal. Me not purchasing a Lexus.