2008 LS 460 Engine Knock
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Driver School Candidate
Joined: Sep 2014
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From: Iowa
2008 LS 460 Engine Knock
I have a 2008 LS460 with 115K miles on it. Noticed a knocking sound coming from front drivers side of the engine. The knock shows up when the engine is started cold and the fast idle drops out. After 3-5 min the sound drops way down, when it is making the noise it sounds like an air conditioner compressor cycling. It is not the air.
Took it to the dealer and had the engine tech listen to the noise..he said he had not seen this problem before and was not sure what it might be. Something internal could cost 800.00 to 5,000.00. I just drove the car on a 1,400 mile trip no issues other than the loud rattle when engine is first started cold. Not sure what to do next. Is this something the factory would help out with if its major?
I get no engine check lights or performance issues.
Took it to the dealer and had the engine tech listen to the noise..he said he had not seen this problem before and was not sure what it might be. Something internal could cost 800.00 to 5,000.00. I just drove the car on a 1,400 mile trip no issues other than the loud rattle when engine is first started cold. Not sure what to do next. Is this something the factory would help out with if its major?
I get no engine check lights or performance issues.
Pole Position
Joined: Oct 2014
Posts: 2,561
Likes: 365
From: New Hampshire
So is it a knock or a rattle? Either way it shouldn't be lasting for 3-5 minutes. I've heard a slight rattle out of my engine on a couple occasions, but it only lasts for a few seconds (if that). And usually it's after I drain the oil and fill. I have heard it before though, I attribute it to the oil needing a second to get up to the valve train or perhaps a little piston slap before the oil has a chance to coat them.
Thread Starter
Driver School Candidate
Joined: Sep 2014
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From: Iowa
Oil level good. Lexus tech did not feel it was caused by lifter getting oil. It is a metallic knock that cycles like the clutch of an Air Conditioner compressor. One thing I have been told is it could be the cam phaser ( that's the 5,000.00) fix. If that's the case I think I need to appeal to the factory.
You can hear the faint sound after the 3-5 min time frame
You can hear the faint sound after the 3-5 min time frame
Driver School Candidate
Joined: Feb 2006
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From: nj
I have the exact same sound from my car which is a 09' AWD with 135k miles at cold start. It is very noticeable and can be heard from 20ft away from the car. I just checked my oil today and have lost well over 2 qts of oil in the last 5k miles and now the oil doesn't even show on the dip stick.
I'm going to fill the oil back up to the high mark and report back if this resolved my issue.
I'm going to fill the oil back up to the high mark and report back if this resolved my issue.
Thread Starter
Driver School Candidate
Joined: Sep 2014
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From: Iowa
Thanks for the reply. Guess I am going back to the dealer today and visit with them. Going to leave the car over night so they can hear the sound from a cold start. My oil level has been and is fine.
I am also going to get an exact price on a cam phaser replacement
I am also going to get an exact price on a cam phaser replacement
Pole Position
Joined: Aug 2015
Posts: 299
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From: NJ
Don't forget, up to 90% of engine wear happens at these cold starts. Hearing any kind of flow related noise is sign. Sometimes timing belt and chain tensioners can be the culprit. I would do an engine flush and run better synthetic oil. Carbon building slowing oil flow is also an issue. This is why I would flush the system. Another way would be to replace a quart of oil with Marvel Mystery. This worked well on my LS430 that developed little vale noise on cold starts. Ran it for about 3k miles and changed the oil and cleared it up right away.
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Intermediate
Joined: Oct 2016
Posts: 346
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From: SC
I've heard the EXACT same noise on mine. I'm 12,000 miles into ownership (currently 94k) and it's very intermittent. I've had a used oil analysis done and it came back clean. I wouldn't worry about it but please let us know if you find out what the culprit is.
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Thread Starter
Driver School Candidate
Joined: Sep 2014
Posts: 15
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From: Iowa
Had a nice visit with the service manager at my local Lexus dealer yesterday. I asked if I was to leave the car overnight so the tech could hear the knock from a cold start. We concluded I could but it would not gain much in the diagnostic process. So I asked the approx. cost to replace the cam phaser any sensor/solenoid. He looked up the labor hours which came in at 2,000 to 3,000 with out parts. The parts guess would add another 1,000. I told him it was not a good idea to spend that much on a car with a value of 13k. He suggested I add an engine oil additive and see what happens, which I have done. I took a 2 hour drive to allow it mix. This morning started it cold the knock was quite a bit less but still there, after the engine kicks off of fast idle and then goes away.
I will see what happens. Either (hope) it improves or get a different car.
I will see what happens. Either (hope) it improves or get a different car.
Intermediate
Joined: Oct 2016
Posts: 346
Likes: 31
From: SC
Had a nice visit with the service manager at my local Lexus dealer yesterday. I asked if I was to leave the car overnight so the tech could hear the knock from a cold start. We concluded I could but it would not gain much in the diagnostic process. So I asked the approx. cost to replace the cam phaser any sensor/solenoid. He looked up the labor hours which came in at 2,000 to 3,000 with out parts. The parts guess would add another 1,000. I told him it was not a good idea to spend that much on a car with a value of 13k. He suggested I add an engine oil additive and see what happens, which I have done. I took a 2 hour drive to allow it mix. This morning started it cold the knock was quite a bit less but still there, after the engine kicks off of fast idle and then goes away.
I will see what happens. Either (hope) it improves or get a different car.
I will see what happens. Either (hope) it improves or get a different car.
Pole Position
Joined: Oct 2014
Posts: 2,561
Likes: 365
From: New Hampshire
$4,000 for cam phasers?? Yeah I'd try that oil additive a couple more times, if that doesn't work I'd trade the car in.
If everything else fails you could always live with it and see how much you can get out of it...as annoying as it may sound I've known many people with many cars that have done the same. Know a guy who has driven his BMW over 100,000 miles with cam phaser noise...he's got misfires and a check engine light. When I ask him how it's running he says...great. After he gets the thing over 10 mph it runs fine (not an ideal situation for sure, but I see this stuff all the time).
If everything else fails you could always live with it and see how much you can get out of it...as annoying as it may sound I've known many people with many cars that have done the same. Know a guy who has driven his BMW over 100,000 miles with cam phaser noise...he's got misfires and a check engine light. When I ask him how it's running he says...great. After he gets the thing over 10 mph it runs fine (not an ideal situation for sure, but I see this stuff all the time).
Thread Starter
Driver School Candidate
Joined: Sep 2014
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From: Iowa
Update: I added one quart of Lucas Pure Synthetic and drove 2 hours. Next morning I would say a 40% reduction in noise. I noticed Lucas recommends one quart for every 4 quarts of oil. This morning took an additional quart out of my car and added a second quart of Lucas. Taking a long drive next week, I will report back .
Note: My local mechanic has removed oil for me so as not to over fill the oil
Note: My local mechanic has removed oil for me so as not to over fill the oil
Intermediate
Joined: Oct 2016
Posts: 346
Likes: 31
From: SC
Update: I added one quart of Lucas Pure Synthetic and drove 2 hours. Next morning I would say a 40% reduction in noise. I noticed Lucas recommends one quart for every 4 quarts of oil. This morning took an additional quart out of my car and added a second quart of Lucas. Taking a long drive next week, I will report back .
Note: My local mechanic has removed oil for me so as not to over fill the oil
Note: My local mechanic has removed oil for me so as not to over fill the oil
Not sure what a "Cam Phaser" is? The IS 250 has a know problem with noisy cam gears. There was a TSB for this but Lexus will only fix it under the original factory warranty (not extended warranty). Is this the same problem?