I have an 09 460 base with 147k miles on it. I have noticed since last fall that as the car is warming up, it will start to make a ticking noise in an increasingly loud pattern. It doesn't happen right away but starts a few minutes after the car has been idling from being left overnight. It will increase to a pretty loud tick until it just stops and starts over from a quiet tick back to loud. If you rev the engine a little, it stops momentarily but will start back. If you drive the car it stops and won't come back, even idling, until the next cold start. I don't normally notice it because I don't usually leave the car running and happen to be outside the car to hear it.

This morning was really cold, so I started it early. As I was loading my car for a trip, I noticed it wasn't really doing it, except a few faint ticks. The only difference is I realized how dark my brake fluid was last night (about like a darker ice tea), so I did a poor man's siphon and refill of around 16 ounces. I want to get it flushed properly, but I'm over an hour from a Toyota or Lexus dealership so I can't right now. I don't know if that affected the tick, but it didn't happen today like usual. When I tried to listen to it with the hood up yesterday morning, it seemed to be coming from the right upper side, so I guess it could have been the actuator. I don't know mechanics as well, so I don't know if an actuator runs without using the brakes or not.

I attached a quick audio clip of it.

Any ideas?

 

That sounds like Toyota timing chain slap to me.

 

Ticking is usually an injector or a high pressure fuel pump. These usually don't go away, though. Hard to tell, really, from the audio.

 

Doesn't chain slap get louder as the RPMs rise? OP said the noise goes away when he revs.

The ticking sounds like the HPFP (common noise with DI engines) and I've found that octane will often affect the ticking sound levels. Did you get different brand gas or octane recently?

 

When a tensioner is the problem it will because there is big difference between oil pressure at idle vs 2k rpm, Toyota's spec for oil pressure has always been around 2500 rpm.

 

I have been using mid-grade or regular lately. I quit using Premium a while back because many others said it'll run fine without it including a Lexus dealer (he said he only uses regular in his LSs). I guess I can try a couple of rounds of it and see. This sound is only on the right of the engine that I can tell.

 

I think that's the issue. Sure, reg/mid will run fine in your car (the ecu will compensate) but some side-effects of lower octane is a louder HPFP/DI injectors.

 

if this is the issue, Is this a serious issue that needs addressed asap? My brother had a 91 Q45 that had a random failure of the timing chain tensionor and ruined the engine.

I am strongly considering getting rid of this and getting a Highlander, anyway. This might increase the urgency.

 

I guess when it warms up it isn't as bad?

I'll go back to premium for a while and see if the sounds go away.

 

What oil? What fuel? Any engine work done recently?

 

Yeah, it's louder on cold starts because the RPMs are higher; the ticking subsides once the idle drops back down.

 

Full syn oil, just changed a little over 1k miles back. This issue has been going on since last July/August when I first noticed it. I had already started putting in lower grade gas by that time, but the octane has bounced around some.

No engine work since I got the car, just suspension work and rear hub.

 

What oil? Sorry but 'full synth' doesn't mean anything.
It sounds pretty bad, not pulling punches...
Can you try localizing the source of the noise? Is it heads? Front timing? HPFPumps?

 

Depends, there are lots of threads that are about this issue just google search for ls460 ticking noise clublexus and come to a conclusion by yourself. I don't really think fuel type or brand can cause the hpfp's or injectors louder, maybe someone can explain that to me.
Also the audio you posted sound like the car is idling to me not revving up, when you say right side is that you looking at the engine from the front of the car?

 

Do you mean the video? Should be 5-20, but I don't know the brand. A local quick-change place does it. But I have had it done at multiple places during the time the noise has started.

It appears to only be on the upper side of the engine and is loudest on the right side. The HPFP seems to be the most likely thing since the sound goes away. If it was physical damage or a failing part I would assume it would happen at the same RPM regardless of how long the engine runs.