The car has 99,000 miles and it gets oil change regularly with synthetic oils every 4000 miles. tensioner, idler, pulley were all changed at 38,000 miles. I have always heard this slight tapping noise even when I got the car at 38,000.

What do you think could be causing this faint tapping noise at idle. when warming up it’s still there, but not as noticeable. Thoughts guys?

are you hearing similar noise ?

 

Hello,

Very difficult to say anything without being able to hear the Noise in question, a Video of what you hear would be helpful, otherwise the source can literally be anything from normal operation to a wrecked engine, any guess would be just pointing at the sky.

 

Unfortunately, it’s impossible to even attach a compressed file to the site

 

Not true, there is a long list of valid file extensions. Audio ones include mp3 and wav
But you can also upload to YouTube and share the link

 

Sorry for the delay.

My preferred way of sharing videos here is to upload them to YouTube and add a link to it in the post here, it doesn't require anything by Google Account, and it also doesn't have any restrictions on the Size of the File to upload. You can create a burner account for it if you would like, and you can also publish the video as Private, such that it can only be accesses by someone with a Link to it.

Hope this helps and best of luck!

 

 

Thanks Guys! Take a look at my YouTube shared video. Car runs great and has only 99,000. T/B, tensioner, WP idler all changed at Lexus at 38,000 due to age about 10 years ago and also the car has synthetic oil used and changed every 4,000 miles.

The noise is more noticeable at idle and when cold . I heard Lexus had a TSB with one of the transmission damper or line . Thoughts?or Could it be the Valve lifters ?

 

ENGINE
EG004-05

Title:
FUEL INJECTOR "TICKING" NOISE

Models:
'01 - '03 RX 300

March 4, 2005

Introduction

Some customers with 2001 - 2003 model year RX 300 vehicles may complain of a "Ticking" noise from the engine compartment when the engine is idling. An updated fuel main tube has been made available, and a second fuel pressure pulsation damper has been added to improve this condition.

Applicable Vehicles

^2001 - 2003 model year RX 300 vehicles.

 

No, I sincerely doubt it, this is not a Mechanical Sound, not the sound that would be coming from the Hardware of the Engine. What's interesting, my 2000 ES300 has a similar sound coming from the engine, the only difference is that it's a lot more subtle, to the point where you have to actively look for it to distinguish, which is why I just always assumed that it's part of a normal operation. Yours on the other hand is more pronounced for sure.

This could very well be it, seeing that even Lexus themselves admitted to it, I'm just not quite certain as to why it would manifest itself to such an extent only in RX and not in the entire fleet of cars using 1MZ Engine.

One way to check whether it's the Fuel Line that is at fault would be to Hold it with your Hands when the Engine is Running, feeling for any unusual Vibrations coming from it. Seeing loud the noise in question is, if it is coming from the Line, you should be able to feel at least something. On the other hand, if this Noise is caused by the Resonance in the Fuel Delivery System, grabbing the Line by Hand may also shift the Resonance Frequency of the said Line, which has the potential of Reducing the Noise you hear to quite an extent, possibly even Eliminating it completely.

So in summary, when the Noise is most audible, try grabbing moderately hard on parts of Fuel Delivery System to feel for any Vibrations, or Listen for any Change in the Sound. You can also get a Stethoscope to do so, but the issue is that the Engine Block is an excellent conductor of Vibration, I am pretty sure that you will just hear this noise throughout the entirety of your Engine if you decide to go that route.

If that doesn't help, it may just be worthwhile to go through on the repairs listed in the TSB, depending on how badly would you want this Nosie gone that is.. From all that I could gather, while annoying, it is not in any way harmful to the Engine, in the same way as the dreaded Timing Belt Noise on those engines, here is a thread about it.

Hope this helps and best of luck!

 

could be injectors.

 

How and where do you grab the fuel line to check in engine? Are you hearing reports many RX300 owners have the same issue ?

can you post a video here on your ES300 noise for comparison? Much appreciated fir your feedback

 

Well, I am primarily an ES owner that tends to wander off at times, so I am not particularly well versed in issues specific to the RX models. My logic is that if Lexus themselves issues a TSB for this issue (which meant that they had to perform the repairs for free when the car was still under Warranty), it must be rather widespread. To give you a perspective, despite persistent problems caused by a particularly low Output Current of the factory Alternators on a 3rd-gen ES, Lexus has never issued any formal notice regarding said problems, even if all that's needed to remedy it is to get the Higher Amp Alternator off of Avalon that fits right on.

While at it, I also found a fair few reports of issues with a Ticking Noise in the RX models on several different forums from way back in the day, below are some of the links I got from just a few minutes of searching, all of them reference the same TSB you listed earlier. That said, none of them had any samples of the sound to compare yours with, although some do mention that if the Noise is caused by the Fuel Supply, it gives off a distinct Feedback on the Fuel Rails, which should make it relatively easy to localize.

Fuel injector noise rx300, Lexus has update
Fuel injector noise

If you take the decorative Engine Cover off, you will see the Fuel Rails with a Metal Line that connects them together. Said Line then crimps onto a Rubber Hose, which is then connected to the Fuel Line under the Master Cylinder. For now, just try placing your Hands on both the Rubber Hose, and on the Metal Line, just to see if you can feel anything unusual on them. It's a shot in the dark, but it's a simple enough procedure to try before simply following through on the repairs in the TSB.

P.S. As I was writing this, I looked at the Parts Catalogue for your car and noticed a rather interesting difference between your RX and my ES - the latter has a Fuel Filter sitting under the Hood, right under the Master Cylinder, while with the RX, the Fuel Filter is located on the Inside of the Fuel Tank, encased with a Fuel Pump, with just the Fuel Line that makes it under the hood. In this application, the Fuel Filter can very well serve as a Buffer of sorts, reducing the effect of Pulsations created by Injectors, which could explain why the Noise you hear is so much more prominent in the RX compared to my ES.

ES300 Diagram
RX300 Diagram

Hope this helps and best of luck!

 

Isn't the the high pressure fuel pump/injector ticking noise is primarily on direct injected Toyota/Lexus vehicles?
Never heard of it in a 1999-2003 RX.

 

There is a TSB apparently on the 99-03 RX for this issuec