NEWRXOWNR

Cruiter, My sound only happens when I accelerate. I started it this morning, and there really is no sound while idling. Even opened the hood.

Once I start actually moving is when I hear the sound.

I tried video taping it a few times. I posted a video on YouTube, unfortunately, there were a few issues with this taping.

1. The sound wasn't as prominent that day
2. It was raining
3. The sound even gets further washed out while posting to YouTube.

You really need to listen very closely to even hear it, you may need good headphones. I'll be honest, I saw it just on my computer speakers turned all the way up, and I couldn't really hear it. It sounds louder on my iPhone than on YouTube.

http://www.youtube.com/watch?v=tT-mdWi4-Uc

Cruiter

Sorry, all I could here other than sounding like you were accelerating with your foot on the brake was your turn signal. What I was talking about was a cold 'idle' sound.
Have you gone to the dealer for a diagnosis ???

NEWRXOWNR

Cuirter,
Haha, I thought the same thing when I heard it on youtube, it is definitely barely audible (probably can't hear it at all) in the Video on youtube, much more apparent on the actual iPhone where I recorded it. I am going to look into some video software to see if I can make it louder in the video.

Maybe our sounds are different? Mine is only when you accelerate. The engine sounded fine when it was in park and it was idling. Only when I drive do I hear the issue.

It was also MUCH louder when it was colder outside.

Thanks again for your responses. Hopefully, I will be able to show the tech the movie and have him listen to it on the iPhone itself. I am having it looked at on Wednesday, I'll see what they say.

4482

Mine has done the very same thing since it was new. I have @ 10K on it now.
I think it has something to do with the new synthetic (0x20) oil now being used. The sound has been reported ever since the 2010's came out.

NEWRXOWNR

4482, yours is very similar to mine (2010 Tungsten Pearl AWD RX 350 with Luxury package and NAV).

Is your noise the same? I know it is hard to know for sure without hearing it. Here are the characteristics:
1. Most evident on a cold start
2. Louder when it is colder out side (30 degrees or below)
3. Only seems to happen when you accelerate in gear. I cannot hear it really in idle. This is the key differentiator between what I am hearing and perhaps what others are hearing.
4. Goes away after 5-10 minutes of driving.

If this does sound the same, have you ever reported it? Just curious.

Thanks for your response

4482

Yes to 1, 2, and question 4. As to your question 3, I can hear it a little at idle.

I've not reported it myself to Lexus because I've read on this forum that other have, and it's been explained enough to my satisfaction. My feeling is that with the synthetic 0w20 oil it's protecting my cold engine better then regular 5w oil does at cold temperatures. I can put up with the little temporary clicking sound knowing my engine is being better protected.
I'll be the first one to change my opinion if down the road the sound and synthetic oil is determined to be harmful to my engine.

We all have the option of going back and using regular oil to block the sound. I've always heard and read that synthetic oil is the best oil you can use.

MEP7557

I could hear the sound, I think. It sounds like a loud exhaust note. The exhaust systems on the RX are not quiet. That however sounds louder than it should. The fact that it goes away when it gets warmer could be an exhaust leak/ gasket. As the engine and parts warm the leak would close. I did not hear actual 'ticking' or 'knocking'. If that is the case it is definitely the engine.

I had that 'knocking' noise on cold starts when I first got my car. I changed the oil and filter at 1750 miles and have not had that sound near the levels it used to be at. I did use Mobile 1 full synthetic 0-20. I now have 5k on the RX.

afpj

We have 45k miles on our 10RX350 and have had that noise from day one. Best description was a diesel engine type noise only when stepping on the gas, only when cold. Don't hear it at idle (or at least it's quiet enough that with window down in the car can't hear it). In our GM truck it is called piston slap, and is a common noise. The only thing that has made it go away for other GM owners is using twc3 rated 2 cycle oil mixed into the fuel (1 oz to 4-5 gal fuel) based on someone's extensive research:
http://www.ls1.com/forums/showthread.php?t=91206
I have no intention trying this on the RX, but I haven't really worried about it all this time (or mileage as it were). Whether piston slap or timing chain, it has not changed during the past 2 years except it's less noticeable in summer (when it's 115 degrees outside). If my engine pops a valve at 50k, I'll let you folks know...just a few more months for 50k miles!

NEWRXOWNR

Well, I took the car to the dealer. The dealer told me that the sound was the fuel injectors, and that the sound was common on the car. I want to try and get some more information on why the fuel injectors are louder when it is cold.

Not much I can do at this point. I tried video taping the sound, and it just isn't that bad right now. With the warm weather coming in, the sound just isn't that pronounced, it's hard for me to make a case.

I'm going to have to wait until winter and see if the sound becomes loud again and take it back in then.

The worst news of all is, my bumper needs to be replaced. Evidently, someone caught it real good with their door. I had the car all of 2 weeks when it happened. They hit it in the exact right spot to break a clip that is attached to the bumper. The service advisor said the whole bumper needs to be replaced, the price is about $1100.

Fortunately, I know a collision guy, I am going to get another opinion before I do that.

This is definitely NOT the beginning I was hoping for when I bought the Lexus, *sigh*

rxets

I have my RX10 for almost 23 months. My mileage is about 23k+ now. Mine has all the symptoms (1~4) and it's very noticeable when I start up the cold engine insides the garage since the day 1. I called it "the diesel engine". As for #3, I don't hear that ticking sound as your video plays, but my engine does sound louder in the first few mins. As for #4, the noise goes away as soon as the engine temperature reaches the half of its gauge - its working temperature. Then, the egine and the cabin are much quieter than any cars I used to drive.

Notes: (my car conditions)
*used to drive a lot (10k+ in first 6 months), but not anymore.
*frequently drive in stop and go conditions.
*often drive with the green eco light.
*got the oil replacement and maintenance services by Lexus dealers at 1k, 5k, 10k, and 20k services.

*2 of friends driving the same RX10. They don't believe this sound/noise bothers them. 1 of them thinks it's a little louder. Another doesn't feel too much difference. Perhaps, because we all live in the city, we have higher tolerance!?

oball2400

I agree-the knock or ping is there. We have 33,500 miles on our 2010 and have had this sound for the last 6 months or so. Since we did not have it the first 30,000 miles I don't see how it can be "normal." It sounds like a diesel and is irritating and disappointing to hear it in a Lexus. I hope to find out something at the 35,000 checkup. The dealer I use, Hennessy Lexus in Atlanta, solved my steering wheel rattle problem, so hope they can get this problem fixed.

NEWRXOWNR

Thanks everyone for your replies. Please post if you have any change. I am going to follow up in the winter, when the sound is louder. I just don't have any "evidence" right now, so I can't really expect the dealer to do anything.

yahj

Do you use regular or premium gas?

I found this
"Your vehicle must use only unleaded gasoline. Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance. If 91 octane cannot be obtained, you may use unleaded gasoline with an octane rating as low as 87 (Research Octane Number 91). Use of unleaded gaso- line with an octane rating lower than 91 may result in engine knocking. Per- sistent knocking can lead to engine damage and should be corrected by refueling with higher octane unleaded gasoline."
At minimum, the gasoline you use should meet the specifications of ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada.

offroad200

Apples to oranges I know, but if it makes you feel any better, my old (1987) BMW has piston slap. It's goes away after it's warmed up. It's running great at 280k miles. As some here has mentioned old technology and maintenance, I have to get my valves adjusted every 15k miles and timing belt every 50k. Maybe that makes you feel better.

NEWRXOWNR

Yep, I use Premium gas; however I cannot say what was in there before I got it. I just put in the second tank full of premium. We'll see again how it goes this winter.