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Discussion Starter · #1 ·
Today, on initial, cold startup, the engine made a distinctly different valve-train like tapping noise. It lasted 2 minutes while I pulled it out into the driveway and investigated, then it disappeared. Outside and water temperature were 45F. 2800 miles on the car. Hasn't happened previously. It's currently at the dealer, for them to check out tomorrow morning on first start. I expect tomorrow it will not do it, and I'll have nothing to report, but I wanted to get it documented and looked at.
 

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Most cold startups I hear a metalic "chain slap" for a split second, I assume its some sort of hydrolic tensioner that has lost pressure thus making noise until oil pressure can fill it back up... Or just a noisy starter release.

I have been waiting until the first oil change is scheduled to bring it up during service.
 

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Discussion Starter · #3 ·
The dealer of course heard nothing on startup today. I didn't expect them to, as it has only happened once. But, it's in their history now.
 

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Most cold startups I hear a metalic "chain slap" for a split second, I assume its some sort of hydrolic tensioner that has lost pressure thus making noise until oil pressure can fill it back up... Or just a noisy starter release.

I have been waiting until the first oil change is scheduled to bring it up during service.
i hear the same,if you keep your door open to listen upon startup,i hear the same mentioned noise from under the car,i thought maybe a heat shield or something rattling????
 

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I hear the same sound when i do a cold start up. I too plan to have the mechanics check it when i take it in for its first service
 

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I am at 2,000 miles. I have heard it several times now. My first thought was the starter. Next time i am in the neighborhood, i will stop by the dealer to ask some questions.
 

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I would think that the mechanics would "not hear" what you are wanting them to hear, because then they would more than likely have to fix it for free.

It would be best, if at all possible, for you guys to be there when they check it out, so you can point it out.

I'm not trying to say that they would lie, but it seems like they could claim not to hear it and tell you everything is fine, and send you on your way.
 

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Engine noise @warm up

I just now have 350 miles on the odometer..... when engine is cold, mine
makes that valve train rattling noise, and goes completely away when
motor is warm....and it has done this right from the git-go when I first
started it at the dealership prior to buying it. After reading this with the
number of people reporting the same thing, it is starting to seem like its
just characteristic of our motors.....I guess time will tell??
 

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I think it is the Valve train too
It sounds like the Hydraulic Lifters are not pumped up full of oil while cold and making some valve train noise. I have heard this too my IQ has almost 4K miles
 

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I think it is the Valve train too
It sounds like the Hydraulic Lifters are not pumped up full of oil while cold and making some valve train noise. I have heard this too my IQ has almost 4K miles
I too have had the same experience and I have nearly 5000 miles on the engine. This has been there since I had the car. As "wesgl" said, I too figured it was just a bit of hydraulic lifter clatter before they are under full pressure.
 

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Mine does it when its cold, yours does it when its cold, they ALL do it when its a cold start-up.
Yes, I think it has to do with the VVT of our motors...it always goes away once the motor is
warmed up. Mine has done it since the day I drove it off the lot.....I'm just not worrying
about it, its under warranty. I think that it is characteristic of our motors, at least until I hear
otherwise....

My 2010 Kia Soul Sport did it from day one also....it never developed into a problem....
 

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Discussion Starter · #12 ·
Currently I have about 5,000 miles on the car. Starting at about 4,500 miles after a cold start there is a distinct valve-like tapping noise until the car reaches about 120F. It's particularly loud when coasting, off the throttle, and the first 4 minutes or so of my drive is downhill, coasting. And, this is a quieter noise than the one time event I had at the start of this thread.

The sound is RPM related, and sounds like old style valve tapping. That it's a new sound is what is particularly troublesome for me, and I've taken it to the dealer. Left it overnight and sat in the car with a mechanic the next morning, and he agreed it seems unusual, though they actually have very little experience with this engine.

My personal guess is it's something to do with the VVTi technology and the sensors for temperature. I don't know exactly how this engine works, (no hydraulic lifters though), and it may have both an electric motor and an oil pressure (hydraulic) control of the intake and exhaust valve timing. If that timing is off, or not functioning at the correct temperatures, it may be the cause of the noise that disappears at 120F. Just a guess.

The car is still at the dealer a few days later, waiting for word from Toyota HQ on what, if anything, to do about it. They actually sent a recording of the noise to Toyota but have not done anything physically to the engine. Their canned answer is "It would give us a code if anything is wrong." Uh huh.

As previously stated in this thread, there are no TSBs, Toyota Service Bulletins, covering this issue. I'm documenting it early though to cover me beyond the warranty in case anything crops up later. Personally, I'd recommend that to anyone else too. The more owners who document this, the better it is for everyone.

I'll let you know what the outcome is.
 

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I'm an old believer in warming up my car before driving it.....but, I'm sure that what you are
hearing is the same warm-up noise that I posted about in a couple of posts above....I now have
almost 2k on my odometer and it is still there, maybe a little louder now during the warm-up, but,
it still totally goes away after the engine is warm. I don't drive mine until its warmed up and that
noise has gone away.

Maybe you should print off this thread to show your mechanic....this is common for our iQ's and
surely somebody out there can shed some light on it as to the reason, and if it needs to be fixed
before it prematurely ruins our motors?? Even though we have not experienced a problem, other
than being a very annoying noise, something just isn't right? It needs to be addressed!

Keep us posted....and good luck!
 

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Discussion Starter · #14 ·
Just this minute got a call from the Service Advisor at the dealer that they have HQ authorization to start tearing the engine apart. More news next week.


IMHO there is not a shred of evidence that warming a car up prior to driving does anything other than waste gas and make it more comfortable on a cold day. But, that's probably a topic for a different thread.
 

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As far as warming it up, to each-his own. The only reason I mentioned it is because thats how I
knew that our iQ's made that noise when warming up from the day they were new, and thats
also how I knew that the noise went completely away after warming up.
Most of the people here are like you, they get in, start it, and drive away which makes it more
difficult to hear when the noise starts, and when it goes away.....I just thought it might be
helpful to you and your mechanic to know that the noise is inherent in our iQ's right from the
factory. I wasn't knocking you for driving it your way, just the more information you have , the
better....
 

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Discussion Starter · #16 ·
Ahh...but you see, mine didn't make the noise for the first 4,500 miles, which makes it something new and different. And, I know at what temperature the noise goes away because I monitor the engine temp with a Scangauge, and have from day one.
 

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Ahh...but you see, mine didn't make the noise for the first 4,500 miles, which makes it something new and different. And, I know at what temperature the noise goes away because I monitor the engine temp with a Scangauge, and have from day one.
Are you sure....the day I bought mine, and before I drove it home, I heard that noise
when it was warming up. The next day, I came back and went to another new iQ on
the lot, started it, and it made that same noise while warming up. I know that the very
few times I have driven mine without warming up, I could not hear the noise from
inside the car unless I was stopped with the windows down and the motor still cold......
just my experiences.....thought it might help??
Oh, one other tidbit.....this noise doesn't appear until about 30 seconds after you first
start the car with the engine cold, then it starts talking to ya....it gets louder and louder
to a point, then it starts going away....until its completely gone which takes about 5-10
minutes to go completely away, however long it takes the motor to warm up.
 

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I am at about 8000 miles and still make the noise on cold starts and some hot starts, the noise never last longer than 5 seconds.

I will bring the start up noise to the techs when it goes in for the oil change in a month or two.


Please keep us updated on what the techs find.
 

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Whats the update on the engine tear down? Mine just started making this noise this morning with 2500 on the clock. Didn't sound like anything real bad, but if it is, I would like to know.
 
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