What is this noise coming from the engine bay?

There are two videos attached of a 06 tundra 4x4 being started (I'm considering purchasing the truck). The first video is a cold start and the second video is after it's warmed up.

There are two things that I find concerning in the video.

1) Maybe I'm wrong, but does the idling RPM sound excessive on the cold start?

2) There is a strange noise in the first video (19 seconds left video). I haven't the slightest idea what that could be.

Edit #2: the first upload was too long. The first two videos are from a cold start (they're backwards though- video 2 is the initial start, video 1 is a continuation of video 2), the last video is after I was warmed up.

https://imgur.com/a/yL7DKql

 

No videos ...

Note, in the megathread, there is a TSB about noisy cold startups.

 

Whoops. edited the post and added the videos. Will check out that thread. Thanks!

Edit: had to do a second edit to fit the videos in the upload.

 

I need to put in some ears to listen more closely. The first vid almost sounds in my Bluetooth speaker like a loose vacuum hose.

 

So the issue 1st video is the secondary air injection pump. It runs for the 1st 30 seconds from a cold start. You hear it whistle as it spins down at the 19s mark and all goes quiet. It doesn’t mean it’s going to die soon. It’s a fact of having a 2005-2006. Replacement is $650 last I checked. It lives under the manifold. Not a fun repair. Bypass kits are available but I don’t recommend. Hearing this would not dissuade me from buying. But I would notify the owner, the secondary air injection pump sounds like it’s not happy, and ask if it has ever thrown codes for the SAI system.

EDIT: had wrong timestamp. Updated. I don’t hear anything else concerning here.

 

Thats interesting. I’ve never heard mine kick off like that. Or heard mine before… hopefully mines not broken.

 

Interesting. The guy said he also has a 2016 GX460 that makes the same sound (video attached). They sound pretty similar to my untrained ear. He said he has not had such codes. Only time he said he's gotten the check engine light was for the o2 sensors, which have already been replaced.

https://imgur.com/a/Ou96KOk

 

Not talking about the pulsing sound. Go the 19s mark of the 1st video you posted. Do you hear that whistle? It sounds almost like a turbo whistling/blowoff valve sound.

That's the SAI pump. It's used on all VVTi 4.7L V8 2UZ-FE engines, which for our trucks was 2005+.

 

Are you talking about the 19 sec from after starting or when there's 19 sec left in the video? If you play the video within the thread, it counts how much time has elapsed. If you open the video in Imgur, the video counts down showing how much time is left in the video.

 

I went to imgur, and when the 1st video gets to 19s on the screen, there is a very distinct whistle sound. You can’t miss it. After that sound the engine runs quieter. It’s the SAI pump, and that sound is a sign that it’s potentially going to fail at some point. The pulsing you may notice goes quiet after. Just listen closely on the 1st video, a little after halfway.

 

At imgur, it’s right at this point on this video. Right when it drops from 20s mark down to 19s mark. That whistling sound is the SAI pump spinning down, after having run for its initial 30s period. It only runs when the engine is cold, and it’s an emission system, so when the pump or its valves die, it will throw codes.

 

I heard that sound too and thought it sounded out of place. But I had no idea what it was.