Rattle on startup when truck has sat for 24+ hours

I have a 2020 SR5 with the 5.7 Miles. Currently 6500 miles.

I've noticed that if the truck sits more than 24 hours give or take it will sometimes make a fairly loud rattle noise from engine area for like 1 second or so immediately after it starts up. If I drive it every day it doesn't do it, but if it sits for a day or so it makes the noise. Almost like what i imagine timing chain rattle would sound like?

Is this normal for the 5.7?

 

Mine does the same thing...2019..I just drive the hell out of it...lol

 

I haven't let mine sit that long honestly, and I only have just over 500 miles on so far, so idk if it's normal. My suspicion would be is the oil is draining out of the top end while sitting and back down to the pan, and it's a slight moment of valve chatter until the oil pressure builds and gets back up there.

 

Nope, mine doesn't do it.

 

Kinda what I was thinking too. Just didn’t know if it was something to worry about or not. One reason I bought a Tundra is the reliability. So if it’s noisy but runs fine I don’t care

 

If it’s the same sound I think you’re referring to I think it has to do with the air conditioner. It’s done it a few random times. I don’t drive the truck a ton. If it sits for a while and I start the truck with the a/c on it will make a god awful sound for a second.

The other day I started the truck and I had to ran back to the house to grab something and it made the sound. It sounded a lot worse from outside the truck. I yelled back at my daughter “what the heck did you just do” because she was touching the console. “All I did was turn on the A/C dad”

It seems if the A/C isn’t used for a while it will do that when turned back on.

 

My current tundra is my 3rd tundra and 8th Toyota.

They have all sounded “cringe-worthy” upon start up.

Give it 30 seconds or so..

 

Ah you know that’s something I can test. I have the habit of turning the truck off with the air con still running in auto.

next time I’ll turn it off and see if it still makes the noise.

 

This is like literally a second maybe 1.5 then it’s just normal noises.

 

That is probably the a/c compressor as other stated.

I was simply stating that every Toyota motor I have owned has been loud and chatty upon a cold start.

 

Mine does it too. Definitely a different noise than the normal toyota engine noises. Only does it for a couple seconds on the first start after the truck has been sitting overnight. Certainly sounds like valvetrain or something oil pressure related. My engine warranty expired last month, so it's making me a little nervous. Someone with a truck still under warranty should take theirs to the dealership and report back.

 

Ive tried twice to catch a vid of the noisy A/C compressor clunk lots of us seem to occasionally have, like usual when you want it to do it, it won't. Its definitely annoying, but i don't lose sleep over it.

 

Yeah I drove a 16 4Runner before the Tundra. Toyota engines may not be the quietest but they last forever with a little mainenance. Thanks for the input

 

I've heard the a/c noise some of you are talking about, and this is something else.

 

My guess would be a valve lash adjuster leaking down a little bit when the engine is off. Extra rocker clearance on start, tap tap tap. Not a worry unless it lets the rocker arm fall off which is super rare. From the threads on here it seems nothing actually breaks when that happens, the rocker just lies in there while the vehicle throws a code and has a loss of power. I used to drive an old Nissan that drained and collapsed all of them overnight. It would sound like a diesel tractor every morning for 1-2 seconds and then purr like a kitten the rest of the day. The car fell apart but the motor never gave a single issue in 200k miles.

There was a youtube video where 9 of the 16 rocker arms in a Corolla 1.8L were sitting in there but for that many to fall it was likely from shifting into 2nd at 90 mph. He must have floated every valve clear to France for that to happen.

 

mine sat for 4 days tapped like lifter bleed down, 54,000 miles on it. first time for noise. definitely caused by oil draining as soon as oil pressure came up a couple of seconds, quiet, running 0w - 20w synthetic ( mobile 1 ) any body running heavier oil? outside temp was 55 degrees. it may not bleed down as fast with heavier oil

 

Not mine. But this is closest I could find on YouTube. I’ve never heard mine from outside.

https://youtu.be/6qxrNLwlRo0

 

Could it be this?
https://m.youtube.com/watch?v=i75_kA6PPJI

 

I bought my 2016 Tundra 5.7L certified used last February. I noticed the cringe worthy noise shortly thereafter when I hadn't driven the truck for a few days. I let it sit a week determined to have the hood popped and video the noise. Never could replicate it and I've never had it happen since. My truck will sit for days if I decide to drive my Tacoma. Still have never heard the noise since. Not sure how to explain it.

 

Maybe. I think first time I experienced it I also felt pulse in brake petal (small one). I have keyless start so I have to have foot on brake. I’ll try and lay more attention next time. Thanks

 

I religiously start my cars with a/c in off position.

That said I have owned 4 different 5th gen 4runners and in the right conditions on initial cold start, the a/c compressor would make a rattle on initial engagement. It was found to be a tiny bit of vapor/liquids passing through.

I've noticed the A/C compressor on my PRO is noisy.

I would try a few cold starts without the a/c on and see if that rules the issue out.

 

Yes...this is the sound I'm referring to in my other 4runners. Some were a bit worse than others.

 

I’ve heard the same noise on my 2010. It’s worse in person. Usually happens when it’s cold out and the truck has sat for a while. I also heard it the next morning after setting up camp in the sierras (was about 24F at night).

 

Well I’m almost positive it’s the AC. Turned off AC before I shut truck down. Cranked it up today and no issue. Hit the Auto button on HVAC controls and it made the noise for an second.

guess it is the compressor.

are they normally loud on our trucks? The one in my 16 4Runner didn’t make that noise.

 

I just noticed this diesel-like rattle on my 2020 yesterday for the first time. However, I noticed it when my truck was warm, not cold. I had backed partway up my driveway (after driving for about 30 minutes) and shut the truck off to unload some stuff from the bed. When I started it back up to park properly, that's when I noticed the noise. A/C was not on at any time. I think I'll just keep an eye on it for now and maybe switch to 5W-30 (or 0W-30 if such a thing exists?) when my warranty is up to see if that helps.

 

Sounds like you guys have top end rattle due to low oil pressure on first start up. Unless you have old oil or wrong oil filter then you have an issue. Next time before starting it pull the EFI fuse, crank it for a few and then put the fuse back in and start with oil pressure. If noise goes away, that's your issue. It could be a reprogramming issue, so if they reprogram it to crank longer before starting, that will fix it. Had the same recall on Chevy trucks when I worked for them while back, they also sold Toyotas, that's why. We installed a new prom and different oil filter and fixed the issue.

 

I thought I read up somewhere on here before about a timing belt slap. Could it be that?

 

My 2019 has done it a couple times. It is not normal valve tick. Our engines are a little noisy and all Tundras I have heard are a little noisy. Our Toyota 4Runner is also a little loud as far as valve tick goes. Both our vehicles have been doing it since day 1 off the showroom floor as both were bought new.

The noise is for sure 10,000 percent sure not AC compressor. It is straight metal on metal rattle and last for .5 second to maybe a second then settles in with normal valve tick.

When it has happen to me, the truck has sat for a week or maybe a little more. We took an 8 day vacation to Disney. Came back and went to work the next day. It made this noise when I started it and went 9 days without starting. It is really loud too for that .5 second!!!!

Other time I was in NC for business and had been sitting for about a week.

Again it is a split second and it is loud! My driveway is decently steep so truck is on a slope so that probably contributes.

It probably is due to the 0w-20 has time to sink completely to the pan from the top end over that long of time.

 

Because of lack of use this past month, I’ve had lots of experience with this noise. It only occurs if the truck has sat for more than 24 hours. It is loud for about a second and then goes away. It isn’t an air conditioning noise as I turn the a/c off.

Here’s my noise:

 

That is the exact noise I hear as well...I also don’t start with AC on.