Occasional rattle coming from engine bay during acceleration

Yeah it could be unrelated to that.

A friend of mine has a 2021 Tundra and his truck makes a similar noise during acceleration. Not as long as mine however.

 

I had those pulleys locked at and didn’t hear any issues

 

Op just out of curiosity. Have you tried replicating this issue using premium gas?

Mine do that mostly during the summer. I thought I might be experiencing pre detonation and started using premium during the summer and that noise just stopped happening. Maybe give it a try before going back to the dealership

 

For my last 3 fill ups I filled up with Shell 93. Two of them I put a bottle of fuel sys cleaner.

It felt like it made a difference in performance but I still heard that rattle, not as loudly or occurrent as before though.

I'm due for a oil change here soon, and was planning to flush the trans and drain/refill the transfer case & diffs with that.

Somebody on here had mentioned that he experienced a noise similar to mine and that it went away after he regeared his truck.

 

Well I would love to know what the dealership says. And it's true I do hear a similar rattle on mine too but mostly when I use regular gas and it's hot outside and on premium it rarely happens and if it does it's very faint.

Keep us posted

 

It definitely sounds louder during hot weather and 87 gas.

Must be related somehow, but not sure.

After this service I’ll probably get a tune up at 60k and see if that makes a difference.

 

OP did you ever figure anything out? I have this exact same noise happening in my 2020 with 63k miles and it happens under moderate acceleration, mostly after making a turn and accelerating. Took it to a shop and 2 different techs rode with me and couldn't hear the noise. They lifted it and saw the skid plate was a little loose on one side but after tightening it, it's still making the noise. Couldn't find anything else. Driving me crazy!

 

I still haven’t been able to find the source of the sound! A few months ago I installed a Radium Catch Can system and that seemed to make the noise a bit more quiet but nothing major. For me, it starts to become more frequent as the weather starts to warm up, because in the winter months I rarely ever hear it. I don’t know if the warm weather + humidity has anything to do with it. I’ve kinda started to live with it since my truck seems to operate fine. If I had a take a guess at what it might be, I would say possibly related to the fuel pump or something internal with the engine since I did find a forum post online with a Mazda driver having the same sound, people on that thread seemed to be pointing towards the balance shaft.

 

It’s louder than most 3Gs are, but it sounds like it’s pinging. Especially since in that video it’s under throttle while the truck is shifting up which is a high load/low engine speed situation.

Also, the Tacoma doesn’t have a balance shaft. I’m guessing the Mazda people are talking about a MZR.

 

I poked around some more and noticed something sticking out of one of the holes of the lower control arm on it's underside. I can't tell if it's a bolt or an oddly shaped pebble as it disappeared when I tried to get it out with my finger. Not sure if this is the source yet but definitely something moving around that shouldn't be there. Either that or I just discovered a completely separate new issue. The plot thickens..

 

This is probably a separate issue, but if I bang on the floor behind the passenger seat, there's a loud rattle from the exhaust heat shield under that area. It wasn't obvious where it was rattling from and I haven't had a chance to really look for it yet.

Also, the front two bolts from my factory skid plate were missing when I bought the truck. I guess the oil change place was too lazy to take off the air dam to change the oil (I don't blame them, it's a stupid design). I don't think I ever heard it rattle, but it would be easy for it to if it's just hanging by the hooks.

 

Mine has made this sound since new but I havent been able to get recorded. I notice it in the same situations, low speed under acceleration. I haven't asked the dealer about it but I am coming up on an oil change soon so I think I will try to get it recorded and ask.

 

I have a 2020 TRD sport. It makes that exact rattling sound like your video. Did you ever get it figured out? Mine started around 19k. I've taken it to 2 different dealers. Both said " unable to duplicate". I think I've had it looked at 3 or 4 times. Extremely aggravating. I'm at 51 k now .One time they said it "could be" a fuel pump knocking. It's actually on the service report. Let me know if you've figured yours out. I'm going to email corporate with all the service records. Thanks

 

I used to hear this same noise very occasionally myself, now I hear it about 100% of the time when accelerating out of a roundabout. It seems that turning both left and right back to back (going around roundabout, then exiting) and then accelerating triggers this. I just hit 15k. The fact it is getting worse is concerning.

 

Sounds like ping to me. Fill up with premium and I bet you never hear it again.

 

Doesn't really sound like pinging, and an 18 month old Taco with 15k miles shouldn't be pinging and I do not wanna pay for premium

 

I am not going to argue about it; but yes it sounds like pinging. Like rocks in a can. Sometimes it is almost a musical ringing and sometimes, like this, kind of a dull but rapid rattle. Those of us who used to adjust timing by turning the distributor know the sound very well. It is very brief here though. And the fact that it only occurs under hard acceleration and lower rpm tends to confirm mild detonation. These trucks are sensitive to octane. I know the manual claims regular is fine. It probably is. But premium makes the V6 happy.

It will only cost you a few bucks to rule detonation in or out.

 

Try premium over donkey piss and report back

 

Thanks for the feedback. I'll try the premium just to rule out. It would not make me super stoked with Toyota.

This is my first new vehicle after 30 years of used Hondas and Fords that treated me really well.

I got a 99 Explorer 4x4 around 2006 and drove it till 2016, put around 150k on it after getting it with 100k and the only issue I ever had was enduring the constant jokes about it being a Ford Exploder.