Occasional rattle coming from engine bay during acceleration

I think it is pinging/spark knock. Mine almost 100% goes away when using 93 octane, only for a second I'll hear it and it's usually in hotter weather. I just want Toyota to admit it.

 

Personally, I’ve ran 93 before and still had the noise happen with me.

My last oil change I put AMSOIL in it, supposedly it is 100% preventive for LSPI. I still heard it but not as often or loud.

fruit for thought, a friend of mine mentioned that it could be the VVT solenoids clattering during acceleration.

I could throw in 5w-20 for my next oil change and see if it goes away entirely.

 

Which Amsoil did you use? Signature series 0w20? I'll give it a try. I see where they advertise this but I don't see how engine oil prevents pre ignition.

 

I used the OE series oil, but yeah I'm not really sure either. I think LSPI is a different kind of pre ignition than what's being talked about here.

 

Has anyone made any headway on this? My 2021 has been doing this since I bought it at 24k miles. Putting premium gas in seems to have no effect. Dealer threw their hands up.

 

The noise in my 21 completely goes away with premium. It's diminished some with 89, but for the most part I just live with it unless I'm towing on a long trip. I'm not feeding this truck premium gas, way too expensive.
I have noticed during colder weather I don't hear it at all. The hotter the ambient temp, the worse the rattle, but like I said, completely gone with premium gas at any outside temp.

 

Could be a metal ac line

 

My truck did this since day one and I'm at 80k miles now. My guess is that it's the the drive shaft knocking back and forth between being drive and coast. The drive shaft has a tiny bit of play and it feels like when I'm coming off the gas and transitioning from pushing to coasting, it hits the sweet spot in between the two and bounces back and forth. That's just what I think it is. Easier to replicate on a manual.

 

My 20 with manual has the same sound got it at 38k miles now at 113k mi.

 

I have 20K on my 23 been running Chevron 93 since it had about 3K and it’s smooth and quite through any RPM range.

 

Anyone ever notice this with ECT mode on? I've been using it more often lately and haven't heard the noise with it on.

 

So I've reset my trucks learned data with a SnapOn pad, and so far I haven't heard the knocking.

I did notice on the fuel injection data that it looks like my actual vs target fuel pressure was a lot higher whilst revving. Idk if this is because the injectors are switching between direct & port, or if there is an issue with the fuel system.

 

My '22 has done this since day one. Been running 93 octane for a few months now and maybe it's a little better, hard to tell.

I assumed this was "lugging", the High Load / Low RPM stuff that happens when I drive without smashing the accelerator enough. I try to baby it but maybe I'm too good at that and should drive a little harder like a normal person.

 

OP did you ever determine the issue? My 23 started doing this at 11k. Is very hit or miss when it happens. Seems to subside to some extent during the cold weather as you pointed out.

 

Not exactly, but I used a snapon scan tool to reset all of the vehicles learned data, and the rattle seemed to subside substantially.

I think our trucks start to spark knock when it gets hot, and during colder weather it doesn’t happen so often.

With your truck being so low mileage, I would take it to a dealer and advise them of it. If they can’t figure it out, call Toyota so you can get it documented or possibly see if they can send a rep out.

I’m at 80k mile now, and the engine hasn’t blown up yet so that’s a good sign lol. But obviously, spark knock probably isn’t that great for its longevity.

One thing I will note, when I using the scan tool I observed that the actual vs target fuel pressure was way off. Leads me to believe there might be something up with the fuel system. Maybe that’s something you can mention to the dealership?