2021 Tacoma Irregular Tick/Snappy Sound on Acceleration

Hi all,

2021 TRD Pro, 36k miles. Starting this thread in hopes to get answers on a noise that has been driving me absolutely crazy (in addition to the marbles in a tin can sound on acceleration that I'm also going crazy trying to solve but I'll make another thread on that). I've searched the forum and have found/bumped many threads so far on this same sound (or at least same description of it if there wasn't a video) but no answers anywhere, just speculation.

https://youtube.com/shorts/LY6ngWDoUw8?feature=share

This is not Tacoma tick, or the "injector cleaning cycle." This is a completely irregular ticking sound that happens on acceleration with a warm engine. It does not happen at all before the engine is warmed up. It is not affected by fuel grade. Truck runs perfect, doesn't seem to be any change in performance while it's happening. Only happens in drive, will not happen in Neutral. Is usually about twice as loud as in the video but I had to keep it slow so other engine noise/wind doesn't cover up the noise. No codes.

I can replicate the noise by putting the truck in drive, holding the brake and getting the engine to about 1200rpm, although it is not nearly as pronounced as when driving normally. For this reason I have been able to isolate the noise to originating in the engine bay and on the drivers side of the engine, but even with a stethoscope on every part I can reach from above and below I have not been able to get any closer to the origin of the sound. Searching for it in this way also gets the transmission very hot after a few minutes and I don't want to keep doing it if I can help it.

I have been below the truck and banged on/shook every bit of exhaust I can get to. Everything is tight, heat shields are all tight, no rusted bolts or anything else that would cause a rattle. Fan isn't contacting anything, even with engine torqued up.

The noise is incredibly pronounced when driving against a wall, barrier, other cars etc., but is also audible other times as long as the windows are down. I feel like I'm going crazy here because the noise is driving me nuts and nobody else I know who owns a Tacoma has it. Brought it to the dealer who said they couldn't replicate the noise. Once I showed them how to do it (just had to slowly drive up the ramp into their shop) they admitted that it definitely didn't sound normal. They then replaced the belt tensioner which didn't fix it and threw their hands up. I can't waste more time going back to them until I know what the issue is on my own.

Between this noise and the tin can rattle (spark knock? again don't want to hijack my own thread so will discuss elsewhere) I actually hate driving my truck with the windows down and that really sucks because it's such a great truck otherwise. Would love to solve this mystery once and for all for myself and others who have the issue. Willing to dissect this truck as much as I need to to figure this out.

I'll also add that I did come across this youtube video in another thread with someone who had the exact same noise except theirs was doing it while sitting in park at idle. Mine has never done that but something to consider.

 

Alright so I've possibly made some headway here. While continuing to search the forum I found a post that sounded vaguely related, and the user pointed to their PCV valve for their issue. Its only a few bucks so I figured why not give it a try.

So I pull out my PCV valve, and held next to the new one I didn't notice anything too strange. The original had some oil on it of course but as far as the little check valve inside, they felt about the same when I shook them. I put the new pcv valve in and went for a drive, and I still heard the noise. I did notice though that it maybe sounded a little different. So, not wanting to abandon this theory, I decided to isolate the issue by driving the truck with the PCV valve bypassed. I did this by pulling the hose off the PCV and plugging it (the truck will barely run if you don't plug off the hose).

Low and behold, the noise was completely gone. Engine still hot, and had just been making the noise on the previous drive 4 minutes earlier. I drove around extra long and with some spirit to really confirm that the noise was gone, which it was. So I reinstalled the PCV hose, expecting the noise to now come back again.

It didn't. Why, I have no idea. Perhaps there was some gunk in the PCV system that was allowed to be passed by driving with the hose removed? I have no better ideas, but as of now the noise is gone. If I can do my whole commute tomorrow without hearing it I will be fully convinced. Will report back.

 

So unfortunately this victory was short lived. Noise completely returned the next day (sorry for not updating). Maybe I just let the engine cool for too long when I did my test, but as of now the issue is still completely the same. Running out of ideas and the noise is still driving me insane. Some more info:

Will not happen in park or neutral at a stop.
It will however continue if I am rolling and shift into neutral (doing my best to keep the same engine RPM as when it was in drive). The clicking is 100% tied to engine RPM and not to anything in the driveline rotating. It starts when the engine is around 1000rpm and stops around 2000rpm. The hunt continues.

 

Just came across this video as well, which to me sounds like the exact same noise. I don't agree with the comments saying this is the normal injector noise.

https://www.reddit.com/r/ToyotaTacoma/comments/xv01bf/what_is_this_sound_it_comes_and_goes/

 

Here's my noise since the original video is taken down. Can anyone confirm if this is the same noise?

https://www.youtube.com/watch?v=LY6ngWDoUw8&t=13s

 

Since it only does it under load my thought is pre-detonation but since you have no codes I’m unsure. I would check the spark plugs could be a loose plug these engines have been known to have loose plugs from the factory.

 

I have the same issue on my 23 sport, only have 17,000 kms on it. Does anyone know how to fix it?

 

I found a post yesterday (wasnt able to find it today) but it had a similar noise and their dealer diagnosed it as a bad lifter. I'm going to try a different dealer and see what they say.