Knocking Sound When Idling in Gear

It has to have something to do with brakes or transmission, though right? It doesn't happen in park, or at least, I've never noticed that. The fact that it's intermittent makes me think it's not internally engine-based either. I do wonder if maybe something is physically knocking against the firewall.

*Note -- this is a terrible time for this noise to pop up. Weeks away from listing this truck for sale.

 

Not really... Last time I had it at the stealership, they just zip tied a couple wires for me and told me that was the problem. Obviously that was not it so I had the head technician jump in my truck and took him for a drive. He goes "Yep, that's piston slap. All of our vehicles have it." And that was the end of it. Nothing about a fix or anything. He basically said there wasn't one and to not worry about it lol. This was over a year ago and the noise hasn't really gotten any worse or better.


So that's basically where im at... Hard to say for sure if it piston slap or not. I'm not about to start ripping apart the engine or pay the idiots at my local dealership to do it. I do know that it only does it when its below 0°C. It only happens when idling while in gear and gets a bit louder as i accelerate untill about 2000 RPM. If i put it neutral and rev it up to redline for a second, it goes away completely for the rest of the drive until i shut the engine off and let it cool down. However, the noise never goes away from just driving regardless of how warm the engine gets. Which, from what i understand, is not very characteristic of piston slap...

My next step may be to talk directly to Toyota Canada and see if they will do anything for me. I don't care so much about the noise (i'm planning to drive this truck into the ground) as I am about it turning into a bigger problem down the road.

 

I’m just assuming at this point that it’s transmission related. Lots of YouTube vids of different cars all making the same exact sound, and it’s usually a cracked flex plate or loose torque converter bolts. I was planning to sell this truck this summer, so I’m pissed.

 

My 09 Tacoma jus started doing this last night after I drove it hard on the highway. Hope I can get this noise to stop.

 

Saskabush said:

“ I do know that it only does it when its below 0°C. It only happens when idling while in gear and gets a bit louder as i accelerate untill about 2000 RPM. If i put it neutral and rev it up to redline for a second, it goes away completely for the rest of the drive until i shut the engine off and let it cool down. However, the noise never goes away from just driving regardless of how warm the engine gets.”



Yup its that time of year again. This time every year same complaint of knocking noise when its gets cold. Since I fixed my intake snorkel have yet to have it return and I had it for about 6 years before I found the fix here on TW. Im telling you folks, listen to the clip on utube of the sound... and disconnect that intake snorkel for a couple of days or weeks and I more than guarantee you it is the source of the noise. Plenty of others have verified they too had the same complaint with the same remedy.

My sound clip on utube. This is backing out of garage and going uphill on driveway.
https://m.youtube.com/watch?v=Xf6eA5kxe2k

 

Sakabush - did you ever find out what it is?