4.0 knocking?

I bought the truck a few months ago, it's a 2012 tacoma with the 4.0, had 145,000 miles, runs great. I change the oil every 5000 with full synthetic. It makes this sort of knocking/metal on metal sound only about 50-60% of the time when idling or at RPMs below 2000. When I rev it up or when accelerating I don't hear it. It seems to be worse when it's cold outside but not necessarily whether the engine is cold or not. I've read a lot about these 4.0s being noisy, can anyone who owns one confirm if theirs sounds the same?

https://youtube.com/shorts/Scl--xfjN3I?si=UgJYCNhDVom-TN3E

 

Sound like this one. They are noisy, mine is noisy don't worry about it.

 

OP sounds more like rod knock than the 2nd one. Check oil pressure? Maybe throw something thicker in there to see if it quiets down?

 

Do a used oil analysis

 

Blackstone Laboratories Blackstone Laboratories (blackstone-labs.com)

 

FWIW my '13 sounds the same. I especially notice it when I idle my fat ass up to a drive-through window; it seems to echo off the wall. I'm at 201,000 and the 4.0. From what I've gathered, the "Taco knock" is fairly well-known, but not widely accepted as the "Taco tick" though. I'd be a little more concerned if it mine stayed consistent with the increase in RPM but it doesn't. So until that happens, I'm going to just keep changing my oil at 5k and eating fast food.

 

You can't miss a rod knock. I don't think it's that but an oil analysis is a great tool to see if realy something is going bad. If there enough oil and changed frequenly i don't see why out of the blues a rod knock can start for no reason on these engine. Crack the oil pan under, if it's sludge town inside you will need to worry.

 

That sounds normal to me.
The fact that the sound is sometimes more prevalent than others, makes it even more “more normal” in my experience.

I does NOT sound like rod knock.

Don’t get worried. I think the truck is just fine.

 

The top end of the 1GR is ticky/rattly, and that's normal.

Can't really hear a rod knock in that vid (doesn’t necessarily mean it's not there) If you move your head around to locate it, rod knocks emanate from lower in the engine, and sound a little more "intentional" like hitting a hammer on metal. IME you hear (almost feel) rod knocks when the load changes, i.e. when you're just on or off the gas while driving.

How much do you know the history? Has a head gasket been replaced?

 

I have this noise on my 2014. 4.0L 104k with 5K synthetic oil and OEM filter changes since new. No oil use, smoking, etc. It's not rod knock. You'll know that sound when/if you hear it: hurts your ears to listen to it. To me it sounds like exhaust noise and coming from the down pipe and cat on my truck. The mechanical lifters don't help and add to the "symphony" of these engines. I don't hear it at all in the warm weather months.

 

FWIW, there are no lifters on the 1GR. 2 overhead cams on each bank (1 ea for intake & exhaust) directly open valves with only bucket shims in between.

It does make for a notoriously noisy valve train tho, but that’s a feature,not necessarily a flaw

 

I always used dino oil until it became hard to find locally and I switched to a synthetic blend. Engine is definitely noisier, especially for the first several miles after an oil change. How fresh oil makes an engine noisy is beyond me, but in my case, it's a fact. Maybe, just maybe, your full synthetic is causing at least some of what you hear. A different brand of oil might be quieter, or even a switch to a blend.

 

Thanks for all the replies. I'll probably do an oil analysis just to see what shows up if anything. It must just be normal but it honestly drives me crazy! Guess I'm just gonna have to get used to it.

 

Thank you for the clarification: never realized that.... It makes so much noise I just as*umed they were solid lifters.

 

Trucks fine. They all sound like that.

 

My first Tacoma trying to get used to the engine noises . Just sold my 2002 Tundra & having regrets ,only had 125K . Everyone says ignore it their loud & after pestering some unknowledgeable shops I'm reading these threads is helping . Still trying to find a good Tacoma shop around Spokane ,WA. if anyone can recommend. Tacoma World is a great source for info ! Thanks Y'all

 

My 1gr is noisy like shown in the thread when it's cold. Then after warming up, it's super smooth and quieter.

 

To me that's a combination of normal engine noises and an extra noisy serpentine belt system. I'd pull the belt off and check the idler and tensioner pulleys.

 

Good idea ,Thanks. I had it changed last year but I'm sure he never checked the idler & tensioner pulleys. Hard to find a through mechanic anymore , remember when they would go the extra mile & didn't have to be told plus they put the cheapest parts on & cry like a baby if you bring anything with you. I'm pushing 82 & can't crawl around in the new engine compartments ! ha ha

 

The difference (reduction) in engine noise when I swapped out the pulleys was pretty amazing, I could easily hear the injectors ticking again at idle, I hadn't noticed that sound for a long time. On mine there was a slight amount of play in the pulleys that I took off and I could feel the bearings in them were a little dry, they didn't roll with the slight drag a greased bearing has. They were definitely on their way out but outwardly they weren't critical yet, I could see where a mechanic not looking for worn pulleys might not catch it.