Knocking at idle

I have a 2012 Toyota tundra crew max with high mileage. About 30 seconds after I start I hear a knocking coming from the engine. Listen to the video and let me know what you think please.

 

Welcome from NY.
There's no video link.

 

Hard to tell. How's the water pump? Could be a bad bearing.

 

From here in Hoover Alabama that sounds like the water pump.

 

Tundras have super aggressive anti-knock, it would immediately pull timing if there was noticeable knock and throw a code if you could actually hear it.

Thus I agree with above posts its likely something else.

 

Does the system work on rod knock?? Lolz

.... I would also start inspecting rotating accessories on the front of the motor before assuming the worst. Idler pulley, tensioner, WP (as mentioned)

 

It wouldn’t be traditional rod knock due to being an overhead valve motor vs a push rod motor. But I agree there’s a bunch of things that can make a similar noise as discussed in the thread for sure (timing chain tensioner, etc.).

 

Sounds like a bad bearing in one of your accessories. Water pump, idler, AC, alternator....... Pull the belt and spin them all.

That does not sound like a rod knock or a timing chain... But then the quality of sound on the video is not all that good.

 

TBH it does sound like the water pump.. That's kinda how mine sounded, until it exploded in front of my house of all places. It was also leaking, so it was already warning me. I would also do as mentioned above, remove belt and turn all pulleys. Make sure you replace that belt tensioner and the idler pulley, it will be much quieter after.

 

You guys were right… It was the water pump!!

Thanks for all your help… This forum is definitely very helpful.