New 4Runner knock :/

[AntleredRuin]

Doubt it's anything related as its after the car warms up. However I'll check that

That's what I meant, more AC compressor than actual belt. Pull the belt and see. I meant replace/inspect the rest of the belts while you have them off.
I would think a belt would knock instantly, regardless of temp. Compressor knock isn't noticeable with the higher RPMs from a cold start. More noticeable after a few minutes when the idle RPMs lower.

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[thegipper]

Did you visually check the oil for any metal sparkles in it? When I had a rod bearing shit the bed on my grand prix (noticeable knock), I knew the motor was shot when I looked on the dipstick and saw little metal "sparkles" all over it.

It's a quick and easy check. If you see the sparkles, plan on getting a new motor. If you don't find any, keep checking the other things people have suggested.

 

[Brveagle]

I wonder if they were using thinner oil to flow better and cover up the knock. Red could also be transmission fluid which is an old trick to flush engines. Hope it's not as bad as it could be.

Correct me if i am wrong, but doesn't one put in thicker oil to cover up a rod knock? Thicker oil, higher oil pressure.

 

[Trojan4x4]

Did you visually check the oil for any metal sparkles in it? When I had a rod bearing shit the bed on my grand prix (noticeable knock), I knew the motor was shot when I looked on the dipstick and saw little metal "sparkles" all over it.

It's a quick and easy check. If you see the sparkles, plan on getting a new motor. If you don't find any, keep checking the other things people have suggested.

Changed the oil today, looked ok - although little thinner than I'd like,maybe a fuel problem.
Cut open the filter, however I didn't realize how many flakes I would produce while cutting it. FYI - those Mobil 1 filters are damn good built

I also recorded a video last night from inside the cab. Kept the car in gear and around 900rpm
https://youtu.be/wDpPRJua17g
The exhaust noise is NOT the exhaust

Going to check the AC compressor sometime soon per some suggestions

 

[baja1]

I don't hear anything.....

 

[Trojan4x4]

I don't hear anything.....

It sounds like an exhaust, except it's not. Only happens under load

 

[jgue467]

I don't hear anything.....

Me either, I mean I only hear some slight phone moment sounds, no engine running sounds..... I know I'm getting old but.... :cowboy:

 

[thegipper]

I didn't hear squat either. Perhaps a video under the hood would be better. I'm starting to really doubt that you have any kind of rod knock, my experience with it is you'll know for sure when you have rod knock.

Maybe it is just a bad pulley or something?

 

[mtbtim]

I heard it. Had to turn up the volume on my laptop all the way and then hold the laptop screen right near the side of my head. There's definitely a knock.

You already said you did the screwdriver method and determined it was coming from inside the engine so that rules out the AC compressor. My Subaru Outback developed a "Piston Slap" noise once it got up to around 250k. Piston slap was a common thing for those engines because the piston skirt was made shorter to improve gas mileage. I've never heard of our 3.4 v6 engines having this issue but that's what it sounds like to me.

I guess if you don't plan on taking it on long trips, I'd just drive it until it implodes. But, having that engine noise would be unsettling if you planned on driving far from home and the whole time you're praying the engine doesn't give out when you're in BFE.

Anyway, hope you figure out the cause of the noise.

 

[thegipper]

my 95 ZJ with the inline 6 4.0 were notorious for having piston slap. A guy I work with was a jeep mechanic for 17 years at a dealership. He said brand new 4.0 had piston slap. Customer would complain about it so they would put in a brand new engine under warranty. Unfortunately, the replacement engine had the exact same piston slap.

309k miles on my ZJ and she "knocked" every day of her life. I sold it to the husband of my wifes client, he still drives it and it still runs great.

Never heard of piston slap on the 3.4 but I've read some of the Toyota 4.7 V8's have piston slap.

Hopefully you can pin point exactly what is causing the knock, I wouldn't feel comfortable driving very far from home with a knock on this motor.