Anyone want to make an educated guess on this noise? Video inside.

[hearno]

**Updated** Anyone want to make an educated guess on this noise? Video inside.

I really only hear it on cold starts. Distinct, rhythmic, clunking noise. I thought maybe piston slap? Maybe. Not so sure now. 2007 V8, 129k miles. Any insight would be appreciated.

https://www.youtube.com/watch?v=mwLB0ct9vkI

 

[Morphyne]

i saw you weren't moving. but were you in gear? whatever it was, doesn't sound good.

 

[hearno]

In park. No drivability issues. Never there on warm starts.

 

[hearno]

Gonna bump this up as I think I've narrowed it down. I believe it's the manifold leak issue. Only on cold starts, goes away after a few minutes, seems to pulse with exhaust.

 

[keakar]

cant hear enough to determine much from the video, could be something with exhaust maybe, check donut gaskets and flange bolts are tight, check heat shielding.

things that only make noise when cold can be cold lose metal parts in the exhaust or leaks that will seal or stop being loose when it warms up and metal swells.

you also need to go outside and follow the noise, open the hood, see if its coming from up top or down under, left side or right side

 

[duffdog]

Piston slap? Every high mileage 2uz v8 does that until it warms up. People stop making posts about it during the summer because its warmer out and then make frantic posts in the winter when its cold thinking that their engine is about to explode.

So, on the sides of all the 2uz pistons there is a black coating that wears off. Its like a thick paint. When it wears off, the pistons make noise until the oil heats up.

 

[Antoddio]

Sounds like piston slap but tough to tell from that vid. If it goes away I'd ignore it. Mine has made noise for the last 10 years on cold start.


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[AuSeeker]

Piston slap? Every high mileage 2uz v8 does that until it warms up. People stop making posts about it during the summer because its warmer out and then make frantic posts in the winter when its cold thinking that their engine is about to explode.

So, on the sides of all the 2uz pistons there is a black coating that wears off. Its like a thick paint. When it wears off, the pistons make noise until the oil heats up.

I have a 2004 V8 and it has way more miles on it than the OP has and it has never had any noise at all at any time, cold or not, so not all V8s do that.

Maybe my 4Runner V8 is the exception, or maybe I'm just lucky, if so it's about time I got lucky in my life!!!

 

[Antoddio]

I have a 2004 V8 and it has way more miles on it than the OP has and it has never had any noise at all at any time, cold or not, so not all V8s do that.

Maybe my 4Runner V8 is the exception, or maybe I'm just lucky, if so it's about time I got lucky in my life!!!

How's your hearing? Lol.


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[jonesmw10]

My GX does it too. Goes away after it warms up.

 

[AuSeeker]

How's your hearing? Lol.


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My hearing is excellent, I heard you typing that question!!!

 

[Antoddio]

My hearing is excellent, I heard you typing that question!!!

Haha, oh my!

Part of it is your area. These sounds go away after about 30 seconds of heating up or less. So if you are in the deep south, you stay pretty warm.

Next time you are in 30 or 40 degree weather, start your engine and immediately put it in drive with your foot on the brake (window cracked or down)...it will sound pretty loud with what I think is the exhaust leak. Then immediately start to mildly accelerate away and you will hear quite a knock from the engine, presumably piston slap. It all goes away in like 20 seconds. Mine's been doing it for 10 years.

If you don't hear either of those, you are either a liar or a lucky man!

 

[hearno]

I was able to get another video since it was kinda cold this weekend. Right around the 12 or 13 second mark, you can really hear it and it's gone by 16 or so.

https://www.youtube.com/watch?v=rhN0MFkhRGI

I'm just hoping someone can confirm that what I'm hearing is the manifold leak and not something else.

 

[Bob22222]

We've two 04 V8s. The 4Runner now at 197 k does it. But you can only hear it in gear in a garage or other "sound chamber" . I Started hearing it at about 170k. I'm not concerned. I would describe it as a clicking or tapping rather than knocking. The GX470 at 125k does not have the click. I have thought it could pollution control stuff, maybe?
I'm not sure but if The OP thinks it's a heavier knock do these engines ever experience sticky lifters? Has the engine oil ever gone an extended period without changing?

 

[AuSeeker]

We've two 04 V8s. The 4Runner now at 197 k does it. But you can only hear it in gear in a garage or other "sound chamber" . I Started hearing it at about 170k. I'm not concerned. I would describe it as a clicking or tapping rather than knocking. The GX470 at 125k does not have the click. I have thought it could pollution control stuff, maybe?
I'm not sure but if The OP thinks it's a heavier knock do these engines ever experience sticky lifters? Has the engine oil ever gone an extended period without changing?

There are no lifters in these V8 engines, they have overhead cams and the cam is in semi direct contact with the valves, there is a cup on top of the valve that the cam actually contacts.

 

[hearno]

We've two 04 V8s. The 4Runner now at 197 k does it. But you can only hear it in gear in a garage or other "sound chamber"

It definitely has to be quiet to hear it. Can you tell me if what you hear in your truck matches what you're hearing from mine?

 

[Bob22222]

There are no lifters in these V8 engines, they have overhead cams and the cam is in semi direct contact with the valves, there is a cup on top of the valve that the cam actually contacts.

I know, I just woke laughing at myself thinking of how stupid that was. Time warp? I don't have bats in my belfry, but I have had a stray dog on my new roof (I live in a earthberm house) and it's quite a distraction if that's an excuse. I don't drink so no excuse there. But this is Colorado....
Anyway, it does kind of sound to me like an oil not up to pressure issue but I really doubt that in these engines. Once, I offered elsewhere that's kind of like what a loose wrist sounded like on startup in the old days. But like that or piston slap is highly unlikely it would seem again in these engines.

 

[Bob22222]

It definitely has to be quiet to hear it. Can you tell me if what you hear in your truck matches what you're hearing from mine?

I can't play the sound file. But If is a light sound I wouldn't worry. Anything, serious (like a bearing knock heaven forbid) we would all likely know by now. And like Auseeker pointed out, no lifters means no valve noise associated with low oil pressure.

By the way, I know my issues is not related to lubricantion. The oil is always as clear when it comes out (5k) as when it goes in. I consider that amazing at this mileage.

 

[DeepSea88]

Does this only happen in the winter months? Since you're in VA I assume the idea of cold starts only could be contributing to the issue. Error on the side of caution and have it looked at. Worst case scenario is that you'll shell out a couple of clams to fix the issue before it gets to the point of no return. I'm sure you want that rig running as loooooong as possiblez. Hope all goes well!

Happy trails!

 

[RPC]

I have a 2008 V8 SR5 that has been making that sound for the last four of five years. Same story- does it when it's cold, stops when warm, seems to make the sound more consistently when I'm turning the steering wheel but could be my imigination.

Have taken it to three dealerships, some several times, to diagnose with no luck. Always couldn't duplicate, even once left it there overnight and went back in the AM to fire it up for the first time with a Mechanic standing there. I recorded it on my phone and played it for a few folks at the last dealership and no one could diagnose based on that.

Still have zero idea what it is, just hope it doesn't indicate something bad.

Shoot, I even posted this back in 2015 trying to get help diagnosing: http://www.toyota-4runner.org/4th-gen-t4rs/190966-what-sound.html