Flutter or Rattle Noise

Have an 09 4.0lt auto and have been dealing with an annoying rattle or flutter noise. Only happens in cold weather on intial startup. Noise is heard in cab on driver side down by pedals. Cannot hear the noise in engine bay or under vehicle.

If started in garage its fine...back out of garage into the cold it acts up. Does it most times if started outside when cold. Goes away in 5-10 minutes after it warms up. Audio attached actually sounds worse than it is. Definitely not coming from engine as it doesnt match the rpms. In audio attached rpms are around 1500 till I put in gear and drive up hill on driveway.

Have checked exhaust and everything in engine bay and cannot figure this out. Have owned truck since new and it started doing this in its first year. Was so intermittent then figured it wasnt worth bringing to the attention of the dealer. Now that its aged it seems to be more frequent.
https://www.youtube.com/watch?v=Xf6eA5kxe2k&sns=em

 

The video would be helpful, but you'll probably want to upload to YouTube or some similar hosting site then bring the shareable link here and post it.

 

Bump

 

I had a noise similar to this one time and it turned out to be the foam gasket where the air intake hose hits the fender. It would rattle like crazy until it warmed up. I ended up tearing the gasket off and replacing it with weatherstipping.

You should be able to replicate (if that's what it is) by shaking the hose near the fender.

 

I hope its something like what he said ^ because what I'm honing in on sounds like it's the engine (that said, online video diagnosis's are always just a best wild GUESS thing).

I know you say it's not coming from the engine, but I hear a rotational sound that does sound like it matches RPM (though slightly behind the throttle application). Have you checked valve clearance lately? Does it do it in the cold even after a fresh oil change? Maybe I'm just focusing in on an engine noise that is amplified by the video and completely barking up the wrong tree.

 

I always thought it might be an exhaust leak but have found no evidence of such. I am almost certain its not coming from the valve train or engine. Cant hear anything unusual in engine bay. In video engine is at high idle around 1500 rpms or so until I put it in gear to drive uphill, and noise is no where near rpm speed...even at half speed indictive of upper valve train speeds.

I will remove air cleaner snorkel to fender and see what that does. Ive heard of that before as a possible solution. Still sounds like its in the driver side exhaust.

 

Good luck. Forgot to add that my rattle sounded like it was coming from under the drivers seat so I originally thought it was the heat shield or my exhaust. I even bought an entirely new exhaust only for it to not fix it. Then someone on here told me to check the air hose sure enough, that's what it was.

Edit: Maybe this will help https://www.tacomaworld.com/threads/cant-find-this-rattling.82181/#post-9109497

 

Give this man a cigar!!! Took off intake hose and worked like a charm. No noise at all. Should have done it years ago when I first read about it. Cant believe a rattle on the right fender can travel to the interior by the pedals.
Also found no evidence of the gasket failing or contact of the intake to the fender. Strange!!

 

Glad it worked for you!

 

Sweet, glad you got it figured out and it wasn't something serious! Thanks for following up too.