3.4 Tacoma engine rattle at 3,000rpms

3.4 Tacoma manual tranny makes a loudisb rattle in engine at around 3k rpms -4500 then clears up. Every gear even neutral. Have tried higher octane gas, didn’t help, and recently changed all spark plugs. It’s not a knock sound more of a rattle or shutter and I have no check engine lights.
Truck still has plenty of power as well. 189k on odo with oil changes regularly.

 

Is it possible that you have an exhaust heat shield that has come loose and rattles at those rpms (frequency)?

 

I checked, they’re attached and fine. I popped the hood and ravved engine up and sounds like it’s coming from the valve cover gaskets area

 

Is there a heat shield behind the engine in between the cab? That’s where it sounds like it’s coming from

 

got the same rattle here at 2.1k rpms briefly in all gears, i rarely take mine over 3k unless in 5th gear so not sure if it still happens up there or not, the engine noise would probablly muffle it idk
just popped up last year!
sounds like behind the glovebox for you?
also, mine is MUCH worse when the A/C has been on and then when i turn it (A/C) off getting off of the freeway, so this is a humid spring/summer issue for me
i.e., no problems that i can detect so far during the recent winter months

i wonder if its a driveshaft problem or mount that is vibrating
its gremlinish if nothing else

 

i think so, sorta U shaped?
i have not made it that far to self-diagnose yet

 

I don’t think it’s a drive shaft problem since it happenes in neutral as well. I’ll check heat shields

 

i cannot recall if i tested in neutral, but i definitely will to check


the thing that gets me is why the A/C (after shutting off) makes it so much louder!

 

Are all of you exhaust connections good? I had a bolt fall out where the collector bolts to the down pipe and it made a pretty nasty rattle at 3k RPM or so

 

I’ll give a check thanks

 

https://youtu.be/0ZZWGeRh7Es
heres the video. Not sure what it is

 

my vibe can get much worse than that

 

It’s more of a rattle shutter sound. No vibration in cab or anything

 

i hate to have to pork over the $100+ diagnosis fee to mechanic to figure mine out
especially if it does not do it under idle like yours does

 

... sounds expensive ...

 

Sounds like a heat shield to me. Maybe it got bent a little bit and is rubbing on something even with the bolts being tight.

 

Not sure. Checked u see and didn’t really see much play

 

Heat shield x2

 

the heat shield for the catalytic convetor has been an issue for me for a while. On my 96 there is a single stud that is welded to the body that a metal push washer is used to hold it in place, after 20+ years, the hole wallows out and the shield just rattles on it.

 

So look at the cat converter ? Hope this is it! Thanks for the input. Nervous it’s inner engine