What's this sound?

[OddJob]

Makes a chittering sound after startup. I always warm up the car before taking off, sound seems to subside sometime thereafter.

This was recorded after the car had been completely warmed up, then sitting (turned off) for 30 mins or so.

 

[jaffaz32]

sounds like something maybe sticking...

Ruled out throttle body butterfly as it happens just after it closes
Perhaps vvis butterflies? just a guess.

it's louder with a higher rev!

 

[DDozier]

Makes a chittering sound after startup. I always warm up the car before taking off, sound seems to subside sometime thereafter.

This was recorded after the car had been completely warmed up, then sitting (turned off) for 30 mins or so.

I would guess an idler pulley or timing belt tensioner. With either of these things the sounds would be coming form the passenger side of the engine compartment. Could also be an issue with the AC compressor or its tensioner, this would also be on the passenger side of the car and louder under the car than on top.

Dave

 

[OddJob]

Thanks. BTW, the crankcase breather tank in the video gives 10-15 hp increase, I was told.

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[DDozier]

Thanks. BTW, the crankcase breather tank in the video gives 10-15 hp increase, I was told.

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I have a sticker that I can sell you that will give you 30HP.

Dave

 

[OddJob]

LMAO. I didn't say I believed it.

 

[SuperSonic]

Dave, can I get 2 stickers lol. On the topic of sounds, any idea after I drive the car it makes a....I guess whin evaporation sound when it sits. If I remove the gas cap it goes away and lots of pressure is released. But it build more pressure an hour later until I release the cap. Did I pinch a breather valve in the tank?

 

[ENT]

x2 for idler pulley.