faint flutter at 25--..?

[tddvrrn]

so, i've been hunting rattles and creaks in my cabin lately. since i'm now driving with the radio off i can hear all sorts and i'm hearing something from the engine i am unsure of. if i go up to 2500-2750 and hold it gently there i will sometimes hear a fluttering, sort of like a faint sewing machine sound.

is this normal? in my last car, a 1.8t vw passat, i had a timing chain tensioner that was going and i had a sound that was maybe of the same type. it also sounds a bit like valve tapping.. or it could be just how the engine sounds..

any help is appreciated, but i always find it humorously futile to try and document noise diagnoses through the written word, so not too much is expected.

 

[SallySpeed3]

any mods?

 

[tddvrrn]

yes, poop on me for forgetting. i've only a pg sri, rmm, shifter bushings and that's it. i definitely can hear the turbo spool, and sometimes that has a flutter sound to it, but the one i'm trying to figure out is more of a mechanical sound, which is why i'm leaning toward timing/valve chain or valve movement...

SallySpeed3- i actually came across a post you had put up as i searched for this issue last night. mine isn't structurally mechanical, as yours seemed to be, but much quieter and within-the-engine sounding.