Engine sound at the rear?

[johnnyballs180]

S13 SR20DET

i searched all over NICO and google didn't find exactly what i'm looking for. i hear the sound best inside the car, and just a little bit from the engine bay, but that's probably because there's so many other sounds. i've decided it's not the chain, nor the injectors, or the heat shield, and not the belts. also, it's only been colder here (only about 65*) for about a month, so i'm riding with the windows up. i don't know if this sound's always been there (had the car since spring) and i just haven't noticed it, or if it's new.. but i've only really noticed recently.

it's hard to describe what it is, but i can tell you it isn't a tick or knock or squeek.. it's closer to a rattle, but not like a marble in a can. it's a constant sound at all rpms, and seems to quicken with rpms. it gets a tad louder, but then i hear my exhaust soon afterwards which makes everything inaudible.. otherwise, i can barely hear it unless my head's right up on the dash.

oil is fresh and the level is fine, but i don't know the pressure.. flywheel/pressure plate maybe? i don't know what kind of [bad] sounds come from the valvetrain or bottom end either.

[johnnyballs180]

bump

i don't have much of a clue what the sound could be.. it's hard to isolate. the only thing i can think of is to just.. have at it and trial and error? i'm pretty sure it's not the flywheel/clutch; the sound doesn't change between gears or in neutral. help help help

[theother1wstolen]

exhaust bolt loose somewhere?

[moulton712]

exhaust leak?

[johnnyballs180]

no, not an exhaust leak or loose bolt.. i even thought of those being possibilities.

to be honest, at this point, i'm just gonna drive it until a real problem reveals itself, and i'll go from there. chances are i'm over-thinking it. i'm kind of a worry wart when it comes to my car.. but what can i expect? it's 15 years old!

[Ladreik]

Do you have the stock exhaust? The muffler could be comming apart in the inside or the rubber on a hanger could be broke... making your muffler rub on the hanger...

[johnnyballs180]

no, not stock. the exhaust i had before this one wasn't stock either, but it actually fell apart. i kept hearing squeeking sounds that came from the muffler for a long time, and then during my turbo swap when i removed the entire exhaust, where the piping meets the muffler, it fell apart in two.

i did check the exhaust though, and i'm actually surprised how good of shape it's in!

i'm almost confident it's something in the engine. since i only hear it inside the car or underneath, i'm considering rods or pistons. it's almost a spooling sound.. as rpms increase, so does the sound. the car's seeing more boost than it ever has in the past (but nothing too unreasonable..), so maybe it's a bad side effect.

keep throwing the suggestions out there though!! nothing has broken on my car for a while.. so maybe it's saving up for a major break! hahaha

[Ladreik]

Could you possibly record the problem in a video, place it on You tube and link it on this forum? I bet we could help alot more that way.

[johnnyballs180]

sure. there's a little bit of junk in the audio so it might not be that clear. i'll post it tonight.

[lil_ben_20200]

is it in nutral too or jus when drivng bc if it is jus when driving proly drive shaft weight taping exaust

[johnnyballs180]

always always, gear or neutral, slower or faster.

basically, it sounds like the engine doing it's thing.. which sounds stupid, i know, but what worried me was that i could hear it so well. you know, through the firewall even.