Ok im having a head scratching moment I have a full SS system racing beat header , borla catback and a racing beat race pipe/ bhr high flow cat but im getting a weird buzzing rattle noise its not that prominent with the bhr pipe but very noticeable with the RB decat (unresonated) ive checked underneath there is nothing touch any metal and ive reseated twice now so what could it be its almost like im getting transference from the engine cos the rattle/buzz can be heard all the way down I dont know where to look.

 

if it is distinctly metal on metal, and the BHR muffles it but does not remove it, then it should be upstream of the BHR resonator and inside the exhaust stream, so likely the header.

If a "rasp" is closer to the noise you are hearing, then that is almost assuredly the header, as the engine is naturally raspy, and the BHR resonator is the only one that effectively kills the rasp for an OEM header and whatever catback. The RB header might be making it rasp enough that the BHR can't muffle it totally.

 

Check the bracket from the header to the transmission.......Have seen a couple of those fail and cause a rattle...and they look normal with a quick look

 

I've just had the header fitted it replaced a cheap header which was causing real issues including a much louder rattle

 

il record it tomorrow and post the noise

 

ok didnt have time to record the rattle had to refit my bhr pipe ready for a track day but the rattle is still there but less noisy so its coming from the header or beyond im gonna get under and check the header bolts but I had the same rattle with the other ss header I had that gor replace so could there be an engine issue causing the rattle

 

Here is the clip it sounds worse then it is but you get the idea

 

I was getting the same rattle, worse when i put it in reverse, none of my pipes were touching metal either. Motor mounts was the culprit. I just put in those new mounts from rx8 performance.

 

I did wonder if it could be that

 

Well finally changed my mounts but still have the rattle so tomorrow il go out and remove the Borla catback and refit it or maybe refit my oem backbox depends on weather this is just getting a bit frustrating people are now commenting on how I need a new exhaust cos mine sounds like a bag of spanners

 

Verify that you have no metal-on-metal scrubbing near your exhaust hangers.

I had some length fitment issues with a midpipe installed and the rubber exhaust hanger..grommet? Whatever the rubber piece is that you attach your exhaust hangars to was being squished and the hanger was tapping onto the brace on the car. Bending the protruding part of the brace out of the way fixed this problem. This was on the farthest hangar on the passenger side at the back of the car(under the trunk). Check these to see that the rubber mounts aren't wearing out and getting too squishy and allowing the exhaust hangers to tap in places they shouldn't be.

 

Does the rattling only happen when the car is cold?

 

Il check again but i think there all clear.

And the rattle is worse when cold and eases of a bit when hot but that's driven for an hour hot not 10 minutes warm

 

Ok removed my borla but the rattle is still there and there is zero contact anywhere so it's gotta be engine end .
Someone has said maybe ssv and I have been concerned with it as it seems chatter from time to time.

 

Managed to check my spark plugs and leads today all fine and the SSV doesnt seem to be moving or ticking at all so im lost at where the noise is coming from.

 

Still rattling argh!!!!!!!!!

 

Ever get a chance to swap your header back to OEM?

 

Unfortunately I didn't keep that header which was dumb but then surely it can't be the aftermarket headers I mean I run an identical setup to a mate and his is fine.

 

I have had this same rattle for a while myself. Same symptoms as well, including the changing as things get hot. If I put my foot on one of the exhaust tips it stops, so its a vibration of some kind, just dont know were.

 

Will have to try the boot method and see if it changes

 

Greg have you tried using better bolts on the manifold's end? I had it happen to a friend once and that's what caused the rattle since the flanges weren't mated tight enough.

 

you know, thats a good point, had not thought of that

 

bolts to the engine or to the midpipe?

 

I'd start with the midpipe side of the headers.

 

Fitted various forms of bolts there oem and none with various washers and I can tell you it's tight will have to see if I can get a good look at the header to engine bolts.