Odd vibration resonence around 4k rpms
 

ok guys for a while ive been getting a pretty nasty vibration rattle resonance sound under load around 4k rpms.

It seems exhaust related almost as if its rubbing on some thing but it isnt. there appears to be plenty of clearance around the system. Im running a pacesetter header to a test pipe to a borla y-pipe and borla mufflers.

The noise is definatly coming from the rear and its almost 100% audio I dont feel much of anything.

Im kind of at a loss with this one. I dont think its the exhaust system as it only does it under load; but I cant rule it out.

Any Ideas?

Diff noise man thats what it sounds like. Does it change on accel or decel or is it steady?

I'd guess that it's exactly what you think...exhaust system resonating.
The thin wall headers and lack of cats has created sympathetic vibration in the system that is most apparent at 4k rpm.
An easy test would be to replace the test pipe with a cat and see if the vibration/resonance changed or disappeared.

I realize you said under load, but can you re-create the resonance even briefly while parked? If so you could put the car on a lift and have an assistant grip the exhaust with a mitt or welding glove to check for vibration or harmonics.

Even if not, you might be able to kill the vibe by adding an exhaust hanger to the longest unsupported section of the exhaust. Cheap easy try.

Good Luck.

I feel stupid. It was the exhaust reasonance vibrating the loose spare tire. removed the tire sound is gone...lol my bad

Thats funny! I had a 2003 Honda Accord with a nasty vibration at about 6500rpm.

I took it in for warranty and they could not reproduce it. I then drove it with the tech to demo the buzz. They found the buzz and told me about it. I had my doubts...














It was the plastic cover on the owners manual in the glove box! Solved by placing my windshield scraper on top of the manual rather than underneath the manual. :facepalm:

bump this shit..

this just started happening to me last night.. it definitely isnt anything like any of what ^^ these guys said.. it is definitely coming from the very back of the exhaust.. i have a straight pipe to a recing beat tip. the resonence sounds like its coming from right before the tip. but i'm not sure HELP

Spare tire?