[FRSBRZGT86FAN]

Originally Posted by swarb

Seriously don't leave it on.
Any smoke when it happened?
Do you have a flex fuel kit?
How reliable is your fuel?
Did you put the wrong fuel in? Are you 100% sure?
Do you have any thing to read from the ecu? fuel trims etc?
Did you immediately make a pass after fueling?
Check your oil.
If you think it is the fuel, drain it from the tank and refill and hope the damage hasn't already been done.

Originally Posted by elchote

Hello guys, have this nasty engine noise that I need help diagnosing. Hope it's not the awfulness I'm imagining. Happened on a fresh tank of E85, at about 6500 rpm on second gear.

Mod list:
Borla UEL headers
Nameless hi flow cat uppipe
Isis catback
K&N drop in filter
Moto east E85 tune

Originally Posted by elchote

Could it be a manifold leak? Header has been rattling for the past couple days

Originally Posted by Apoc

Sounds like a hole in your exhaust.

Originally Posted by elchote

Yeah, it was a cold start, that's why you hear the noise go away when the idle dips. Was trying to smell for the exhaust but didn't smell it as too obvious, possible it was there though. When I first installed my Borla, I had a nasty rattle/resonance from the flexible couplings. I covered them up with exhaust wrap which helped a lot with the rattle. It could be that they finally cracked.

Sounds alot like a manifold exhaust leak to me as well, as you increase revs the sound becomes faster and more prominent?