So the other day my friend wanted to see what my car could do, so I punched it and at WOT i heard a very odd noise. Like rattling, raspiness/scratching coming from what seemed to be engine/throttle bodies. Thats the first time ive heard that noise. Only the 2nd time ive WOT'd it. Well tonight, again at WOT, i heard the noise. Any ideas? Intakes? Cold weather?

 

Pinging, maybe due to crappy winter gas

 

could it be due to the intakes? causing me to run lean? it has been in the single digits, temperature-wise, here for a couple days now.

 

When it shifted, or while approaching redline? During shift is a known problem, haven't heard of anyone having the problem between shifts.

 

approaching redline, at higher rpms. it doesnt seem shift related.

 

A new problem, or has it been ongoing?

 

sure sounds like you're describing pinging.

 

so is it 1. intake problem, 2. cold weather issue 3. combo of both

like i said, ive only WOT'd it a total of 3 times. I dont remember hearing any noise the first time and that was with stock intakes at normal temps.

 

Could be a batch of bad winter gas too, as they change the formula during winter vs summer.

What octane gas are you using now? (91, 92, 93?)
Do you have access to 100 octane around there?
If you can get 100, pump in enough to raise the octane to 94'ish and see what happens.

 

i always use 93octane fuel...no 100octane around here

 

exact issue i had b4 . . i got rid of my intakes , put stock back in . . then WOoooolaa . . problem gone !!

i was running R2c BTW !! Lean as well !!!

 

so you were pinging and running lean in warm temperatures too?

any A/F numbers?

 

I experience the same weird noise at WOT with my r2c intakes. also others on g37 board

 

so the only 3 guys to have that issue use R2C intakes. Stick the stock intake back in and see what happens...

 

Sounds like pinging to me as well. This can be caused by excess moisture in the gas tank when the weather get cold. Note that the moisture usually comes from water condesing inside the underground storage tanks at the gas station and then transfered to your cars tank via the gas pump.