Need Help
 

I have this problem where my 8 makes this strange noise at 7k. When I'm driving, the car sounds smooth, but when I hit 7k it sounds like it hits cut off or misfire but still goes up to 9k. Can anyone help?

Do you have any Aftermarket intake or anything? Sounds like its getting a shortage of air. . . . .

How many miles? Could it be a clogged cat?

Pull the hairball out of its throat and you will be all set haha. . . Yea we deff need some more information about your car to help ya out :)

I have an 04 6MT with Mishimoto Carbon Fiber intake, Turbo XS Catless midpipe, GReddy SP2 cat back, and 85,000 miles

Ok so heres an update. I just put my stock intake back on and the engine smoothed out alittle bit. My car still has that rough sound when I hit 7k but it's less noticeable than before and it doesn't happen all the time anymore. Some more history on my car, spark plugs have about 20k on them, plug wires I have not changed since I got the car last year, and the same goes for the coils. any more help would be great.

you've tried two ways of explaining what it sounds like. you've said it's a rough sound. and you've said it sounds as though the fuel is being cut even though that isn't happening.

neither of these will help anyone tell you what's wrong.

and you haven't reported any power loss.

try again.

for those who are willing to help me
Problem: My car makes this weird sound at 7k - 8500 rpm. It sounds like the car hits cutoff. During this sound, the tachometer doesnt go back and forth like when it hits actual cutoff, the needle instead moves normally and so far I have not experienced any power loss. This sound happens both when the car is moving and when the car is sitting still. I also found out that when I floor it this sound doesnt happen but if i go up to 7k and higher without flooring it does happen. I already know that its not the spark plugs, wires or coils because I have already tested them. My car is an 04 6MT with 85k miles, GReddy catback, Turbo xs catless midpipe, and dewalled stock intake.

Does it sound like a bunch of sand moving around inside a can?

it doesnt sound like sand in a can, it sounds like cutoff

Got that noise fixed. I put my mishimoto intake back on with a freshly cleaned filter, cleaned the MAF sensor, reset the ecu, did the brake trick and the odometer button trick. I let the car idle for about 15 minutes thne revved it a couple times and the sound didnt happen. Then i drove it to make sure it was really gone, but it was still there. Then i did a top three gears redline run. When I hit redline in first, I shifted into second and there was this big backfire. The backfire was not only loud, it was so storng that I felt it and there was a big flash in my rear view mirror. This also happened when I shifted from second to third. After that I did another run and the cuttoff sound was completely gone. I'm guessing that the problem was carbon build up but i didnt see anything abnormal on the spark plugs when I checked them. Going to seafoam it later to make sure all carbon is gone.