car way to loud at 4000 rpm

[805eclipse]

i just got my head rebuilt and its all good now but when i give it some gas and and it hits 4000 rpm it all the sudden gets way loud and the tone changes although it didnt do this before.. any ideas why it would get way loud at 4k?

 

[LiquidOC]

maybe that's when your vtec kicks in, yo!

seriously, i'd check for exhaust leaks or maybe your headers weren't reinstalled correctly or something.

 

[unior]

i just got my head rebuilt and its all good now but when i give it some gas and and it hits 4000 rpm it all the sudden gets way loud and the tone changes although it didnt do this before.. any ideas why it would get way loud at 4k?

does the noise depend on boost level or simply rpm?

whats it sound like if you just give it 1/4 throttle and let it rev past 4k

 

[805eclipse]

yeah i tried that i would stay in first gear and just give it gas slowly till it reached 4000 rpm and then it made the noise i have no clue what it is

 

[805eclipse]

i also did just install a evo 3 exhaust manifold

 

[96TSi_Chris]

My guess is an exhaust leak. Start the car up in the morning and see if you can pin point and smoke coming from under the car or pop the hood and listen near the manifold. If its near the manifold, sometimes you can hear a light ticking. Ive got an exhaust leak right at the cat-back and downpipe connection point and you can hear it getting louder at WOT b/c of it.

 

[blackGSX2g]

do you feel any power difference when the engine changes tone? When an engine retards timing, it changes the tone alot...just a possiblilty.

 

[805eclipse]

i will check my exhaust and look for leaks but as for power loss i dont really feel anything