i recently bought a rb25 swapped s13. it was probably about 2 or 3 months ago and i LOVE the car. its stock except for top mount precision turbo, FMIC, greddy intake, exhaust and APexi power fc ecu.
ok now to the problem im having. when i start the car cold, it makes this go cart sounding noise when i rev it. i cant hear it at idle, only when its being revved, but it sounds like its coming from the exhaust manifold/turbo area. so i thought the obvious, its probably an exhaust leak. i ended up replacing all the easy stuff first: wastegate to manifold gasket, turbo to manifold gasket, turbo to downpipe gasket. still no luck. ugh. its got to be the head to manifold gasket right ? i replaced that today, nope, still making the sound
. keep in mind the noise always goes away after driving for about 5-10 minutes so i thought it had to be one of those metal gaskets not sealing properly untill it gets hot and expands. but now im stuck. this is my first long block so im still learning but guys please. i was told it could be a lifter, but ive heard those before and its not making that kind of sound. just incase it matters im running t6 rotella engine oil. this is so annyoing! any help is appreciated! thanks!