I added cams/springs/retainers around 2k miles ago. Dyno tuned it and everything. ever since i picked up the car from the shop its been having this sound in the video everytime the rpm's would reach 4.5k-5k. A buzzing/vibrating sound. It is more present when at a stop free revving. heres the videos. I included 3 videos. the incar one is tough to hear but it is present when it decels from 5k. Idk the sound may be normal from adding cams/springs/retainers but idk. thanks for the help.

 

btw the car drive's fine its just the sound.

 

did you have to redo your timing when you installed the cams? if you did i think you might have the same problem as me. I'm gonna go fix it once KevinD has time for me. he's a very reputable tuner in dallas so ill keep you posted when i get to meet him.

mine starts to vibrate like crazy when it starts to reach 4k rpm.

 

Odd, I too started to have this vibration after I put in aftermarket valve springs. I had a tubular manifold put in as well though so I thought maybe it was the exhaust resonance from that.

 

maybe it is the springs/retainers ? IDK..is it the same exact sound in the video ?

 

what brand springs/retainers do you have ?

 

mine is doing the same thing but mine is stock with ams Turbo-Back Exhaust and ams race fmic

 

maybe an exhaust component is rubbing against something ? hopefully its not too major.

 

I had my transmission replaced at the dealer. To make an extremely long story short, the dealer did a little digging and found that the counterbalance shaft in my engine had been removed. They said that some collar on the front of the driveshaft (my guess is where the output shaft connects to the ujoint somewhere) was vibrating. My car has a really loud metallic rattle in between about 4k-4.75k. I havn't put it in the air to verify if thats where its coming from, but just a thought...

 

mine rattles at idle, but it is the mounting bracket that is holding the driveshaft tapping my exhaust. i have to grind one of the bolts down. annoying rattles bother me so much!

 

so did you find out what the noise was ?

 

Could be the oil pump 180 degree's off which causes the engine to vibrate at a specific RPM. Pull your lower cover and set the timing and see where it lines up.

 

if you don't have ballanceshaft than what ?

 

No balance shafts? Balance shafts are intended to rid the engine of vibration. So, I'd say, in your case, it is normal.

 

but the noise wasnt there before for the last 7k, until recently it making weird sound like loose chain when free reeving past 3.5k