# SLP Bobcat Package - ticking noise (headers?)



## nickdz (Jun 30, 2007)

I recently bought an 06 GTO with the Bobcat 455 package installed. The exhaust sounds great, but there seems to quite a bit more "ticking" than I would have expected (at idle, it almost sounds like a sewing machine).

Could this be due to the long tube headers? 

The reason I ask, is that the ticking noise appears to be coming from the headers (I used my stethoscope). My thought is that maybe the design of the headers change the acoustics of the engine and hopefully this noise is normal.

For anyone who has owned a Harley Davidson or Buell motorcycle, the noise I am refering to is "normal" for those bikes.


Thanks in advance,
Nick


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## GM4life (Mar 18, 2007)

Humm the ticking can be valvetrain, injectors, is normal unless really loud then you have other issues like a lifter or bad injector or an exhaust leak. And on the other hand you can be right about the longtube headers changing the acoustics.


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## BLACK05GTO (Feb 6, 2005)

As mentioned, unless it gets louder its most likey just increased noise because of the headers.

My car made lots of different sounds after getting Kook's 1 7/8 long tubes put on. Now I don't even notice it. But at first it was a little weird sounding.


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## nickdz (Jun 30, 2007)

Thanks for confirming... it seems that this is normal when long tube headers are installed. 

Mike_V (has same exhaust) got back to me and said he got the sewing machine effect when his exhaust was installed also.

I think it gets back to the acoustics thing.


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## Good 2 go (Sep 7, 2005)

The LT's seem to act as a speaker for the combustion events of the power stroke. If you give her the spurs, you'll hear it intensify, 'specially with the windows down......  I actually thought I had an exhaust leak at first!


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## Red Bearded Goat (Mar 19, 2007)

Don't forget the SLP BC455 package includes a modification of the rockers with the install of longer arms. You should have the valve lash checked to rule out mis-adjustment before assuming its due to having LT headers.


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## GM4life (Mar 18, 2007)

Red Bearded Goat said:


> Don't forget the SLP BC455 package includes a modification of the rockers with the install of longer arms. You should have the valve lash checked to rule out mis-adjustment before assuming its due to having LT headers.


No lash adjustment on a LSx motor.


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## PEARL JAM (Sep 6, 2005)

What you are hearing is your exhaust valves slamming shut. It's more audible with a thin, header pipe bolted to the head than the thick, cast iron manifold you removed.


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## Red Bearded Goat (Mar 19, 2007)

gm4life said:


> No lash adjustment on a LSx motor.


Hydraulic lifters no tappet adjustment? I'm used to working on large diesel engines, never worked on an LSx so thanks for correcting my mistaken advise. Ditto to Pearl Jam!

Red.


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## GM4life (Mar 18, 2007)

Red Bearded Goat said:


> Hydraulic lifters no tappet adjustment? I'm used to working on large diesel engines, never worked on an LSx so thanks for correcting my mistaken advise. Ditto to Pearl Jam!
> 
> Red.


I know what you mean, I worked on SBC and Mark IV BBC, and diesel engines as well. But I think you can get adjustable rockers for the LSx motor.


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