I get this clicking noise sometimes when I press down on the throttle say when shifting into second going at a regular cruising clip (click or sometimes click click)... it sometimes happens from a roll as well in 1st especially when I'm going up a slightly incline, but it also does it on level roads. I believe it's coming from the back-end area of the car. I have a 996 C4S lowered on PSS9s.

My indy says it might be slightly knocking which he says is normal, but I'm not so sure. It doesn't happen if I'm at higher RPM/speeds. It's when I'm just driving leisurely and applying throttle at that moment click from the back end area outside the interior.

 

So no one else has this light knocking/clicking noise? I have the GIAC flash on it.

 

It could be something coming from the sway bar mounts?? That would be my first thought. Sometimese you can get a creaking sound from that area.

 

Changing fuel might let you verify if you’re getting an occasional low-rpm knock. Any place around to buy a tank full of higher-octane premium?

 

Yea, I believe it is knocking and I've read other threads in the 997 forum where this seems to be common except I am running a GIAC flash chip done at Sharkwerks. The car is now in Seattle and I believe we in WA state run a 92 octane whereas the fuel in Cali is a bit diff at 91.

 

How do I get a hold of Garret Lim of GIAC?

 

Start here.
http://www.giacusa.com/

 

you can go down to AUburn and put some 100octane race gas in your car from the pump. Or just try adding some octane booster

 

No response from GIAC yet

 

knocking trpically comes from running lower octane fuel in your car than you should. Why not add some octane boost?

Do you think that it could be anything besides your motor?

 

GIAC flash does impact what the motor does and I'm running the same premium gas anyone else is from Chevron/Shell.

Why should I have to deal with pre-detonation on a chip designed to work with a car operated in USA by adding octane boost?

I like your idea of adding race gas and seeing if that helps to target the problem. But ultimately, I need it to work with WA state premium.

 

I never said that the chip doesn't impact the motor, i am talking process of elmination Ben... try something to see if that does the trick.. what if the chip is not what is causing the problem.

Why can it not be something coming from your suspension? You hit the throttle and that does cause your suspension to compress right? Just an idea

 

It's not the suspension. It's a definite predetonation noise.

I'm going back to stock programming to see if that clears it up. Let's say that I go down to Auburn, get myself some race gas and it works out to zero noise. It still doesn't leave me with a viable solution. I'm not going to run race gas.

I appreciate your brainstorming with me.

 

Ben it's not about running on race gas or with octane booster as a solution. it is to see if that is your problem and go from there. Now you are going to have someone program (if you don't have the switch) back to stock program rather than something that is easier?

What does it hurt to try something? If you have the switch than it should have already been done..

BTW: knocking is mainly heard through lower RPM's cause the sound of the motor at higher RPM makes it harder to hear (for one thing); )

 

I understand the logic behind it all, but I just don't wanna go that route.

It's easier for me to drop off my car at my indy and have them go back to stock to see if that gets rid of it v. adding any unusual fluids to my gas tank other than premium Chevron/Shell gas.