a slightly higher idle at cold starts is an indication that you do not have the added vacumn chamber for the brake fix. The whole frickin engine requires vacumn to operate properly. Think of the higher idle as an air compressor. If you cold start you can see this happening by watching your analog boost guage. it will start at 0 and over about 30 seconds build -20 vacumn.

now, another way to see if you have the brake fix. cold start, then immediately drive... try your brakes....2nd step if brake fix wasn't done... change your underwear.

the bad bearing type sound you hear is a pressure plate opening while trying to build vacumn, again only on cold starts. The engine leaks pressure after about 4 hours and needs to rebuild on start-up.

as for a rough or hicupping idle, try opening your gas cap, if it flutters even more then your EVAP Sensor on the intake manifold is going out. This is a very easy fix, and only a $25 part. (1 screw, 1 clamp on hose, 1 sensor plug) Your car will still run very well even if this part is bad, but will give the rough or fluctuating idle.

If your tuned there are 2 stickers to look for. One is affixed to the air-box cover and has a GM Performance header with a checkered border. The other sticker is located inside the gas cap door, and says premium fuel only.

Hope this helps

 

Hey rainman, tomorrow at the donut house sounds fine. Thx for taking time out of ur day!

Foolmoon, that give me some relief about the pressure plate. I couldn't figure out what it might be except something luubricated that would drain to the bottom when the car was off.
Since it sounds like I don't have the brake mod, is that still a free option for me or would I have to pay?

 

Here's an update:
I went to a chevy dealer and they said they couldn't find a tech directive about the brake fix. They did find something that applied to the non-panel SS's with automatics, but since I have a panel it doesn't apply to mine. Does anyone know the service number or whatever that says chevy will add the vacuum booster for free?

 

You may want to start a new thread for your question. This post is kind of buried here and may not be seen good here.

 

Good Idea. Thanks!