The new Opti did not get rid of the miss I experienced in D. Drove the hell out of the SS last night. Several WOT pulls in OD. No issues. Honestly, at this point I'm so frustrated that I am trying to break her.
On the way back home, I turn onto a road with a long incline while in D. I mash the throttle. She goes. Trans shifts and then the repetitive miss/stutter comes back. Let off the throttle. Miss/stutter goes away immediately. Mash the throttle again. No miss/stutter.
Was able to get the SS up on a proper lift and run it. Funny thing happened. I've never been in a car and run it while up on a lift. So, I'm throttling it while Nab is under it listening and looking for the noise. I had my foot on the brake while giving it gas. Smoke and sparks start coming from the rear brakes. Nab enjoyed the show. BTW, I know I shouldn't have done that. Again, it was my first time and it felt weird giving it throttle up on the lift. I was trying to control the rear spinning. But you know, physics. Safety second! Brakes still work and Nab and I have survived to drive fast and take chances another day.
Anyway, wasn't able to replicate the noise while on the lift but when the SS was back on the ground we got the noise going. Still have not found the source of it.
Trans pan and oil look great. No catastrophic carnage nor signs of impeding doom. Found a very loose heatshield. Rear driver side by the fuel tank. Tighten it up. That fixed some of the other noises I was hearing.
Nab is confident it is not the flex plate and TC. He believes the noise is external to the engine and trans. Sounds like an exhaust and heat shield noise. I'm going to remove the passenger side exhaust ballast/weight. Unfortunately, I did not think to remove it while it was up on the lift. Lifts are great! I was excited and caught up in taking advantage of checking everything under the SS while it was up.
Found the miss...
Back to the parts bin...
Will continue to drive and enjoy the ride until I break her. Feel more confident that we ruled out the big stuff.
Thanks for all the help and support. If I do ever find the cause of the noise, you all will be the first to know.
The exhaust bracket that connects/supports the pipes after the cats. It's mounted to the transmission. One of the bolts was missing. The other was backed out and making contact with the trans crossmember. The bolt had a washer on it.
I discovered it when I removed the passenger side exhaust ballast. After I removed it I banged on the exhaust with my hand and heard the a metallic noise and knew it had to be it. With the SS on ramps and me on my back looking sideways was the right angle to see the missing bolt for the bracket.
Crazy thing is, the bracket is between the crossmember and the trans pan. We had the trans pan off and totally missed it.
View from the passenger side...
From driver side...
Where the bolt contacted the trans crossmember...
Bracket removed. Was unable to tighten it down because the remaining bolt was stripped...
The bracket. Leave it off?
So the recap. I hear a noise. Don't like it. Replaced the tensioner. Replaced the alternator. Replaced the PS pump - just needed a good flush. Replaced the AC compressor - it was leaking. Removed serp belt. There's a miss at WOT. Replaced the Opti. Engine will not stay running. Replaced Opti replacement with another Opti. Changed oil and added MMO. Changed oil and cut open the filter. Changed trans filter. Secured a loose exhaust heat shield. Still have a miss. Changed coil. Removed exhaust ballast. Find the cause of the noise. Done!
Fortunately for me I had most of the parts and did all the labor. Had help from a couple good friends, Glen aka Stumpy and Nab.
What threw me off was the sound of the noise. It really sounded like a rotational metallic noise when giving it throttle while parked or in gear with the brake applied. However, when driven and not at operating temps, the noise was more of a random rattle that went away once the SS was at operating temps.
It all makes sense now. Found a bad AC comp and coil that I would have had to eventually deal with. Confirmed that my engine and trans are in good shape.
Well thanks for joining me on this little adventure.
I thought this thing was stock - but the exhaust hanger bracket had a stripped out bolt hole on the (EDIT) transmission? Sounds fishy to me. Personally, those cats are heavy, and GM doesn't spend a dime it doesn't need to, so I'd put that brace back on. Otherwise every pothole and bump is stressing the rear cat bolts and the exhaust manifold bolts. You could (EDIT) helicoil that one.