The ICM and MAF sensor are also suspect, especially if they've been replaced with poor quality no name parts.

Also check lower control arm bushings, worn bushings will cause pulling problems.

Welcome, read this and search the site for more help.
https://www.pontiacbonnevilleclub.com/f ... 32865.html

What are the high and low pressure readings?
Although the line is cold the refrigerant level may be incorrect and/or have air & moisture in the system due to improper recharging. I would recommend evacuating the system, pull a vacuum and then add the correct amount (weight) of 134a. IIRC the A/C ...

What brand?
In my experience an OEM equivalent is best, Hitachi is a reliable replacement.

Also, did you have the stumbling issue before the maintenance/repairs listed or afterwards?

Come on people learn to read, He has replaced: Spark Plugs, Wires, Coils, ICM....so telling him to re-replace these things without proof they are bad out of the box is a waste of his time and money.

Sir, My best guess from the symptoms and given what you have already changed is either a faulty ...

corsair- "When I hear the turn signal/hazard (fast) clicking, it seems to be coming from just behind the switch button".

Typically fast/hyper flashing is due to a burned out bulb.
Have you checked the bulbs?
Did you change any bulbs to LEDs?

The critical item is the misfire, was that resolved? After that is repaired, clear the code(s) wait to see if the MIL stays off.
Do you have a code reader/scan tool?
Separately, I would suggest bringing the car to a recommended repair shop if further work is needed.

Ignition wires are suspect, if they're original or over 5 years old replace. I recommend using OEM quality- Delco, Delphi or Denso. Funny all begin with D!
You can check at night using a spray bottle filled with water. Carefully spray the wires, if you see any sparking consider that your smoking ...

A blinking MIL is usually a misfire, could be a simple as a disconnected ignition wire on the exhaust manifold.
Did you open the hood for an inspection?
How many miles?
Is maintenance up to date?

Must be so frustrating, to add to the other advice;

Since the noise is also heard at idle, try removing the belt to see if that alters the noise.
Separately, many years ago I experienced an elusive noise which was due to a loose torque convertor bolt.

A faulty and/or low quality replacement MAF sensor can cause problems. Disconnect and see if there's any improvement.

An exhaust leak will not cause a misfire.
Did you use OEM equivalent wires and plugs?
Confirm firing order is correct and wires are fully seated.

As asked earlier, has the upper intake manifold and gasket been replaced?
How many miles?
Did the random misfire start randomly or after a repair?
After changing all the parts listed, was there any change?

Also, did you check/swap the fuse and relay?
ps I was fan of Smokey and best *dang* garage in town!

Are you using a brand name, GM, Delphi or Denso replacement?
Have you inspected the wiring and connector for damage?

Agreed, it sounds like the cable may have snapped, not sure why you think it's a "busted rotor"

Window regulators have been problematic, here's a link with some helpful info. Search BonnevilleClub site for more good info. Good Luck

http://www.pontiacbonnevilleclub.com/fo ... 48951.html

I think your problem is still trapped air, what procedure are you using to bleed the system?
Did you inspect the flexible lines for damage?
A hard brake pedal with the engine off is due to no vacuum at the booster.