Hey guys,
I am curious. I have a new aluminum radiator that I am putting in my 06 and I was wondering if it is ok to have the car self burp, or should I manually burp it before I start the car?

 

Do it manually.
Run it with the Heat ON Full.
Once the Stat opens and Coolant circulates, ... keep adding a little as the air works its way out.

 

Looks like 3.5 and 3.9 do not have bleeder in the cooling system but here is the procedure for it

***edit*** looks like the same with the ls4 (5.3) so your covered across the board depending on which you have

Cooling System Filling (LZE, LZ4, LZ9 Static Fill)

Filling Procedure

1. Close the radiator drain ****.
2. If a complete engine block drain was required, install the coolant drain plugs to the engine block. Refer to Draining Fluids and Oil Filter Removal for the 3.5L engine or to Draining Fluids and Oil Filter Removal for the 3.9L engine.
Important: Use a 50/50 mixture of DEX-COOL antifreeze and clean, drinkable water.
3. Slowly fill the cooling system with a 50/50 coolant mixture until the coolant level is visible and stable. Refer to Approximate Fluid Capacities.
4. Install the pressure cap loosely (threaded on about one turn).
5. Start the engine and raise the engine speed to 2500 RPM and hold it there for 40 seconds, then shut engine off.
6. Remove the pressure cap and fill the coolant system until the level is visible and stable.
7. Install the pressure cap loosely (threaded on about one turn).
8. Start the engine and raise the engine speed to 2500 RPM and hold it there for 30 seconds, then shut engine off.
9. Remove the pressure cap and fill the coolant system until the level is visible and stable.
10. Install the pressure cap loosely (threaded on about one turn).
11. Start the engine and raise the engine speed to 2500 RPM and hold it there for 20 seconds, then shut engine off.
12. Remove the pressure cap and fill the coolant system until the level is visible and stable.
13. Install the pressure cap, fully threaded on.
14. Fill the coolant recovery bottle to the indicator line, then add 400 milliliters (13.5 ounces) more.
15. Start the engine and run it above 2500 RPM until it is hot enough to open the thermostat, this will allow the trapped air to be purged from the engine.
16. Complete a series of three, 4-second-duration idles with 4-second-duration 3000 RPM cycles.
17. Turn the engine off and allow it to cool down to room temperature.
18. Fill the coolant recovery bottle to the indicator line.
19. Inspect the concentration of the engine coolant using the J 26568 .
20. Rinse away any excess coolant from the engine and the engine compartment