Your "operators manuel" should explain which type of oil to use. I have a 96 Buick, LaSabre, that uses 10/30 wt.
A 2000 Buick uses Dexcool.
Regular antifreeze such as, green, or red!
This use to happen on our GMC Suburban. Turned out it was the battery connection. Make sure battery connections are tight and that the battery is clamped down so that it does not move around.
Green
You can use Prestone.
The official coolant is Dex-Cool (orange). However, you can use yellow. Do not use green
Use the green color.
Any brand-50/50 mix. you can buy it ready to use if you like.
Green.
You should use the orange Dexcool, if you cant get it, you can use the green stuff as long as all other coolants are out of your radiator. Mixing different colored antifreezes makes a viscous, sludgy antifreeze.
For a 2004 Buick Rendezvous, it's recommended to use an antifreeze that meets GM's specifications, specifically a Dex-Cool antifreeze/coolant. This is an orange-colored coolant formulated for long-life performance and is designed to protect the engine and cooling system. Always ensure to mix it with distilled water in the appropriate ratio, typically 50/50, unless otherwise specified.