Coolant

ENGINE COOLANT
- Use a 50/50 mixture of clean, drinkable water and GM Goodwrench DEX-COOL (orange colored, silicate free) or Havoline DEX-COOL when coolant is added or when coolant is changed. Refer to Service and Repair for draining and refilling procedure.
- Add two engine coolant supplement pellets (GM P/N 3634621 or equivalent) when refilling the system.

Notice When adding coolant, use DEX-COOL coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result.
Mixing conventional green coolant with DEX-COOL will degrade the service interval from 5yrs./150,000 miles to 2yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL.