GM Service Manual Online
For 1990-2009 cars only

Diagnosis of the cooling system should begin with a visual inspection of the vehicle. Begin with the easiest inspection first.

  1. Check coolant level. The coolant level can be viewed at the coolant recovery reservoir.
  2. Check condition of the air deflector at the front end of vehicle. Any deflector damaged or missing must be replaced.
  3. Check front of vehicle and underhood for dirt, leaves, insects or any foreign matter. Any obstruction of air flow to the condenser or radiator can cause engine cooling concerns.
  4. Check condition of hoses and lines in the cooling system. Any line kinked or hose damaged should be suspected as a problem and replaced.
  5. Check for worn or loose drive belt. A faulty drive belt can cause poor performance.
  6. Turn on A/C. Listen for cooling fan operation. If the cooling fan does not operate with the compressor engaged, refer to Cooling Fan Inoperative, Chart 3 in Engine Cooling System Complaint/Condition Chart .