What temp should the gauge reach before the fans kick on in a 99 olds silhouette. mine r kicking on low just at the red mark of hot. my overheat light does not come on and the bulb is good. what could cause this? i have replace all hoses, therm, temp sensor, checked all relays and fuses. when i turn on the ac the fans work properly but not when ac is of.

SOURCE: 1994 Cutlass Ciera Runs Hot

If coolant can be detected inside the car, you need to replace the heater core. After it's replaced, the low coolant light should not come on after the heater core is replaced, and the system refilled. If it does, you need to check further. Go w/ the heater core for now, as it will fog up the inside of the car, and become a safety issue.

SOURCE: temp gauge fluctuates, fan comes on, car jumps in

there is air in the system

Testimonial: "Will give this a try and certainly hope this helps. Thank you"

SOURCE: 97 cutlass running hot an overheating already

it's a 97 so it could be that the fan motor has died, try jumping power right to the motor if nothing hapen's then u will know it's the motor itself

SOURCE: Overheats while Idling.

there are 3 cooling fan reays in a 98 aurora and they are computer controlled. the low speed fan relay should turn on when the ecu detects a temp of 229 degrees and should turn off when the temp has dropped to 216 degrees. it is best to check the temp with a computer monitor so you can see what the computer is reading. If you turn the a/c on you can see if the fans are operating. If they don't come on with the a/c you may have a problem with the high side a/c switch. A bad thermostat can cause the fans to come on late.

SOURCE: i have a 99 olds

well have you checked the fan to see if it works. hook a wire to postive side of battery & hook to one side of fan to see if it runs if not fan bad if does it sensor or relay fuse bad