Cooling Fan Issue
mercedes84black
04-11-2007, 04:06 PM
I Have A '98 Grand Prix 3.8 Seriesii That Has Overheating Issues. I Noticed The Cooling Fan Only Comes On When The A/c Is On. It Comes On With The Aux Fan And Does Not Spin High Speed As It Should But Does Do Low Speed. I Think It's A Cooling Sensor Or Cooling Fan Relay That Controls The Cooling Fan And At What Speed And Temp It Comes On At. Can Someone Please Verify And Lead Me To The Correct Sensor Or Relay So I Can Change It Out. I Would Be So Greatful
richtazz
04-11-2007, 05:11 PM
What temp are you running? The fans won't kick on until 230 or so when setting in traffic or in hot weather. The fans are signalled to turn on from the PCM through the CTS, so a bad sensor would normally also trip a CEL.
jonsonton
04-12-2007, 01:21 AM
A clogged thermostat could cause an overheating problem as well. Dumb question-Have you checked the coolant level?
mercedes84black
04-12-2007, 08:06 AM
New Thermostat, Water Pump, Radiator And Fluid Level. As I Stated When The Cooling Fan Comes On It Isn't At High Speed As It Should Be And It Only Comes On When I Activate The A/c And In That Case Both Fans Come On But Still Not At The Speed That It Should (on A Standard Vehicle It Would Need A Fan Clutch). I Am A Layman And Don't Really Understand The Terms Richtazz Refers To The (pmc Thru The Cts Or Cel) Could You Explain In Laymen Terms Please. This Info Seems To Make Sense If I Could Just Understand It. In Other Words The Fan Speed Isn't High Enough To Cool The Engine. Although It Doesn't Get Immediately Overheated But The Temp Guage Rises Gradually So To Solve The Cooling Fan Issue Would Solve The Problem So Again Where Would I Find The Sensor Or Relay For The Cooling Fan
GregA
04-12-2007, 11:20 AM
If you want to know more about how the cooling system should work, check out the link below.
It is not for a Grand Prix, but it is GM, and the idea is the same.
GM Cooling System Operation (http://www.my-chevy-venture.com/engine-cooling-system.html)
The Engine Coolant Temperature (ECT) sensor should be right next to the thermostat housing.
The Relays that control the fans should be under the hood, in the Relay and Fuse Center (plastic box).
Take Care,
It is not for a Grand Prix, but it is GM, and the idea is the same.
GM Cooling System Operation (http://www.my-chevy-venture.com/engine-cooling-system.html)
The Engine Coolant Temperature (ECT) sensor should be right next to the thermostat housing.
The Relays that control the fans should be under the hood, in the Relay and Fuse Center (plastic box).
Take Care,
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