WHY IS THE RADIATOR FAN GO ON AT SLOW SPEED AND RUN FOR A FEW SECONDS GOES OFF?

  • Tiny
  • flwesanya
  • 1999 Mitsubishi Pajero
  • 100,000 miles

1999 Mitsubish Pajero IO GDI(H76W-0032372: My car is overheating. I changed the thermostat. But it still overheats. It ruptured the radiator cover and I had to replace with a new radiator after failing to get the spare part separate. After putting the new radiator I noticed that the fan takes long to come on. And when the fan comes on it runs at a very slow speed for a few seconds and stops before the coolant cools. Now Is it the fan mortor that is failing or what is causing this? If I remove the thermostat from the socket the fan runs at normal speed but the car idling does not stabilise and the engine light in the dash board goes on. Kindly assist me with an answer.

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Monday, June 25th, 2012 AT 9:48 PM

7 Replies

  • Tiny
  • rasmataz
  • Member

Scan the computer for codes/s-start here -let us know-could be the coolant temperature sensor acting up-

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Tuesday, June 26th, 2012 AT 12:13 AM
  • Tiny
  • flwesanya
  • Member

I have done the scan: 'Fun control unit needs replacement'. That is all I was told.

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Friday, June 29th, 2012 AT 8:52 AM
  • Tiny
  • Wrenchtech
  • Expert
  • 20,241 posts

I don't have specific specs on that car but most all of these fans are intentionally designed to come on at higher temps for emissions reasons. Most don't come on until225 of higher and that is normal. As long as the fan is shutting back off, I doubt it has a problem at all.

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Friday, June 29th, 2012 AT 10:03 AM
  • Tiny
  • flwesanya
  • Member

Thanks. Now I am getting confused. What controls the speed of the fun? Because I see that when the fun is eventually started it moves at a very slow speed for a few seconds and then it stops. This causes engine overheating.

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Friday, June 29th, 2012 AT 11:27 AM
  • Tiny
  • Wrenchtech
  • Expert
  • 20,241 posts

As I stated, I don't have a wiring diagram for that car but many have 2 speed systems. It could also be a bad fan motor but you could determine if that's the case by observing how it works with the A/C

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Friday, June 29th, 2012 AT 11:30 AM
  • Tiny
  • flwesanya
  • Member

Ok let me tray and observe. I will come back to you later.

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Friday, June 29th, 2012 AT 11:56 AM
  • Tiny
  • KHLow2008
  • Expert
  • 41,994 posts

No code reader or scan tool would tell you what component needs to be replaced. They only tell you that a certain circuit has a fault.

What is the EXACT trouble code that you are getting?

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Friday, June 29th, 2012 AT 2:57 PM

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