1999 Pontiac Sunfire Reving

1999 PONTIAC SUNFIRE
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DEZZIE41
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Engine Mechanical problem
1999 Pontiac Sunfire 4 cyl Front Wheel Drive Manual 145xkm miles

ok heres my problem..i just put in a new motor in my sunfire GT 2.4L the new motor has 145000 KMS on it..i noticed this morning when u start it and after the engine cools down all the way..that when u start it when it is all the way on C on the guage it like to rev its slef up and down between idel and 2600RPM until the temp guage is off C...wut could that be an indication of>???

Thanks
Mar 1, 2009 at 5:23 PM
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F4I_GUY
  • ✓ASE Certified Mechanic
  • 3,302 POSTS
  • ASE Certified Mechanic
This could be an idle air control valve acting up. This valve controls an air passage while your throttle plate is closed. If you hold the throttle down a bit and the vehicle stops surging it is usually an IACV issue.

You can try cleaning the valve/ports/ throttle body first to see if this does any good. If not, you may have to replace the valve.

You should also check for vacuum leaks.
Mar 5, 2009 at 2:12 PM
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DEZZIE41
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tyhere are no leaks in vac lines...and she only does it whene shes codl i cant figure it out
Mar 5, 2009 at 3:11 PM
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F4I_GUY
  • ✓ASE Certified Mechanic
  • 3,302 POSTS
  • ASE Certified Mechanic
It's probably the IACV then.
Mar 5, 2009 at 6:01 PM
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