2004 Dodge Dakota engine ocilation

2004 DODGE DAKOTA
114,000 MILES • 3.7L • V6 • 4WD • AUTOMATIC
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KENNETHTANKERSLEY
  • MEMBER
  • 1 POST
When driving at about 40 mph or less the rpm's oscillates up and down about 500 rpm. Is this a bad sensor on the engine or does the speed in or speed out sensor on the tranny got some type of issue?
Jan 15, 2014 at 7:29 PM
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JACOBANDNICKOLAS
  • ✓ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
It sounds like you either have an engine vacuum leak or the idle air control valve (IAC) is bad. The IAC is responsible for maintaining the engine idle speed. First, check for vacuum leak issues. If none are found, then suspect the IAC.

If the check engine light is on, have the computer scanned to identify trouble codes. Most parts stores will do it for free. That will help identify where the problem is coming from.
Jan 16, 2014 at 5:27 AM
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