Started to misfire, surging and vibrate at 30 MPH

Tiny
BELLY35
  • MEMBER
  • 2007 DODGE DAKOTA
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 32,000 MILES
Started to misfire, surging and vibrate at 30 MPH. Little gas and off we go running good. Average mile per gallon is between 18 and 19 city. Have not really take a road trip yet. I have put in full tank 89 Octane to see if that helped. It did a little but still misfired, surging at 30 MPH but not as bad. Problem is worse if going up a small hill at 30 MPH, vibration last longer and can feel the engine surging, missing but once up to a speed over 35 MPH and giving it gas?
Friday, October 1st, 2010 AT 3:13 PM

4 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
It sounds like you might need a tune up or have a bad spark plug-coil (common), injector or low compression to be sure which one it is please follow these videos and guides.

https://youtu.be/QTE8k06MzwQ

and

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

and

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

Let us know what happens and please upload pictures or videos of the problem.
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Friday, October 1st, 2010 AT 11:40 PM
Tiny
BELLY35
  • MEMBER
  • 4 POSTS
The vibration does not happen when coasting. If I slowly approach 30MPH leave off the gas (seconds) start to slowly accelerate I get the vibration and the surging and what feels like a misfiring. As more gas is give and the truck speed up the vibration is gone and the truck runs fine... If I slowly approach 30 MPH going up a small hill. Vibration start and so does the surging. More gas and stops. It sometime start a little at 40 MPH but goes away quickly ( just feels like the truck is surging or misfiring a little...)
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Sunday, October 3rd, 2010 AT 3:57 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
It sounds like a missfire. I have to say, without the check engine light, it makes it difficult. Have they checked things such as the catalytic converters, crank sensor, vacuum leaks. Also, do they feel it could be the transmission? Try this. Put the truck in 2nd gear and slow down to the speed that you feel the problem. See if it still does it and let me know.
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Sunday, October 3rd, 2010 AT 9:43 PM
Tiny
BELLY35
  • MEMBER
  • 4 POSTS
Thank you for your help I followed the guides and found the # 2 spark plug was cracked all fixed!
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Monday, October 4th, 2010 AT 9:36 AM

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