» » »

Mazda Q&A

Ask Your Question

2003 Mazda Tribute Question: Engine misfires at low rpm in overdrive.

 

Question

brodgers, 3.0L V6, Huntsville, AL, December 29, 2012, 20:27
 Rookie

Starts fine and runs through all automatic gears fine until low rpm (like going up hill) in Overdrive. When it shifts down or I turn off O/D, rpm goes up and engine runs fine. Possibly related, while driving about every 5 minutes all gauges goes full max and hold for 3 seconds, then go to zero, hold for 3 seconds, then go back to normal indications. Cruise control does not drop off and there is no change in engine noise. Vehicle operates normally during gauge fluctuations.

2 Answers
Flag This
  • Answer #1

    December 29, 2012, 20:53
    Profile_thumbnail
     Master

    The first concern sounds like a secondary ignition fault,more than likely a faulty coil or coil boot.I have also had issues with the engine wire harness at the rear of the engine compartment near the pcm connector.I have had broken wires on this harness causing intermittent concerns like those that you noted.A good wiggle test while the truck is running is the easiest first test.Altenators are also a problem with these vehicles,which could cause gauge prove out.

    Reply
    Flag This
  • Answer #2

    December 30, 2012, 03:28
    Profile_thumbnail
     Master

    I agree with answer 1. Good scanner and someone to read it is priceless for this kind of trouble. You have a coil breaking down thats causing the misfire while in od with converter locked! If it were another componet it would misfire under 'various' conditions.
    If you get it scanned and find cylinders 1-2-or3 has a defective coil replace all 3 while the plenum is removed.
    Also all spark plugs with oe type! 4-5&6 are easy to get to! Fixed one with the same problem Friday, same year and eng. but MPV.
    That should take care of the misfire problem. As for the IP (gauges) scanner will help there also. Snap-On Modis is a great scanner.
    When used by someone that knows how to use it!

    Reply
    Flag This
Answer Ranks