Why does my daughter's 2003 Mazda 6 car's engine unexpectedly rev?

My daughter has a 2003 Mazda 6. Several times recently, while she was driving, the engine unexpectedly began to rev. I'm a widow, know nothing about cars. Can anyone give me an idea of what the problem might be, and what might need to be fixed? That way, when she takes it in someplace, she'll have an idea as to what the problem might be, and also have an idea if she is being told the truth...her friend recently had a car problem and the place she took it to told her she needed a lot more work on the car then she did. Luckily, her father knew what was going on and went back in with her and straightened it out. We don't have a man here to help us...and we really don't know much about cars. Any help or advice would really be appreciated. thank you!

2 Answers

Relevance
  • C7S
    Lv 7
    8 years ago
    Favorite Answer

    Give the car a complete Tune Up.

    It is probably due for new spark plugs, spark plug wires, fuel filter, distributor cap and rotor. Parts are usually $80-90 all together. Labor is another $80-90.

    The things I just listed all contribute to rough engine idle, unexpected revving, poor gas mileage and poor acceleration. You need to give a car a tune up every 90,000-110,000 miles.

  • Anonymous
    5 years ago

    On the contrary, engine has everything to do with transmission, especially with an automatic. It's the ECU that does the math and talks to the transmission. Gears are selected according to engine revs - having 5 or 6 does make a difference. It may work, but it will be far from ideal. Other thing - as far as I remember, the engines on 2003 and 2005 were not identical, not major differences, but not identical. Now, you can put anything into anything (theoretically). But I wouldn't do it if the engine replacement wouldn't include the modification of the ECU and all the electronic subsystems. This is not replacing an engine in a '57 Chevy. For all I know you cannot put (without serious mods) a more efficient 5 speed auto into a 2003 2.0 liter Mazda 6 that had a 4-speed auto (European specs).

Still have questions? Get your answers by asking now.