Question about Mazda MAZDA3

1 Answer

My speedometer is fluctuating anytime i let off the gas. as long as i'm accelerating, it does what it's supposed to do. that hasn't affected the way the car drives, though. the other thing that happened is that while i was driving the other day, the engine started to rev up by itself. when i sat at a light, it would go up to about 3000 rpms, then go back down, over and over again. so, i decided to go back home and when i got back to my street, it stopped doing that and started acting normally. i took it to a mechanic and they drove it around and said the only thing they noticed was that the speedometer was doing the up and down thing. they said they wouldnt know what it is unless they could go into the dash. i didn't give permission because i cant afford what they estimated. i'm thinking about taking it to the dealer to let them diagnose it as well.

Posted by on

  • Aaron Murchison
    Aaron Murchison May 11, 2010

    what year is the car? recent work done to the car? millage? engine light on?



1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that gotĀ 5 achievements.


    An expert whose answer gotĀ voted for 20 times.


    An expert who has answered 20 questions.

  • Expert
  • 154 Answers


Posted on Aug 18, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Our 1999 Buick century won't take gas dies out sometimes and now the transmission won't shift and the speedometer quit working at the same time I just put a brand new fuel pump and fuel filter on

Have you scanned for trouble codes? If the speedometer is not operational and the tranny is not shifting, you may have a vehicle speed sensor issue. A scan test should have a stored code for a VSS problem. There may be other codes as well related to the vehicle dying out. It may not be a fuel pump related problem at all. There are numerous sensors that can affect acceleration as well.

Feb 12, 2016 | Buick Cars & Trucks

1 Answer

My speedometer goes up and down , and my radio goes on and off

The speedometer can fluctuate rapidly under normal driving conditions when the car's speed changes abruptly, but sometimes the needle can start swinging around the dial without any fluctuation in speed. If the hairspring comes loose or breaks, it can't hold the speed cup in place, and the result is a fluctuation in the dial. In electrical speedometers, if the circuit that counts the magnetic pulses fails, it can cause the speedometer read-out to vary from the actual speed and to shoot upward or downward without notice. If a speed sensor in the automatic transmission starts to malfunction, it can affect the speedometer and cause fluctuations. In these instances, either the speedometer or the sensor needs replacement.

Sep 26, 2013 | Cars & Trucks

1 Answer

Speedometer jumping

Could be worn out speed sensor.

May 10, 2013 | 1994 GMC Sierra

1 Answer

Why did my speedometer stop working and within minutes my 02 Cadillac Sts stalled and would barely accelerate?

The speedometer and odometer gets a signal from the speed sensor in the side of the transmission where the speedo cable once was.
The problem could be the speed sensor, or something in the wiring, or in the instrument cluster. Or it could be that the transmission is failing internally.

Feb 27, 2013 | 2002 Cadillac Sts

1 Answer

Speedometer fluctuates and power loss

Clean your fuel tank power loss could be caused by water in your fuel line and tank.

Feb 05, 2013 | 1996 Toyota Camry

1 Answer

02' Jeep liberty speedometer is fluctuating between 0 and 90 miles per hour at idle. And if you accelerate it goes to 120 mph and stays there. If you stop at a stop sign/light it starts dinging until you...

The VSS - vehicle speed sensor possibly or maybe the TPS - throttle position sensor . I know TPS sensors can cause an erratic idle ,or surge. Hooking up a professional type scanner to the DLC - diagnostic link connector an checking the VSS input to the PCM - engine computer would be the best way to diagnose . Also checking speed sensor info the PCM sends to the Instrument cluster . Do you know what serial data networks are or computer data lines ? The PCI bus is a communication network for all the modules (computers ) on your vehicle . The modules share information on this data line . It's suppose to cut down on wiring harness size.( # of wires). Your best bet , take it to a qualified repair shop that has the right diagnostic tool's .
006 Chrysler PCI Communications

Nov 08, 2017 | Cars & Trucks

1 Answer

Wont shift out of second, no speedometer, gas gage fluctuates

If the speedometer is not working and the transmission will not shift it is usually caused by a bad vehicle speed sensor. The fuel gauge thing is most likely not related. This is usually cause by a bad fuel level sensor inside the fuel tank.

Jan 30, 2011 | 2002 Dodge Neon

1 Answer

Driving down the road, the speedometer starts to jump as high as 130 mph and as low as 20 mph but the car engine does not rev... when the speedometer drops low, the lights on the dashboard flicker. The...

check your battery and alternator, this is fluctuating voltage causing th einstrument panel to go crazy!! Autozone can check it for you for free!!

May 17, 2010 | 1998 Toyota Camry

1 Answer

1995 Accord: Speedometer/gear indicator/hesitant acceleration.

Purchase a new vehicle and stay from under the hood!

Jun 15, 2009 | 1995 Honda Accord

1 Answer

1998 Buick Park Ave Speedometer stopped working.

Found the problem with the speedometer on my Buick. When you use the magnet to fix the gas gauge, will can and may affect your speedo. So use the magnet trick on it as well. Appears that the manufacturer didn't think about the needles being able to swing past the magnet they have set up in the gauges. Should have put a stop pin on the gauges.

Jan 27, 2009 | 2000 Buick Park Avenue

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

182 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mazda Experts


Level 3 Expert

81400 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8841 Answers

Are you a Mazda Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides