When I stop at the stop light or a stop sign my car shuts off.

ANSWER : It sounds like you may have a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

ANSWER : This may be a result of a dirty or failing idle air control valve. The idle air control valve reads the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. Since this valve is controlled by the vehicle’s computer, it will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your idle air control valve.

ANSWER : First, you want to make sure your cooling system is full. Check the radiator not the coolant jug. And check it when it is cold. If it needs coolant, add some. Of course, I don’t feel this problem is an actual low coolant condition. I would expect to find an electrical failure in the instrument cluster or from a component or wiring harness that is connected to the instrument cluster.

As a technician, I have access to reports from technicians across the country. I could not find any reports of this problem, so diagnosing this will require an experienced tech as this is not a common problem. In addition, this happens at intermittent times making it difficult to recreate. The most challenging part of this diagnosis will be recreating the symptom. I suspect it has something to do with the brake switch circuitry because it only seems to happen when you have your foot on the brake. I would begin my diagnosis there with a wiring diagram and test light in hand. The brake switch, instrument cluster, and environmental controls all interact with each other. Something is crossed either because of a failed module or damaged wiring in a harness.

Aside from making sure the coolant is full, this will not likely leave you on the side of the road. If you take it in to be diagnosed, be prepared for them to spend more time than usual to figure it out. Since it isn’t a key problem, you may need to live with it until it completely fails making it much easier to diagnose. Either way, I do recommend having a certified mechanic diagnose the warning light to make sure there isn’t anything serious going on.

Good luck.

ANSWER : Hello. This can be caused by a number of things. Most of the time if this only occurs when coming to a stop it is because the computer is not maintaining a high enough idle. This can occur because of a failing throttle body, or a problem within the engine or an intake manifold leak. This engine does have a common issue with valve seats failing causing an idling issue. I would usually start by cleaning out the throttle body to see if that corrects it. If it does not then the throttle body may need to be replaced. If the idle speed is fine then you may have a bad connection. I have seen a lot of grounding issues. Most of the time it is because of a bad ground on the engine or a bad connection at the battery ground cable. All of these need to be cleaned and tightened. If you need some assistance with this, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the electrical system is acting like this] https://www.yourmechanic.com/services/electric-problems-inspection

ANSWER : Hi There,
It is normal for the oil and battery lights to come on when the car stalls. When the engine is not running and the key is in the ON position, you will see these lights light up as the car’s computer prepares itself to operate by running through a series of checks. The stalling and then re-starting after the vehicle has a chance to cool is likely related to a faulty ignition coil. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly. The insulation develops small fractures that open when heated and close when cooled. When open, they allow shorting of coil windings and decrease or eliminate the coil’s ability to function. This type of temperature cycling happens because every time you shut the engine off, the fan stops running, the coolant stops flowing and the temperature under the hood rises. Every time you start the engine again the coolant flows, the fans turn on, and the temperature drops. When this heat dissipates and is absorbed under the hood, it is trapped causing this cycling effect. Other components that contain heat sensitive materials include parts like fuel injectors, igniters, and some sensors. Any of these may be potentially subject to this same kind of heat cycling problem which can be very difficult to trace. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle.

ANSWER : Hi there. The best way to diagnose if you have a fuel pump problem is to listen carefully when you turn the key past the accessory setting. If you turn the key forward, but not all the way, you should hear a buzzing sound towards the rear of your car. This is the fuel pump priming the fuel lines. However, if your having difficulty starting your Mazda, it could be other fuel system components or ignition parts that are the root source of your issue. Due to this fact, it’s best to have a professional mobile mechanic complete a car is hard to start inspection at your location; so they can pinpoint the source of your hard starting issue and recommend repairs that will resolve the problem.

ANSWER : Of course, don’t switch gears without being fully stopped, unless your Owner’s Manual or the manufacturer has alternative advice. However, the gear shift issue has no relation to the no-start problem you are describing. Inasmuch as you only have 6,000 miles on the car, the "constant on and off" that you believe has occurred is meaningless in comparison to the expected total vehicle service life. That is, assume what you perceive as "constant on and off", during merely 6,000 miles, might be equivalent to using the car "normally" for three years. A new car should be trouble free for at least 5 years, unless there is a defect, so your "constant on and off" is not a causal factor for any fault on the vehicle. What you might have is a defect in the ignition switch, or perhaps the immobilizer system, but if the problem is not in the switch itself, clearly there is an electrical problem.

If your vehicle is under warranty, by law the dealer MUST repair the issue you are describing within a prescribed time frame and number of "attempts", otherwise the dealer will run afoul of Federal and state Lemon Laws that give you very specific rights, and recourse (contact an Attorney; we are Mechanics, NOT attorneys). Consequently, if the vehicle is still under warranty, to save yourself money do be sure to seek a resolution from the dealer. If the vehicle is not under warranty, obviously a certified Mechanic from YourMechanic could identify the electrical fault and resolve this for you. If you want to go that route, please simply request a no start diagnostic -electrical system and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hello. When this occurs, the first thing I do is try turning the engine over by hand. If I cannot turn the engine over by hand, then I know that the engine is seized. If it is seized, then it will need to be replaced. If the engine will turn over by hand, then the issue is electrical. In that case, I start by testing the voltage going to the computer and the ignition switch. I always check all of the fuses first, and then follow the circuit from there. If you need to have this inspected, consider YourMechanic, as a certified technician can come to your home or office to diagnose the no start and advise you on the best next steps.