My vehicle goes over operating temperature when it comes to a stop

My car overheated last week and no I didn't let it go to red on the temp gauge. I took to a mechanic and he replaced the thermostat. Then a few days later the same thing happened. There was too much pressure and the water would rise up from the reservoir. So I took to a radiator specialist and he just told me it was the cap. Everything seemed okay but now when I cruise it's fine but when I'm on traffic it goes over the middle of the temp gauge and I hear the fans come on. This very abnormal for my vehicle because it would Always stay on the center. Last night it happened when I let
Experienced mechanics share their insights in answering this question :
Hi there, thanks for writing in. There are a couple likely scenarios here.

Your water pump is failing, causing it to not pump coolant quickly enough at idle to cool it down.
You have a failing electric cooling fan. There should be 2 fans on your fan assembly, and if one of them is failing, it can cause an issue very similar to this.
You have a partially obstructed or plugged radiator. Blocking the radiator, either externally from airflow, or internally from insufficient coolant flow, will affect the ability of the radiator to do its job, and this may be most prevalent at idle or very low speeds.

I would have a qualified professional, such as one from YourMechanic, investigate those overheating issues, as well as check the vehicle for other potential problems.

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As you drive, air will flow over the radiator, which helps the coolant get cool again. However, when you`re stopped, there`s no air flow. That`s when the radiator fan is supposed to kick in; it creates air flow until your car can get moving again.
A Broken Radiator Fan

If your car begins to overheat when idling, but the temperature gauge moves back down once you get going, it`s most likely due to a broken radiator fan. When the coolant goes to the radiator, it`s spread over a large surface area to cool it down.

The most common reasons for your car temperature gauge going up but not overheating are due to temperature sensor failure, a broken temperature gauge, engine control unit failure, corrosion in connectors, or damaged wires feeding to the sensor or gauge.
If you`re driving your car and the temperature gauge is stuck on high, low, or going crazy, the issue is most likely with your thermostat. The job of the thermostat is to regulate the movement of coolant in your vehicle and maintain the best temperature for engine operation.
One more thing to be aware of: overheating in stop-and-go traffic can be a sign that the engine`s head gasket is beginning to fail. A failed head gasket can allow the engine to burn coolant, keeping the cooling system from working as intended.
Car overheats when driving but not when idling

If your temperature gauge is fine until you make the car work, the most likely issue is coolant flow.

If you notice that your engine overheats, the coolant temperature sensor could be the problem. At times, the coolant temperature switch may fail such that it starts transmitting hot signals permanently. This causes the computer to erroneously counterbalance the signal, thereby causing the engine to misfire or overheat.
The cause may be related to bad wiring, a bad connection, or a problem with the coolant temperature switch, and even a problem with the vehicle`s internal computer. The only way to determine the cause is to contact a professional technician.
Normal body temperature is different for everyone and changes during the day. A high temperature is usually considered to be 38C or above.
If you are not running the a/c system at the time you see the temperature gauge go above the middle of gauge and back down every few minutes then this is normal cycling of the cooling fan.
If you are not running the a/c system at the time you see the temperature gauge go above the middle of gauge and back down every few minutes then this is normal cycling of the cooling fan.

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the most relevant questions and answers related to your specific issue

Is there vibrations and humming that gets louder when speed is increased then stops when vehicle stops a wheel bearing problem
ANSWER : From what you describe it is the front wheel bearings in the front hubs that need replaced. You should also check the tires for uneven wear and need for tire rotation or alignment issues causing uneven tire wear.

My vehicle goes over operating temperature when it comes to a stop
ANSWER : Hi there, thanks for writing in. There are a couple likely scenarios here.

Your water pump is failing, causing it to not pump coolant quickly enough at idle to cool it down.
You have a failing electric cooling fan. There should be 2 fans on your fan assembly, and if one of them is failing, it can cause an issue very similar to this.
You have a partially obstructed or plugged radiator. Blocking the radiator, either externally from airflow, or internally from insufficient coolant flow, will affect the ability of the radiator to do its job, and this may be most prevalent at idle or very low speeds.

I would have a qualified professional, such as one from YourMechanic, investigate those overheating issues, as well as check the vehicle for other potential problems.

Low coolant light comes on when AC, defrost or heater is on, but only if the car is in gear and stopped, what’s wrong with my car?
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.

When accelerating after a complete stop, turning corners, coming to a complete stop or randomly when Parked a very odd vibrating
ANSWER : Hello, thank you for writing in. The vehicle may be suffering from several different issues. In this type of situation you want to start with the least complicated option, and work your way up. Start by making sure your tires are properly inflated, and have them balanced. Your brakes may be playing a role, and you will want to start by cleaning them off with some brake cleaner, and make sure nothing is stuck between the pad and the rotor. You can then raise the vehicle and manipulate the wheel looking for excess play, damaged axles and joints, and damaged wheel bearings. From there you may need to look into the wheel assembly itself and make sure there is nothing mechanically wrong, dirty, or damaged. For more help diagnosing or resolving the vibration issue, contact our service department to schedule an appointment.

What would cause my 2008 Dodge Carvan to shut off when coming to a stop?
ANSWER : Hello. It sounds like you have an issue with the vehicles idle control system. When coming to a stop or when parking the vehicles computer must adjust the idle in order to keep the engine from stalling from the lack of air. Most of the time this is as easy as cleaning out the throttle body. In some other cases it may be caused by a faulty idle control system or even an issue with the vehicles variable valve timing system. I usually clean the throttle first to see if it takes care of it. If you are planning on having this repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the vehicle is stalling] https://www.yourmechanic.com/services/car-is-stalling-inspection

Stop at stop sign, give it the gas, it want go, let up, push down agin it goes,the engine does not die.!!!!
ANSWER : What you are describing sounds like 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.

I have exhaust coming into the cabin via the air vents, and much more when the vehicle is stopped. Air filter or leak somewhere?
ANSWER : The air filter is not a cause of the problem you are describing. Nevertheless, if the air filter has not been serviced as required be sure to change it as that filter is important. Sometimes wind conditions, not to mention other traffic, can be the source of exhaust odors in the cabin. However, if you suspect that the origin may be your own vehicle, due to a leak, please request an exhaust system inspection – suspected leak and the responding certified mechanic will get your concerns addressed. If you have further questions, do not hesitate to re-contact YourMechanic as we are always here to help you.

My transmission will not downshift at a stop, upshift from a stop, or go in reverse.
ANSWER : Hi there. Most transmissions have shifting issues with the fluid being dirty. First replace the transmission oil filter and do a transmission oil flush. If the fluid is black, do not attempt to change the fluid as it will make the transmission no longer work. Then drive the vehicle and see if the transmission will act up again. If it does, then either the transmission control system (valve body – brain of the transmission) has a mass cross leak or the transmission is slipping and needs rebuilt or replaced. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your transmission.