Temperature gauge keeps spiking and then going back down to normal is that an electrical fan issue or a thermostat issue
Temperature gauge keeps spiking goes right back down to normal in both Highway and City driving antifreeze level is ok
My car has 160000 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
Hi There,
It sounds like you may have a faulty thermostat or potentially a cooling fan that may not be cycling on and off properly. As you know, the thermostat regulates the flow of the coolant in your car’s engine and controls when the coolant flows in and out of the motor from the radiator by opening and closing at specific temperatures. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. When the thermostat is stuck open it can cause the coolant to circulate constantly resulting in the motor never reaching the correct operating temperature. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.
It sounds like you may have a faulty thermostat or potentially a cooling fan that may not be cycling on and off properly. As you know, the thermostat regulates the flow of the coolant in your car’s engine and controls when the coolant flows in and out of the motor from the radiator by opening and closing at specific temperatures. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. When the thermostat is stuck open it can cause the coolant to circulate constantly resulting in the motor never reaching the correct operating temperature. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.
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When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot.
Low coolant, a clogged radiator, bad water pump, and a handful of other things could all be a potential issue. Replacing a thermostat is much easier than replacing an engine, so keep an eye on your temperature gauge.
Erratic Temperatures
As we mentioned in the introduction to this blog post, if your temperature gauge on the dashboard is bouncing up and down, the thermostat is malfunctioning. This is a sign that the thermostat is not reading the engine`s temperature correctly and releasing the coolant at the wrong times.
If your engine begins to overheat only when you`re idling, but the needle on the temperature gauge begins to move down once you pick up speed, the most likely cause is that something is wrong with the radiator fan. As you drive, air will flow over the radiator, which helps the coolant get cool again.
This can be caused by a number of things such as low coolant levels, a faulty thermostat, a clogged radiator or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds.
Car coolant is contained within a sealed system, so if it`s in good condition the coolant level shouldn`t change if it`s checked when the engine is cold. The level will rise when the engine is warm because water expands when it`s hot, but it`ll fall back to the `cold` level when it cools.
Overheating can be caused by a number of things such as low coolant levels, a faulty thermostat, a clogged radiator or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds.
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.
Engine Overheating
A failing water pump will cause your engine to heat up, and that`s not a good thing. To prevent catastrophic engine failure, look for these signs of an overheated engine due to water pump failure, including: A fluctuating temperature gauge.
The engine`s oxygen sensor will detect the extra oxygen entering the engine via the vacuum leak which will alert the engine`s computer that the exhaust is running lean, which will prompt the computer to pump in additional fuel, resulting in an abnormally high idle.
It gets even more concerning and confusing when car overheating suddenly returns to normal. This phenomenon can happen for many reasons, like a bad thermostat, a faulty radiator, or a coolant leak. As such, it`s best to get your car checked by a professional— like RepairSmith!
Overheating can be caused by a number of things such as low coolant levels, a faulty thermostat, a clogged radiator or a failing coolant fan switch. As you may know the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Temperature gauge keeps spiking and then going back down to normal is that an electrical fan issue or a thermostat issue
ANSWER : Hi There,
It sounds like you may have a faulty thermostat or potentially a cooling fan that may not be cycling on and off properly. As you know, the thermostat regulates the flow of the coolant in your car’s engine and controls when the coolant flows in and out of the motor from the radiator by opening and closing at specific temperatures. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. When the thermostat is stuck open it can cause the coolant to circulate constantly resulting in the motor never reaching the correct operating temperature. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.
It sounds like you may have a faulty thermostat or potentially a cooling fan that may not be cycling on and off properly. As you know, the thermostat regulates the flow of the coolant in your car’s engine and controls when the coolant flows in and out of the motor from the radiator by opening and closing at specific temperatures. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. When the thermostat is stuck open it can cause the coolant to circulate constantly resulting in the motor never reaching the correct operating temperature. I would suggest having an expert from Your Mechanic come to your home to diagnose your cooling system.
Car overheating
ANSWER : When coolant is re-introduced to the cooling system after a major cooling system repair, the cooling system MUST be purged of air. Indeed, on many vehicles, there are purge points that are intentionally designed into the system to effect purging of air as coolant is added. If the cooling system is not purged of air, what will happen is exactly what happened to you: the car will overheat and as the trapped air finally reaches the top tank of the radiator, you will find that the coolant level is too low. The vehicle should not have been released to you without ensuring that there was no air in the system and/or they should have verbally alerted you to the need to check the coolant level after driving the car a short while (but only when cool, of course) and add coolant as needed. The only other explanation for what happened is that you have a leak but even if the water pump is seeping, you won’t lose such a large amount of coolant. Keep a eye on the coolant level going forward and also be mindful of the possibility that you might need a water pump soon. Some leakage from the weep hole on the pump is OK but if it becomes continual, replace the pump at your convenience so you are not stranded somewhere if the pump seizes and fails. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
I have a problem with the temperature gauge – 2002 Buick Rendezvous
ANSWER : Hello. The temperature gauge is going to elevate based on the resistance of the sensor. The first thing to check is the temperature sending unit. The wires or the sensor itself may be corroded or damaged. This would cause extra resistance in the system and cause the gauge to be off.
You can test the readings coming from the temperature sensor. You will want to test for resistance and match it to the correlated temperature. You can find these specifications based on make and model. This would inform you of what the gauge thinks the temperature is versus what the scanner is reading. If they are off, then you know the sensor is bad and you should replace it. The sensor will signal the computer as to when the fans should be turning on. If the fans are not turning on soon enough, this would be the cause.
I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine if the gauge is faulty and replace the temperature sending unit if necessary.
changed thermostat and radiator, temp gauge goes to hot when sitting still mostly, then goes back down to normal temp. Happens eve
ANSWER : Hi there. If you did not properly bleed the cooling system after completing these repairs, it’s more than likely that you have air bubbles inside the coolant system causing this problem. However, it could also be due to a bad electrical harness or connection to the thermostat or temp sensor on top of the radiator as well. It’s probably a good idea to have a professional mobile mechanic come to your location and complete a car is running hotter than normal inspection, so they can pinpoint the source of this issue and recommend the right repairs.
Fans not working properly and temperature gauge rising – 2004 Toyota Camry
ANSWER : Hello – there are still a couple of possible sources of this overheating. A weak water pump, or clogged (internally or externally) radiator may not be transferring enough heat out of the engine. Air pockets in the radiator where the fan switch mounts would cause the fan not to kick off as expected. It’s also possible with your mileage that you have a blown head gasket, which essentially "super-heats" the coolant, and the cooling system is just not capable of dispersing that much heat. I would recommend an inspection of the cooling system by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.
My temperature gauge is reading hot. Just had my thermostat replace last week. They found no other leaks, pressure test was good s
ANSWER : It’s possible that your temperature gauge is operating erratically which would be an electrical problem (sending unit, gauge, wiring, etc.) rather than an actual overheating problem. The most common causes of overheating include low coolant level, a faulty thermostat, a plugged radiator, a faulty radiator pressure cap, collapsed hoses, non functioning cooling fans, and a faulty water pump or drive belt. Certain engine faults, such as a leaking head gasket or poor engine running condition can also cause overheating. Whether the problem is gauge related (electrical) or actual overheating, if you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine overheating diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
Where is my coolant going? My car keeps overheating and blowing cold air. The temperature rises when stopped and drops when accelerating.
ANSWER : Look everywhere around the engine and see if there is a split hose or loose hose clamp. If the hoses and clamps are in good shape and tight, then check the core plugs (freeze plugs) and see if there is any residue that indicates a leak. If there is no residue or core plug leak, then take the dipstick out of the engine and see if the oil is milky or not. If the oil is milky, then a head gasket is burned and water is getting pushed into the oil system. If the oil is normal color, then the cooling fans may not be working properly and causing the coolant to boil out of the overflow tubes. This would explain why the vehicle overheats when sitting but runs cool when in motion. Check the fans to see if they are working. If the fans are not coming on, then the fan motor relay, fuse, or motor could be all burned out making the fans not work. If you need further assistance with your engine overheating at a stationary position, then seek out a professional, such as one from Your Mechanic, to help you.
Air flow going up and down when gauges go up and down
ANSWER : The electrical system on these vehicles are known to have an issue with fretting corrosion buildup in multiple electrical connectors throughout the vehicle. An affected system would need to have that electrical connection disconnected, cleaned, and a dielectric compound put on the connection to fix the issue. You will need to have a mechanic, such as one from YourMechanic, isolate the failing components, and conduct an electrical problems inspection, such as the one described, for you.
