If your car temperature gauge stays on cold even if the engine is warm, there are some common reasons why this problem occurs. Find out in this article.
- Od Magnuse Selléna
- Aktualizováno: únor 22, 2023
Are you having problems with your coolant temperature gauge staying on cold, even if the car engine is obviously warm?
One of the most important things to keep track of in your car is the coolant temperature because some horrible things can happen to your engine if it overheats.
In this article, we will talk about the coolant temperature gauge and what you can do if this issue occurs.
7 Reasons Why Your Car Temperature Gauge Stays on Cold
The most common reason why your car’s temperature gauge stays on cold is a faulty coolant temperature sensor. It can also be caused by bad wiring between the cluster and the sensor. In some cases, it can also be a stuck thermostat causing the engine not to heat up properly.
Let’s go a little bit more into detail about the different causes. Here is a more detailed list of the most common reasons why a temperature gauge stays on cold.
1. Vadný snímač teploty chladicí kapaliny motoru
As we talked about, the most common problem with a faulty engine temperature reading is the coolant temperature sensor itself sending wrong information to the cluster.
Some cars have two temperature sensors, while other car models have just one. The models with one sensor usually use the same sensor for both the engine control unit’s temperature and the gauge.
If your car model has two coolant temperature sensors, one is used by the temperature gauge, and the other one is used for the engine control module.
Engine temperature sensors are easy to measure with a multimeter, but you need to find the correct values for them. You can also find more information on how to test them in a repair manual. We will talk more about how to diagnose the sensor properly later in the article.
However, if you decide to replace one of them, and your car has two sensors, you should make sure to replace the sensor going to the temperature gauge.
2. Broken Wirings
If you have two temperature sensors on your car (one separate for the gauge), you need to check the sensor’s wires to the gauge or ohm measure the sensor from the cluster connector.
If you have one sensor for both of them, there could either be a problem with the wires between the sensor and the ECU (most likely) or a wiring problem between the gauge and the ECU. Check for any broken wires between these components.
The best way to find broken wiring is to measure the resistance with a multimeter from all the wires’ directions. However, this requires a bit of electronic car knowledge, and you may have to let your mechanic take a look at it without it.
You can also find information about this in your repair manual. Check a wiring diagram of your car to measure the wiring correctly.
3. Faulty Gauge/Cluster
The next problem is a faulty temperature gauge. However, most temperature gauges are integrated with the instrument cluster on modern cars. In some cases, you can replace the temperature gauge or repair any bad solderings if you find any.
In other clusters, you might have to replace the whole instrument cluster. You can often take your instrument cluster to an expert to repair the soldering if you do not know how to do it yourself.
A faulty cluster is not a very common problem, though, and they are often pretty expensive and need programming after replacement. Therefore it is recommended to check the other things first before you decide to replace the cluster.
You can also test the cluster temperature gauge with an Ohm tester if you have some knowledge.
4. Corrosion in plug connectors
Corrosion in the connectors is also a common problem when it comes to a faulty temperature gauge. Clean and spray electronic cleaner in the connector at the sensor, the engine control unit’s connector, and the cluster’s connector.
If corrosion appears, there might be a problem with the connectors’ sealings, and you may have to take a look at these to make a permanent repair or to replace them to avoid future problems.
5. Špatný termostat
The thermostat restricts the coolant from flowing through the radiator. If this gets stuck wide open, the temperature might not reach the optimal level.
However, this will often make your temperature go up a bit from the minimum mark if you drive hard enough. If your temperature gauge is going up slowly, you might have a problem with the thermostat.
You can read more about thermostats here: Faulty Thermostat Symptoms & Causes
6. Air in the Cooling system
Air in the cooling system can also cause the temperature gauge to stay cold if there is an air bubble right at the sensor spot. This can also often be indicated with a fluctuating coolant temperature gauge.
If you suspect air in the coolant system, you have to bleed your coolant system with a unique bleeding technique. If you want to learn more about this, you can check out our guide: Coolant Bleeding.
7. Rozbitá řídicí jednotka motoru
This only applies if your car uses one combined temperature sensor with two pins.
In some rare cases, your engine control unit could be a problem if the temperature information is received first by the ECM, which therefore sends the data to the cluster.
If this is the case, you have to check the trouble codes with an OBD2 scanner in the engine control unit to see if the engine control unit receives the temperature information.
If you can find the temperature readings in the engine control unit but not at the cluster, you have to make sure that they are using the same sensor. If this is the case, you have to measure the temperature output on the engine control unit. To do this, I recommend letting a car electronics expert do the job for you.
You do not want to replace the engine control unit if there’s nothing wrong with it because they’re often costly and require coding.
How To Fix A Car Temperature Gauge That Stays On Cold
To fix a car temperature gauge that stays on cold, you will first want to read the trouble codes with an OBD scanner and then diagnose the coolant temperature sensor. You’ll also want to inspect the wiring and check the thermostat.
1. Přečtěte si poruchové kódy
Whenever you have a problem related to the engine of modern cars, you always want to read the fault codes with an OBD2 scanner. These codes will give you a lot of valuable information, and you can save a lot of money and time by doing this.
For example, if you find a code related to the temperature gauge, you want to start diagnosing there. We have a trouble code library here at Mechanic Base where you can find information on many trouble codes you may encounter.
2. Diagnose Coolant Temperature Sensor
When you have problems with your car’s temperature, you want to locate and diagnose the coolant temperature sensor first. Keep in mind that cars may have a separate coolant temperature sensor for the engine and for the radiator fan, so you’ll want to check a repair manual to make sure you’re looking at the correct sensor.
Once you find the sensor, you’ll want to find the correct ohm values from a chart that matches your car model, then measure the sensor with a multimeter. If you get faulty values from the sensor, it’s time to replace it.
3. Test The Thermostat
You also want to make sure that it’s not actually the coolant that is cold, caused by a stuck open thermostat. To measure the thermostat, you need to use a laser thermometer and check the temperature coming out of the engine.
If you see warm coolant coming out of the engine, even though the engine is not hot, you probably want to remove the thermostat and check its functions.
4. Kontaktujte profesionála
Modern cars can be quite difficult to work on if you don’t have the right knowledge and there is no shame in asking for help. While taking your car to a repair shop can be expensive, it doesn’t necessarily have to be because mechanics are often quite quick to diagnose problems like this.
If you don’t have the right knowledge, you can waste money replacing parts that are fully functional and in this case it would be cheaper to take it to a mechanic in the first place.
Is it bad if my car temperature is cold?
Yes, if your thermostat is stuck open and the engine never gets up to operating temperature, it’s bad for the engine and fuel consumption in the long run. The car engine is most efficient when it reaches operating temperature, and it will also wear less on the engine parts.
Jak odlepíte zaseknutý termostat?
The only way to loosen a stuck thermostat is to do it manually by removing it. But if your thermostat is stuck, you’ll most likely want to replace it, or you could end up in the same situation in the near future. They are quite inexpensive.
Jak poznám, že je můj termostat zaseknutý?
One way to tell if the thermostat is stuck open is to check the outlet radiator hose. The hose should not have any coolant circulation while the engine is warming up and, therefore, should remain cold until the engine reaches operating temperature. If it is the same temperature as the inlet hose during the heating process, it is probably stuck open.
How do I reset my temperature gauge?
There is no way to reset your temperature gauge in most car models. If you have a rare car model where it’s possible, you need to check a repair manual for your particular car model.
Proč investovat do čističky vzduchu?
The temperature gauge staying cold is a serious problem that needs to be fixed. This can be done by checking the cooling system, engine components, and electrical system. It’s not good for your engine to run without reaching the operating temperature; this will cause wear and tear over time.
If you are not comfortable doing this yourself, take it to a mechanic or dealer. With proper care and maintenance, your car will last longer and perform better.
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Související příspěvky
17 thoughts on «7 Reasons Your Car Temperature Gauge Stays on Cold and Fixes»
Hazel Kay Mayfield Reply
1. prosince 2020
I have a 2011 mazda cx9 i replaces valve cover gaskets and coil packs now the temperature gage reads cold whwn running and 1/2 way when car is not running but key on the on position what could be the problem??
Doris Beavers Reply
Listopadu 18, 2020
I have a 2002 dodge car van and my temp stays cold I’ve put coolent in it and it heated up a few minutes then on the way home it got cold again not understanding why
Milind N. Deuskar Reply
Listopadu 16, 2020
Car petrol Indica zeta 2007 car runs for 30 km. Then temperature indicator zero or lowest. Giving me check engine & tripping car ac. Temperature indicator, sensors, cable fault possible problem
Devon Smith Reply
Října 18, 2020
1994 Chev S10 4.3L. Temp Guage doesn’t move at all. Driove %0 mile round trip and guage didn’t move at all.
Toy Corbett Reply
Října 13, 2020
I have an Audi A6T 2002 model. The low water warning is on and flashing on the led display and does not go off after topping up with water, also I noticed that the water temperature gauge is not moving from the bottom. It looks like there is a tiny bit of scum in the water reservoir; I don’t think its oil. Any ideas please.
Července 13, 2020
Had both of my sensors replaced on my 2004 marquis and still cannot get the temperature gauge to work. Is there a sending unit for this car. I thought it could be the instrument cluster but I’m confused because everything else on the cluster works.
Ok i have a 2014 nissan sentra am in the process of changing the oil or fluid from the transmission. My question is that do i have to remove just the overflow tube o do i have to remove the oil pan aswell? Also do i have to monitor the CVTF temperature?
Timothy samuel Reply
6. března 2020
I have issue on Toyota Corolla 05 temperature sensor which I have change temperature sensor and cluster still not working but I find out I that it work Rich the engine control box but the cluster not moving.what cause
I own a 2008 Chevy trailblazer Sometimes my thermostat Gauge works sometimes it does notBut it always blows hot airIt is never cold I had the Sensor replaced in it Still doing the same thing Could it be my thermostat
I have 2007 pontisc g6 2.4 temp gauge worked fibe then noticed it was stuck on lowest teading n the check engine light had came on took it auto parts place said was sensir or liw coolant or thetmostat well car heater is great and was on fill line in coolant as i left the parts store i noticed the needlecwas workibg again which it did for 2 days n onve again stuck on lowest reafinh just by touchibg sensor to assurecit was snug n placevit started working sgain so that mean the sendors not actually bad n could b lisecwire?
Cathy styles Reply
Září 23, 2021
My tempature gauge goes to right before the middle and doesn’t say it’s hot when it is hot. Because the coolant isn’t wanting to flow through the engine??
13. prosince 2019
Last spring I flushed the radiator on 1999 mazda b3000. This winter thermostat kept sticking so I had it replaced with new thermostat. Problem is.. The gauge stays on cold, truck got boiling hot on a short 2 mile drive. Waited for it to cool off then drove home with no problem at all. The guy said it could be air bubble or trash in the radiator. Gauge still stays on cold.
Listopadu 22, 2019
Hi my daughter has a Peugeot 207 1.4 petrol. It has had a new thermostat which then made the temp gauge work. Solved! A year or so later — stopped working again. I changed the coolant today got 4 litres out and put a new lot in 4L. (It’s idd that the system is supposed to hold 5.3L). Anyway, there was no bubbling or rising liquid or anything , just gently filled it to minimum ran engine watched it drop kept filling until 4 L was put back and it was on maximum. Question is — why did it not need 5L and why does the gauge not work?
Collins Nweze Reply
Června 15, 2019
Thanks Magnus for the information. My Lexus 350 Rx 2008 model just had overheating problem without me noticing it on time. Reason was that the temperature guage was not working. It stays permanently at the safe zone, middle and I never suspected it was overheating until the cr stopped. When I checked the dashboard, the temperature guage was still at the middle and I continued my journey until the car stopped again. And I noticed that the engine was hot and the water in the radiator pouring out. My mechanic checked it and said the gasket has been damaged and is being replaced. Luckily for me, although the oil in the engine has not yet mixed with water, but it is blackish in colour. What steps should i take after the gasket fix? How do I know that the temperature guage is working to avoid being disappointed when it need it most?. Thanks, Collins, Lagos- Nigeria
Mario Martinez Reply
Června 15, 2019
Hello! Thanks for the information. I have a 2012 Ford E350, 5.4l v8 that has a temperature gauge that works intermittently. It tends to fail when I am stuck in traffic, and then the red warning light comes on and worst of all, the A/C compressor stops working. Sometimes, all I have to do is turn the engine off for a minute after getting out of traffic, and if I get going on normal traffic, everything works fine, gauge and A/C, but other times it will stay the same, and sometimes it will do it even if I am cruising along on the freeway. Any ideas? Btw, I am not a DYI person, I have two very good mechanics I trust, and they are both stumped.
Listopadu 13, 2019
I have a 2001 Ford e250 van with a 42 litre engine and my problem is my gauge stays on cold all the time I replaced my coolant temperature sensor and same problem then I put a jumper on the connector and the gauge went to hot and then I noticed that when I scanned my codes the temperature read 180 on the scanner so that led me to believe that my problem is some were between the computer and the gauge so now my question is how do I find out exactly were and how to find out
Have you ever been driving your car and noticed that the temperature gauge drops to cold? This can be a worrying sign, as it can indicate a serious issue with your engine. But what exactly is causing this problem? In this blog post, we’ll break down the possible causes of a cold car temperature gauge while driving and how you can fix it.
The car’s temperature gauge can drop to cold while driving for a number of reasons – these include a faulty thermostat, problems with the fan array, a faulty temperature sensor, or an electrical issue with the temperature-sending unit.
How Does a Temperature Gauge Work?
The temperature gauge works by measuring the temperature of the coolant that runs through your engine. This coolant is used to keep your engine from getting too hot, so understanding its temperature is key.
The temperature gauge works by connecting with a sensor that measures the pressure and temperature of this coolant and then sends this information to an electronic control unit (ECU). This ECU then transmits signals to the dashboard, where this information is then displayed as numbers on an analog or digital display.
Click here if you are experiencing issues with the temperature gauge fluctuating while driving.
Why Is It Important to Monitor Coolant Temperature?
It’s very important to monitor your coolant temperature for several reasons. First, if it gets too high, there can be permanent damage done to your engine—the higher temperatures can cause metal components like pistons and cylinders to expand, leading to permanent warping or deformation.
Additionally, if temperatures get too high over prolonged periods, oil seals can break down and start leaking, leading to more serious problems.
Finally, when temperatures are higher than normal, they can cause air bubbles in your coolant system, which reduces efficiency by preventing smooth flow throughout the system.
What Are the Potential Causes?
Vadný termostat
A faulty thermostat can cause your car temperature gauge to drop to cold while driving. The thermostat helps regulate engine temperatures by regulating how much coolant flows through the system.
If the thermostat becomes stuck in the open position, a continuous coolant flows into the radiator, causing the engine to run cold. Overcooled engines run inefficiently, which leads to increased fuel consumption and higher emission levels, and engine parts endure more wear.
When the thermostat fails to close, it causes a continuous flow of coolant into the radiator, resulting in an engine that is running at a temperature lower than optimal. This process can lead to a number of issues, such as lower fuel efficiency and higher emissions, as well as increased wear on engine components.
An overcooled engine does not run optimally due to its inefficient combustion process, meaning it has to work harder and burn more fuel in order to generate the same amount of power compared to an engine running at its normal operating temperature. This can lead to hazardous levels of carbon monoxide being produced, which can be very dangerous in enclosed spaces.
The decreased temperature also affects the viscosity of the oil within the engine. Oil thickens in cold temperatures, making it more difficult for it to lubricate moving parts like piston rings and valves, leading to further damage caused by excessive friction and heat build-up. All these problems are likely to cause expensive repairs or, even worse – total engine failure.
Electrical Issue With Temperature Sending Unit
Finally, an electrical issue with the temperature-sending unit could also be causing your car temperature gauge drops to cold while driving. The sending unit measures how hot or cold your engine is and sends signals back to your vehicle’s computer so that it knows how much fuel and air should be sent into the combustion chamber for optimal performance.
Suppose there is an issue with wiring or connections between these two components. In that case, they won’t be able to communicate properly, which can result in inaccurate readings on your dashboard display. You may need help from a mechanic if this is indeed what’s happening, as they’ll need access to diagnostic tools in order to identify and fix any faults effectively.
Vadný snímač teploty chladicí kapaliny
A faulty engine coolant temperature sensor is one potential cause of the temperature gauge dropping to cold. The engine coolant temperature sensor is responsible for measuring the temperature of the engine coolant as it passes through the radiator.
If the engine coolant temperature sensor is malfunctioning, it will not be able to accurately measure the temperature of the coolant, leading to inaccurate readings on your car’s dashboard.
You should check if your engine coolant temperature sensor is functioning properly by using an OBD-II scanner. If the scanner detects a fault with your sensor, you may need to replace it.
Faulty Dashboard Gauge
Another potential cause is a faulty engine temperature gauge itself. The gauge measures how hot or cold your engine is running and displays this information on your car’s instrument panel. If there is an issue with your engine temperature gauge, then it could lead to inaccurate readings and cause your car’s temperature gauge to drop while driving. In this case, you should check if all of the wiring connections are secure and free from any corrosion or damage.
You should also check if any fuses or relays associated with the engine temperature gauge have blown out or disconnected from their socket. If all else fails, then you may need to replace your entire engine temperature gauge assembly with a new one in order for it to start functioning properly once again.
With most other causes, certain signs and symptoms will alert you to a potential problem. For example, your car might feel sluggish and will barely blow any air from its vents. If you don’t notice any of these signs, then chances are that the gauge is broken.
A Stuck Cooling Fan Array
Finally, a stuck cooling fan array could be one possible cause of the temperature gauge dropping to cold. The fans push air over the radiator and coolant lines in order to keep your engine running at an optimal temperature.
If these fans become stuck, meaning they don’t stop working, then they will constantly push air over the radiator even when it isn’t needed. This can decrease the coolant temperature, leading to your car’s temperature gauge dropping while driving.
If this is the case, you may need to replace your cooling fan array, so it operates correctly again. Additionally, if there are any issues with the fan’s wiring or connections, you may need to repair these in order for your car’s temperature gauge to start functioning properly again.
Can I Drive With a Low Engine Temperature?
Running an engine below its optimal operating temperature can have devastating effects in the long run. Without enough heat to properly expand the components, their fit with respect to each other can be compromised, resulting in significant internal engine wear. This can lead to poor fuel economy, as more energy is spent on compensating for the lack of combustion efficiency caused by the cool temperatures.
These temperatures also affect the catalytic converter, causing raw fuel to enter it and eventually damage it significantly. Your vehicle’s performance may also suffer due to the lack of heat available for proper combustion, as there will be less pressure on the pistons from expanding gases.
Furthermore, running an engine at lower than optimal temperatures can cause accelerated wear and tear on rubber parts throughout the car, such as hoses and seals. This is because these types of parts are designed to function at a certain temperature range and rely on proper expansion in order to do so.
They can become brittle and fail prematurely when exposed to cooler temperatures due to insufficient lubrication or heat-induced friction.
Additionally, since coolant helps keep many metal components from corroding or rusting over time, an inadequate coolant level combined with low operating temperatures can cause rapid corrosion or rust formation on metal surfaces within your vehicle’s engine bay – a costly repair that could have been avoided with proper maintenance.
Click here if you think you might have the opposite problem; having the gauge stuck at hot without the car overheating.
Proč investovat do čističky vzduchu?
Suppose your car’s temperature gauge is dropping to cold while driving. In that case, there could be a simple issue with the dashboard gauge not showing the correct temperature or a more serious one with the actual engine temperature. To determine the cause, you should check or have checked your car’s thermostat, fan array, temperature sensor, and temperature-sending unit.
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