The mechanical timing is also something that you should check, as we mentioned above. The resistance across the sensor terminals should change with the temperature according to the chart that you can find in the. The fault is most likely to be caused by the systems that the sensor is monitoring, but might even be caused by the wiring to the sensor itself. A functioning cooling system will be able to keep the coolant at a regulating temperature of between 194°F and 212°F. If the coolant temperature is too low, it will usually cause the engine to consume more fuel and produce more carbon emissions. YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle.
Overheating your engine will result in engine failure Code P0128 Common Diagnosis Mistakes Many just replace the thermostat without checking all possible causes. As a result, the engine stutters or backfires, if it runs at all. But if the thermostat is always open, then it cannot do this. Want the best online repair manual? If this is the case, the connectors will typically deteriorate and cause a poor connection. The thermostat is close during cold starts to help the engine warm up. To do this accurately, you need a scan tool, but a reading is also possible to obtain if your car a has a temperature gauge.
You will also notice the engine temperature needle dropping when driving at higher speeds along with a check engine light in the console. This is due to a leak in the seal or the thermostat open stuck. But my experience is that the thermostats result in a false positive far too often. When the thermostat does open, hot coolant should start to flow and quickly warm up the radiator hose. You have to be careful because it is hot enough that you could be burned. The thermostat is a mechanical piece with two important goals, helping the engine reaching its operating temperature as fast as possible and then keep that operating temperature stable under any driving condition. Then compare the readings to an actual temperature check with a contact thermometer or non contact infra red thermometer.
No signs of overheating, yet it failed open again. The most likely scenario is that your thermostat is not working properly. If the radiator hose heats up slowly, the thermostat is stuck open or opening prematurely and needs to be replaced. In case the Check Engine Light stays off then you may have an intermittent problem. For all intents and purposes, a P0128 code indicates the thermostat is stuck in the open condition. I can not fix it and neighther can two machanics figure it out.
Any resulting engine damage would take a period of years most likely, but the chance is there. Usually not getting hot enough in the time given, that is standard. Testing the thermostat is difficult, as it may work most of the time, but sticking intermittently. What are the symptoms of the P0128 code? The improper timing of the explosion sometimes pushes the cylinder the wrong direction or interferes with the turning of the crank. If you see this code, your thermostat is probably starting to fail! If you have a scan tool with live data, check the engine temperature when the engine is cold, it should be close to outside temperature.
If there is excessive rust and poor coolant condition this can clog up the cooling system or cause the thermostat to stick. How serious is the P0128 code? False readings somewhere in the middle will give combinations of both symptoms. The Fail-Safe thermostat is designed to lock in the full open position in the event of an overheating condition. Done smoke text checked vent valve or charchole canister and all hoses and wires. Check your coolant level first to make sure it is full before continuing to operate the vehicle.
Actually, there are two coolant temperature sensors. Check the engine temperature right at the thermostat housing. What repairs can fix the P0128 code? However, it is common for the engine to take a longer time to warm up after cold starts. The difference should not be greater than 10-15 ° C unless the sensor has a serious internal wear. If the scan tool reading does not match the thermometer reading closely, then there is an issue with the sensor side of the car. Once the motor is warm enough, the thermostat will open to allow the coolant to circulate while maintaining the required operating temperature. P0128 is not a very serious code.
If the light lit during your driving cycle then continue with the diagnostic process. In other words, there is a problem with the engine operating temperature not being reached within a certain amount of time. If the hose gets hot all of sudden like it should, then the next thing to check is the reading you are getting from the coolant temperature sensor. At first I thought that maybe the engine did have an overheating event. Make sure to flush the engine block and radiator when replacing thermostat to prevent deposits from getting stuck in the new thermostat. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There's a problem with the car's emissions system.
If the trouble code showed up after a recent coolant flush or coolant leak refill, try bleeding air out of the system. However, if not repaired and the vehicle is used over a long period of time, there is a small chance that water contamination of the oil could cause deterioration and engine damage. Now that is customer service. Using tap water instead of distilled water will also cause problems in the long run. If the coolant level is low, fill the coolant system and check for leaks. Without a scan tool, the engine temperature sensor can be tested with an ohmmeter. If the ohm reading is not changing with the temperature, replace the coolant temperature sensor or repair the wiring for the sensor if it is damaged.