Engine temperature fluctuating I would still lean towards an air problem. Nov 30, 2023 · I've read several post on problems with the temp. waiting in a car line a noticed me engine gauge was almost spiked. 6 engine is a chore to properly remove all of the air from after servicing. Sep 24, 2023 · Your vehicle’s temperature gauge, located on the instrument panel, shows the current operating temperature of the engine. Any ideas??? Mar 31, 2021 · While driving 2015 traverse the temp gauge has started jumping around a lot. This is because a car in motion receives external airflow to cool the engine down. Fluctuations in the temperature gauge may indicate a problem with the engine’s cooling system, which could lead to overheating and serious damage to the engine if not addressed promptly. Feb 28, 2011 · I have a 2006 2500HD LLY It is new to me and I have noticed when driving around the engine temp gauge fluctuates between 180 mark and just under 210 mark. Feb 6, 2023 · Why Does Car Temperature Gauge Goes Up and Down? If a car’s temperature gauge goes up and down, it could indicate a problem with the cooling system or a malfunctioning temperature sensor. No codes, no overheating issues before this. So I plugged her in to my ODB-II scanner, and the engine temperature it is reading is fluctuating between 180-190, going up and down and up and down, never going above. Apr 20, 2022 · Dropped to 5th and temp dropped right back down. One common cause is a defective thermostat, a component that is inexpensive and easy to replace. The temperature gauge, if you want to make sure that the engine’s temperature is just fine and that the gauge is working well, should only be somewhere close to the middle of the gauge and may go up and down in small increments. Dec 25, 2019 · The water temp gauge now sits behind a computer nanny (software) that lies. Set the ignition switch to ON without the engine running. I drained both the radiator and the engine block and re-filled with the correct 50/50 mix and now the temperature never goes above 100C setting in traffic for along time and 80C constant on the highway. It could be due to a bad thermostat, coolant temperature sensor, water pump, radiator fan, or temperature gauge. It will run at the middle 210 mark then instantly drop to the 170-180 area, and then a few seconds later back up to 210. Assumed faulty thermostat so have replaced with new housing and thermostat, new stat only had 1 temp sensor whereas original had 2 but was told this is new updated thermostat housing to be Apr 24, 2019 · You won't see these normal temperature fluctuations on the needle of the analog gauge, except for the sitting with the engine idling and not moving. Car was always at 90 C when driving at operating temps. Sep 20, 2020 · 2020 GLA250 with 5500 KM. Nov 20, 2021 · Engine temperature on the gauge fluctuates and mostly runs cool. Is this a sign of a faulty thermostat? Got a hold of a temp gun. Oct 22, 2016 · [Solved] Erratic Temperature Needle The story: When I first got the car, I didn't have any issues with the temperature reading in the car. An engine is operating normally when the needle points at the center or near the center of the gauge. just 2 weeks ago I found the hot air from the 2 center air vent after I press the accelarator hard. Mar 27, 2021 · Today on a 400 mile highway run, I noticed the coolant temperature gage of my 2020 gla 250 2wd that usually is steady on approx. I no longer trust anything that is on the drivers display. When your truck reaches 190 the thermostat is opening and shooting cold water/anitfreeze into the motor and cools it down very fast hence the fluctuating then once it reaches 160 it closes back to allow the motor to warm back up then the process repeats itself my truck does the same thing and If your car temperature gauge shows the temperature going up and down and fluctuating there are a lot of possibilities that can cause this issue and problems May 8, 2018 · I drove about 15 miles. On a digital reader mine is generally at 184 degrees A/C on and normal traffic. It happens at part throttle with a slight load. Jan 15, 2022 · 2015 - 2020 Ford F150 - Fluctuating Temperature Gauge Issues - I have a 2016 F150 3. the May 8, 2018 · It continues surging up through 6000 rpm. Don’t worry if the needle does not exactly sit in the middle of the gauge. i checked the reservoir and it was at the max line. It’s not on the tstat housing. '01 ECSB 4x4, '04 6. Jun 30, 2014 · My temp is always like that, BUT every night I drive on a highway downhill, letting the car coast down at about 65-70 mph and the temp drops to around 70, so I guess the combination of high speed air through the radiator plus lower heat being put out by the engine by not stepping on the gas leads to lower water/engine temperatures Dec 26, 2019 · Basically for all the fluctuations on the gauge the temperature is steadily between 106 and 109 deg Celsius. Feb 5, 2017 · Engine Temperature fluctuation Jump to Latest 1. Jan 12, 2016 · I recently put in a new alternator. Pull over, check AF-OK, serpentine & water pump; no issues. It should go to 180 and stay there or gradually creep up or down. May 13, 2018 · At 70 mph, engine coolant temp was slowly bouncing between 223F and 243F. Turn off heat, temperature begins to May 15, 2021 · After a minute or two the temp reading came back, check engine and temp light went off, and she came out of limp mode. 2007. Ignitrous · Registered. When the engine reaches this range, the thermostat opens up and allows coolant in to cool the engine and keep temperatures within optimum levels. Feb 15, 2006 · m temp gauge was goin from the middle bar to the 2nd highest bar while i was driving. Aug 17, 2015 · 06, 3. it's about 20 seconds. Once it made it down to the negative numbers the lights came back on and it went back into limp mode. When a thermostat is functioning correctly, it only allows either warm or cool coolant to enter the engine, thus regulating the overall temperature of the car engine. It will begin to open at one temperature, and open slowly, depending on temperature until it reaches 100% open at a higher temp. Oct 15, 2011 · Fluctuating temperature gauge. Stop engine, connect the scan tool and select appropriate model year and engine option. My coolant temp stays between 199-203. Apr 11, 2022 · On my XF I noticed that the engine temperature guage only reaches to 25% after around 20 mins of highway driving and after that fluctuates between 25% and 50%. The oil temp on mine can vary a bunch when the car is run hard. Any ideas on why it would have all of sudden Mar 16, 2016 · MB had my car for the 3rd day now, got a phone call telling me it's two sensors sending faulty readings that's what was making the temp to fluctuating from 40 to 80 every time it changed gear. So normal this evening and way off in the morning? Will take it for long drive at weekend to monitor the engine temp. Feb 6, 2024 · Where should my temperature gauge sit? Normal engine temperature The ideal engine temperature should be somewhere between 195 and 220 degrees. Fluctuation had nothing to do with uphill or downhill engine loads. When i got it home i opened the hood and the fan was going full blast. It goes on and of with a recall they need to fix (waiting on parts) anyways as I'm driving along. Both aftermarket thermostats were Motorrad from different parts stores. Coolant Issues. 7 liter with 60Kmy temp gauge is fluctuating! It will move to the far right into the red and then drop down to normal temp a few seconds later. When you turn on the heat, you're just blowing air across the heater core. If the temperature gauge fluctuates alongside the ODBII readings, be prepared for a set of potential issues. Oct 11, 2017 · A constant voltage would mean that sensor or wiring is bad. Air pocket will mess up the sensor reading. May 3, 2023 · If you're experiencing coolant temperature fluctuations (e. The gauge normally stays a few ticks above half when idling for extended times and right at half cruising on the hwy. After the bleed process, let the engine idle and watch for any fluctuations in temperature. The temp fluctuated from as high as 175f down to -24f. Once running, your engine can reach temperatures up to 220 degrees Fahrenheit! 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. Temp at midrange-normal- EPC and warning light off. The new t-stat is a factory 216 degree. This includes radiator, hoses, hose clamps, and thermostat. Aug 8, 2004 · 1983 - 2012 Ranger & B-Series - 4. gauge fluctuating more than normal, but haven't really found a definitive answer to resolve the issue. 8. What could be the cause of this issue. Truck idles fine, sounds fine, accelerates fine! Thoughts? Sent from AutoGuide. It sure SOUNDS like a bad engine thermostat. May 8, 2013 · I also noticed that the coolant temp gauge needle only goes past the 1/2 way mark on the coolant temp gauge only once after the thermostat initially opens on a cold start warm up, after that the coolant temp gauge stays on the 1/2 way mark on the coolant temp gauge and fluctuates about a 1/16th of an inch below the 1/2 way mark on the coolant Aug 12, 2020 · So at that one spot the temp is going up and down. 4. Thermostat was failing. Do this until the temperature stops fluctuating. 5 3500 MegaCab SLT SRW 4x4 6. BANGARANG. Replace Temperature Gauge This is simply because the coolant is constantly being released into the engine, which causes the temperature to drop rather than climb up. Driving at 80km/h, car was warmed up (been driving for about 25 minutes). So today I bought one of those laster thermometers. Any ideas on how to get an air We would like to show you a description here but the site won’t allow us. I?ve had the thermostat, water pump, temperature sensor all replaced, but keep having the same issue. I pulled over to the side of the road and checked the engine coolant. My coolant level regulated and after the first drive the temp started fluctuating from normal temp to just over 210. I have flushed/burped coolant, changed thermostat, temp sensor guage with no resolution. Jan 10, 2011 · Modular V8 (4. Start date Oct 15, 2011; JohnS. Regular checks, prompt repairs, and an understanding of what can cause temperature fluctuations are the keys to keeping your car running smoothly. ) I've had my car off the road for a couple of months and I've just got it running and going again, however, the temperature gauge is fluctuating a lot so sometimes it'll be at the normal Use your IR temp gauge and read the hose temp of the heater hoses, into and out of the core. The engine has 107 hrs on it and just had a 100 hour maintenance performed as of September 2017. Upon removing the hose for the valve, I discovered the water was a nasty sandy mess. Stock everything. Today, engine temperature started moving sort of erractically. 5K views 3 replies 3 participants last post by abbott013 Feb 5, 2017 Dec 28, 2021 · I noticed that for last 4-6 weeks my 2017 Chevy Colorado's temperature gauge is erratic showing its overheating (230° to 250°) after driving for 10-/+ minutes then it returns back normal level (210°) and then goes back "overheat" then back to normal this repeats several times. This ranges from 180°F to about 200°F. Feb 15, 2022 · This is a sign that the thermostat is not reading the engine’s temperature correctly and releasing the coolant at the wrong times. 1 2. 3 hr drive home & watching temp gauge: occasional brief creep into red zone with Oct 30, 2013 · Air in the system will cause the temp to go up and down quickly. Mar 22, 2021 · My 2017 3. Jan 20, 2022 · So I have the 2015 JGC Limited and recently have been having some issues with the temp gage fluctuating all over the place from where it would normally sit around 1/4 of the way up to all the way to hot within a matter of seconds which would prompt me that my engine coolant is overheating then would immediately go back down. So far no temp fluctuations, ac works both hot and cold, the car comes to a operating temp pretty quickly but the radiator is full, so is the expansion tank, and the block is also filled. Dec 28, 2023 · Loosen bleed valves, rev the engine, and continue this process until temperature fluctuations stop. Took it to shop , they say pump assembly which holds thermostat and sensor. It will start out from initial start cold and climb in temp, Jan 25, 2020 · (This was also posted in the electronics as I'm not too sure whether it's engine related or the electronics. Typically I've found that the temperature spikes are when there are moments when the sensor isn't in contact with the coolant. When the radiator is positioned at the higher point in the system, the air will escape into the ra Jul 5, 2024 · In case you have a faulty gauge, you’re lucky because the engine hasn’t suffered any potential damage due to temperature fluctuation and neither have any parts of the cooling system. Finish drive. Jan 27, 2020 · Hence a fluctuating gauge is reason for concern, as it points to possible faults elsewhere. $2000 estimate. Located within the engine, this sensor may become contaminated, damaged, or Jun 12, 2021 · The engine temperature rises when the required amount of coolant is unavailable. A bad radiator cap can also be the reason why the car temperature gauge goes up and down while driving. It is important to have the issue diagnosed and repaired promptly, as a faulty cooling system can lead to engine overheating and potential damage. For more specific insight, scroll down to the list of the main causes of the engine temp gauge fluctuating at idle below. I noticed that the temperature gauge was fluctuating up and down. I replaced the temp sender, coolant tank cap, and have disconnected the EGR plug with no changes. 0 Supercharged. Beyond that, what you are observing could be totally normal. 3 months no issues. May 26, 2023 · If these hoses become blocked or kinked, they can restrict the flow of coolant, leading to a potential increase in engine temperature. Continue topping off the coolant as the levels drop. You don't circulate any additional fluid anywhere by turning on the heat. I was driving my Dodge Ram 1500 on the highway. I concluded, this was a normal operating condition of the engine and was not a problem. The wife said she was parked for about 15 minutes and when she started it up the coolant fan was Jun 25, 2021 · Hey all, newbie here. More so, you can also blame the radiator Jun 4, 2023 · Temp Gauge Fluctuates At Idle- Main Causes. The temperature of the water coming in is 45F to 50F. Set air conditioner (if equipped) and blower fan to OFF. the #10 tick mark after warm-up was fluctuating between the #7 and #11 tick mark at a steady speed of 70 mph and 50 f outside temp. Since Day 1 it was common for the coolant temp to rise above 200 at times, but quickly return to around 190. Overheating Mar 27, 2022 · The temperature gauge goes up as the engine heats up, and continues to rise when the engine is under a lot of strain, like going uphill. The sensor relays engine temperature data to the ECU. I just purchased a 2014 Sahara JKU. i just changed the radiator cap, hope this works. Then when I drive it on the interstate, the temp gauge appears normal and the engine temp goes to the middle part of Feb 4, 2024 · Since this was a good time to aslo replace reservoir tank and reinstall a oem radiator this completed a refurbished cooling system as well as lubrication system, however I have had coolant temp gauge fluctuates somewhere at 180 degrees F to to 210 degrees F, system has been bleed out air possibly however the gauge fluctuations has me spent out Nov 10, 2014 · the temp does rise as you stop and then get moving again. Have a professional mechanic inspect and diagnose the issue. Looking at temps in diagnostic mode on convers+ it’s giving never more than 75degC, often 60-65 with steady driving. If your car temperature gauge fluctuates at idle, something bad may have happened to the components inside the cooling system, such as the radiator fan, head gasket, or water pump. Put back on and filled up radiator with coolant I had. . Started driving home and the temp gauge would move from normal to hot. If the thermostat is bad, it may open and close continuously and cause the coolant temperature to fluctuate up and down. Ran great for about a week, but now the coolant temp keeps fluctuating between 1/2 and 3/4, occasionally high enough to start yelling at me. Temp before the new tstat was around 208. What you need to know is that a temperature gauge that’s fluctuating erratically isn’t normal. Feb 25, 2020 · The engine will gain temp faster than the t-stat opens fully and you see the indicated temp rise higher than "normal" while everything is settling into the full temp operation. At idle temperature seems to be fine but as soon as I give it throttle the temperature gauge goes up, cutting power and throttle response. Mostly just sticking at 108 deg Celsius even when the gauge is moving wildly. 4. I finally figured it out, months later. Jan 31, 2014 · If you hold the odometer reset button on startup, after engine is running it should enter "test mode". Fortunately it would cool back down to 210 but the fluctuating is not something I have seen on my truck before. Radiator was about 45C all over except very top near where hose from engine goes in which was 65C. At 60 mph, engine coolant temp was slowly 221F and 238F. I always set it on auto 23C". Coolant temp fluctuation is completely normal and will vary with engine load and air flow across the radiator. Now my EPC light is on, check engine light on. If the heat is then re-activated, engine temperature drops. 5, 4x4, 170k Last week, i replaced my valve cover, water pump, fan clutch, intake manifold gaskets, and TB gasket and have since had erratic coolant temp readings. If it got to 240 I'd start to get worried but so far, even towing over 4 tons the operating temp is between about 203 and 225. The needle will rise from the N on normal to just above the L then drop back to the N. Diagnosing the exact cause of your engine’s fluctuating temperatures can feel like detective work. As the engine RPM is picking up the temperature starts picking up going to 170F and back down to 135+, back up and back down. 6 which just started late last week. The PCM enters inferred mode when it sees something that can't normally will be correct and send out faulty temp readings so the engine can at least run. I suspect the AGS will open briefly at higher speeds to reduce coolant temperatures and then close again. Jul 17, 2022 · Hi Started yesterday noticed whilst driving my 18 plate fiesta mk8 Zetec 1. It works by reading the coolant temperature from the sensor located in the cooling system. I say no, engine is fine and so is thermo and pump. I went thru a period when the engine was only running at 180. 2012 Apr 25, 2025 · A car temperature gauge goes up and down because the engine’s coolant temperature is high. Car takes awhile to warm up and when it does it fluctuates all the way to the red and down to cold. Release button & press repeatedly to scroll through readout functions (rpm & temp for example) stop on temp and drive to see if reported temp to computer matches gauge. When the needle on the gauge points to the center or near the center, the engine is working normally. Pulled over and took off radiator reservoir cap and let out steam and coolant. A fluctuation as described once up to operating temperature says to me that there is something wrong although not sure it is going to be a problem with the engine or cooling system. 5L Ecoboost that keeps having issues with fluctuating engine temp. I’m fine with the temp. Then leaving work this evening before I started the car, engine temp was 8 and external temperature was 7. If it's warmed up and all, it shouldn't drop below the normal 205-215 range. Big changes like that aren't normal. Got myself a scanner and monitored temp. Maybe not though. I sensed something was wrong, but I trusted that lying gauge. 0 with a fluctuating coolant gauge. By addressing these signs promptly and seeking professional assistance, you can prevent further complications, ensure safety on the road, and avoid costly repairs. I have a 2020 Colorado with the 2. During my recent ride the engine temp was fluctuationg between 79ºC and 83ºC. 0T, checked the coolant level and it was below min, couldn't even see the coolant fluid level, so I rush to buy some coolant fluid to top it off, now the coolant level drops again, nowhere near the min level when engine is cold, and can't Oct 16, 2010 · Any number of things could cause changes in temperature fluctuation, at no time should the temp gauge be used as the sole diagnostic tool. Apr 1, 2015 · HT look at the performance page - gauge one. It fluctuates like this continuously. 0L Temperature Gauge Fluctuation / Thumping in Cooling System - I've seen a few posts recently regarding temperature gauge fluctuation and/or a thumping in the cooling system of the 4. When a thermostat is faulty, two things may happen. Jump to Latest I'd be worried about the condition of the engine getting that hot that many times. This can damage the engine parts as they expand and contract due to the fluctuations in the engine’s temperature. My questions are Nov 20, 2024 · During my recent "think this is my last ride for 2024, again" ride, I noticed the engine temp fluctuating. After driving a few miles without the heat/ac on, my temperature gauge drops to the 1/4 mark. Symptoms: Warm / hot weather: gets to operating temperature quickly and stays there consistently even on 90+ degree days. Dec 30, 2021 · Then I started to read more about the active grill shutters (AGS) that open when the engine coolant temp gets a certain predetermined temperature. Coolant is full. This was with an outside temp of about 106. Most accurate way is to check the sensor's resistance with an ohm meter. Jul 29, 2023 · Fluctuating temperature gauge readings may point to a failing thermostat, malfunctioning temperature sensor, faulty radiator cap, or air pockets in the cooling system. 6L Summit (with towing package) with 131,000kms. After getting the car back, the engine coolant temp gauge would basically fluctuate between normal operating temp and 5/8ths (running hot). So I look at the temp gauge and it's The thermostat is responsible for regulating the engine temperature and keeps it at the optimum temperature. The engine stays at this low temp (and barely fluctuates, if at all) until heat’s fan is turned to lowest setting or off, at which point the engine’s temperature returns to img #1 after 60 to 120 seconds. The hose from the engine to the heater requires the water pump to push the water through the core. The coolant stays at the low end of the above ranges for a couple of minutes and then swings up and back down in the course of 20 seconds or so. That should confirm the issue. Hard throttle does not make the problem worse. Sent from my iPhone using Tapatalk Conclusion: Importance of a Stable Temperature Gauge. Typically my truck runs right at 210 but today started increasing to 230-240. May 6, 2025 · The coolant stops flowing when there are faulty radiator fans, resulting in a fluctuating temperature gauge. Temperature readings go from idle at 215 to a very hot 245-250 once I get moving. Thermostat housing: 140 Intake manifold just below t-stat housing: 160 Side of head between exhaust ports: 220 exhaust manifold: 410 What do you guys think? Edited by Big6ft6 on 01-01-10 Jun 27, 2004 · The one on the rad is the fan switch, I believe. This is just around town driving, 5 miles to work and Jan 21, 2024 · Fluctuations in the temperature gauge, steam or smoke from the engine, and coolant leaks are all indications that your engine may be experiencing temperature-related issues. Dec 28, 2022 · Today I decided to start my car and let it run until the temperature gauge reaches half way. If they both read colder then the engine there is a problem. 0L LQ4 Jul 11, 2019 · First noticed 3 weeks ago the engine temperature fluctuating and the fan getting faster on my 2017 Q50 3. I noticed it ONLY happens when I step on the gas (ex. The sender is located on the water outlet pipe for newer engines. Some users report that these fluctuations are normal, especially with varying engine loads. Very hot. The temp sensor should be on upper hose neck on the engine. I put a new radiator and water pump when I did the swap. How To Fix Engine Temperature Fluctuations? You might wonder what to do if my engine temperature goes up and down Feb 6, 2011 · There isnt a problem with your trucks its just these trucks have extremely effiecient cooling systems. Feb 27, 2023 · Start the engine and turn the heat on high with the fan on low. I had to replace the heater control valve, as it had frozen shut. 6L Auto, 83K miles. While it must not be encouraged, some people mix a high quantity of water with the coolant. Once the strain on the engine has passed, it will start to cool off and go back to its normal operating temperature. Faulty Temperature Sensor Cause. Other causes of a fluctuating temperature gauge are a failing radiator fan, insufficient coolant level and a leaking cylinder head gasket. 6 Ram temperature guage cluster fluctuates from 200 degrees to 260 degrees. Dec 11, 2022 · The sensor is designed to keep the temperature gauge in the normal range, even if the engine coolant temperature fluctuates. If the radiator cap is weak, it is unable to regulate the temperature of the engine coolant. This causes the car temperature gauge to show a higher reading as the increased water level cannot carry heat away from the engine as the coolant does. My heater core had sprung a leak and since a heater is part of a gov't safety requirement here I put a plug in both hoses and Easy Guide: Why Your Car's Temperature Gauge Moves Oct 14, 2012 · The thermostat is slow reacting and engine load will change engine temp pretty quick. How to Diagnose Fluctuating Engine Temperatures. Set the parking brake and verify the transmission is in park or neutral. Nov 18, 2008 · Drained the radiator, engine block and refilled everything with almost 8 liters of the long life toyota fluid mixed 50/50 with distilled water. The heat works very good it just takes a while. 2. If the fluctuations are quick and sporadic in nature its 90% of the time air you are building steam in the "dry" places caused by air pockets. Then it fluctuates from the C line, all the way down below the C line to the beginning of gauge like it was just started. Near home, at 40mph, engine coolant was only hitting 230F. But i could only get it to read 236 off the return pipe leaving the engine. 6L, 5. Temp never goes above the C line. The strange thing is that Now it did not fluctuate, the gauge just slowly rose to 260 and the standard warnings went off. 4L) - Engine Temperature Fluctuations - not Thermostat - I have some strange engine temperature symptoms on my 97 Expedition 4. Apr 9, 2007 · Temp fluctuates. Check it when the engine us cold. I figured I would post a few TSBs that I have run across that are applicable to this Aug 10, 2023 · Suddenly my 2015 Dodge Charger SXT wants to overheat. Normally, my bike runs a constant 81ºC while cruising along at constant speed. I've seen other guys report the same thing so I guess that sort of temp fluctuation is normal. Usually, an idle car relies completely on the cooling mechanism. Was hard to get a good readings as alot of stuff in the way but pretty confident everywhere was 45C. This will leave your engine’s temperature fluctuating between hot and cold while you drive your automobile. Started it back up and temp was normal. In this weather, the thermostat should be open all the time anyway. Aug 6, 2021 · But Temp fluctuation is 90% of the time one of 3 things, Radiator cap, thermostat or air in the system. Oct 16, 2021 · The 3. If different, gauge problem. Dec 14, 2023 · #3 – The Engine Temperature Fluctuates Up and Down Your thermostat regulates the flow of coolant through the cooling system and engine by opening and closing at a determined temperature . Don’t worry if the needle does not fall precisely in the center of the gauge. Is this normal? On my old Audi it used to go to 50% mark very quickly and just stayed there as long as I drive. Mar 12, 2011 · This added problem I believe contributes to heater core blockage which clears up under higher rpms (a bit better) and sometimes releases a blast of cooler hearter core antifreeze which since it immediately contacts the coolant sensor switch near the engine, causes a huge temperature fluctuation until the heater core system stablizes in temperature. It seems it only occurs when engine is completely warmed up. I If your car temperature gauge shows the temperature going up and down and fluctuating there are a lot of possibilities that can cause this issue and problems We would like to show you a description here but the site won’t allow us. Maintaining a stable engine temperature is vital to vehicle longevity and performance. This is just one sign that the thermostat is going bad. A constantly running fan is the probable reason your engine temp is low. A low coolant level can cause the engine to overheat, resulting in the car temperature gauge fluctuation. Here are other signs. Loosen up the bleed valves and rev the engine a few times to circulate the coolant. Joined Mar 9, 2006 · 550 Posts #21 · Feb 4, 2013. Aug 20, 2013 · The cooling system was full of air bubbles as well as a wrong coolant mixture. The first step is to determine if the lower radiator hose sensor is bad. Oct 14, 2012 · The thermostat is slow reacting and engine load will change engine temp pretty quick. I could watch it and over Dec 7, 2015 · You are almost correct as to the functions of the temp sensors. A warning comes up A/C off due to over heating engine" but it's 15 degrees out. Cab heat was always working well for me. this happens continuously in 5 to 10 second incrinents. It also takes a long time to warm up. In my 2010 Fusion, the thermostat begins to open at around 186 degrees, and reaches 100% open @ about 208 degrees. Nov 11, 2019 · The engine in your vehicle runs hot. Thread starter JohnS. May 31, 2016 · The engine temp on my 04 Silverado started fluctuating today. A mechanic told me it would be the engine coolant temperature sensor, another told me I had to replace my head gasket. However, during idling and/or slow traffic, during the summer and especially (for Feb 2, 2013 · That much temp swing doesn't sound right. My Banks confirms the temp change. Floor it up a hill and it will be bang in the middle, ease off or sit at 50 on a motorway through roadworks and it drops right down to nearly bottom of gauge. This happens particularly under load, like going uphill or at higher RPMs. I’ve tried to find a relief valve to purge the air but I can not find one on this 6. Got the parts late today say it's a 3 to 4 hour job as they are located at the back of the engine. 1. I did notice that when the radiator fan kicks on high, this is Feb 12, 2016 · The engine warms up to just at the C line, on the bottom of the gauge. Cold weather: takes a long time to warmup (+-10miles), even longer around town with heat on from start. This reading is taken from ECT. I Jun 13, 2011 · This is almost always due to an issue with the temp sender or its wiring. Oct 2, 2014 · The most likely cause of a temperature fluctuations is either a flauty temperature sending unit , air in cooling system or a defectective cooling fan . Just for background, before this issue my truck pretty much stayed right around 210 on the gauge Apr 15, 2022 · Consequently, it may release engine coolant when the engine doesn’t need it and failed to release the coolant when the engine does need it. Start engine after 2 minutes; back in normal zone. 8. So no more fluctuating temperature gauge. Consequently, your engine will go back and forth between being too hot and too cold. I’m just concerned with the fluctuating. Engines do not rise in temperature and immediately drop so it is likely you have air trapped in your cooling system. And I also know that the hot air should not come from the Feb 24, 2016 · Odometer is 96k miles now. Went for a small drive until needle just started moving on from operating temp. I notice that for the most part, once the engine reaches normal operating temperature, the temp gauge will fluctuate a very very tiny bit. At engine temp with heater valve open they will be real close to actual temp in the hose. Faulty Coolant Temperature Sensor. Mine will go up about 10 degrees in a good 8-10 second pull then slowly drop. I imagine it only goes up from there then back down. If the engine temperature is stable when driving at highway speed and temperature rises when idling or in traffic , the fan is the cause . Here’s a real-life example. 3. Oct 21, 2003 · A slight fluctuation is actually 100% normal. Again, if after the engine has thoroughly cooled down and you take the cap off the radiator, it needs to be 100% full. 6 speed turbo So yesterday the check engine light comes on. Nov 7, 2009 · I have a 94 ranger 4. Twice now, the temperature gauge quickly rose to 3/4 and then dropped back to normal. , bouncing between 185-200F) after replacing your thermostat, it could be due to trapped air in the system. Jan 11, 2023 · What would be causing my truck temperature to fluctuate at average operating temp when driving down the road? It fluctuates up to 4 degrees above normal operating temp; I don’t understand why it would fluctuate below normal operating temp 4 degrees when driving normally. I let it idle until it reached 260 again and checked the engine's temp with my laser temp gauge. g. Then I turn engine off , then immediately on. the thermostat was just replaced along with a head gasket repair. Dec 13, 2017 · 2 1/2 hrs into 3 hr drive in my 03 Rubi; temp gauge goes into red zone & light comes on. The sender has single wire with ¼ inch wide spade terminal and 10 mm hex head If coolant level is correct, it is not boiling over and the radiator cap works correct, the best way for home mechanic to test the sender is to replace it Engine temperature fluctuates from 220-230 down to 190 and back up. Dec 18, 2019 · I have a 2014 GC WK2 3. Installed OEM thermostat last night and climbing the hill to work 198 was highest tempin town 190. One is lack of proper pressure and the other is whether the sender is actual submerged in coolant or not. You will generally only see the phenomenon when the ambient temps are cool and usually only for the first few t-stat cycles. 1l ti-vct 26k on the clock the temp gauge didn’t hit the usual just below the centre line , carried on driving and the needle started going down nearly to the first line then would go back up and continued to do so for a 4 Sep 1, 2016 · When I was still living in San Antonio shortly after I bought my truck the coolant temp would routinely get to about 220 if I was sitting in Summer traffic with the A/C on. Mar 31, 2024 · Hi guys had problems with engine temp fluctuating depending on driving conditions (temps dropping when coasting on motorway or sitting at traffic lights. 5 4 cyl. My temperature gauge will also drop from 1/2 to 1/4 if I was to idle my car with the defrost & floor heat on. Jun 24, 2014 · 2010 5. anyone else have this problem? Oct 13, 2024 · Hello everyone, I'm experiencing rapid engine temperature changes in my 2019 Jaguar XJ50 3. Nov 16, 2011 · Engine Temp Gauge Fluctuating?? Jump to Latest 19K views 12 replies 6 participants last post by Joestsx616 Jul 15, 2020 Jan 19, 2020 · Temp gauge 1 bar down from Max. Then have someone wiggle the temp sender wiring while you're watching the temp gauge. It used to remain fairly constant with small gradual up or down movement. once the engine is warm. Apr 23, 2009 · I may have the same problem the engine temp fluctuates from 160 to 192 average driving, pulling or going 75 mph the temp rises to 192 to 203 kicking on my fan clutch also the mileage sucks really really bad(4wd), i changed thermostats, fan clutch, antifreeze have no idea what else could be but just took a trip of 200 miles pulling a 36' gooseneck with 12,000 lbs running at 60 mph and it ran The ideal engine temperature is between 195 and 220 degrees Fahrenheit. Aug 10, 2018 · The engine should be at normal operating temperature. It Should be the same. Ever since then my engine temp fluctuates from where it used to be rock steady (a tick below the half way mark) to a couple ticks above half way. How The Temperature Gauge Works Jan 13, 2015 · When the truck warms up the gauge needle will approach the C line, and then right after passing it begin to travel back down below it. when entering the freeway) or at high speeds. It does this even when I am not hauling anything. If it’s giving inaccurate readings, the radiator fan might not kick on, creating a real overheating . Dec 26, 2024 · Some people use a vacuum tool for a more efficient refill. Thanks in advance. Mar 8, 2006 · Engine Temperature Fluctuating. 0L OHV engine. There are two reasons. No check engine light. But that coolant temp has been pretty steady, see what that looks like on yours. My radiator is full of coolant. In my years as a mechanic, I’ve developed a process to make Feb 20, 2016 · The temp gauge fluctuates from normal (185-200) jumps to 250-270 than immediately back to normal. The gauge has a normal range your engine should stay within, typically around the halfway mark give or take a bit in either direction. Jun 3, 2023 · I just did an engine swap in my 2000 Silverado. The engine water temp is going to go up and down a few to almost 10°F difference between low/high in normal operation, depending on load on the engine and airflow through the radiator to cool it. I Feb 9, 2014 · 2011 Cruze 1. 7L, 68RFE w/ Mag-Hytec, XRT Pro, Diamond Eye DPF Delete, leveling kit w/ Bilstein 5100s, SnugTop Rebel shell, Insight CTS, Hell Bent Steel SBS - SOLD Feb 23, 2017 · This means that when the engine temp fluctuates within the safe range, the gauge stays put and the owners don't bother the dealership for no reason. but on a properly working Lambda (2009-2012)--- tyical traffic should not show the needle move the needle is programmed to move with higher temp swings Though if you monitor the engine temp via the OBD port you can see the actual engine temp rise (without the needle moving). Registered VIP. A malfunctioning Coolant Temperature Sensor (CTS) can significantly contribute to the Jeep temperature gauge going up and down. The dial on the side is near worthless. Air rises to the top of the cooling system and gets trapped, causing the cooling system to vapor lock. There is no signs of a blown head Aug 27, 2013 · Was out riding yesterday afternoon and noticed the engine temperature increase from the normal 160 to 170-180 and then drop to 150, before settling back to 160. From memory/ observation, the Fiesta's normal operating temp is 194°. Glad I did as on flat ground/in town empty temp was running 215 to 220. Only show this Jan 21, 2013 · The engine coolant temperature sender for gage is different from coolant temperature sensor for engine computer. Last fall I stated getting unusual coolant temp swings. The thermostat is a dynamic device in most cars. If the engine temperature rises but goes back down, the motor might be working too hard. I filled the coolant as usual. The common causes of a fluctuating temperature gauge are a faulty cooling system, a low coolant level, a bad thermostat, and a defective temperature sensor. Related Topics Nov 15, 2013 · This morning before starting the car I checked the engine temp, it said -1 and the outside temperature was +9. it makes inside the car very hot!I's never hapeened before. Mar 21, 2024 · Reasons Your Car Is Overheating Then Going Back To Normal Temperature. Jan 13, 2018 · I have only owned the truck for 4 months. Check your coolant level and leak. Can you select to monitor engine temps on your DIC? It is quite normal, based upon engine load, ambient temps, etc, for the engine temp gauge to move around some. Feb 5, 2006 · RE: Fluctuating Engine Temperature and automatic climate control other problem about my car is the Automatic climate control. Jump to Latest 21 - 36 of 36 Posts. I took the car back the next week to AAA and expressed my concerns and they replaced the radiator and thermostat again for me. Then it happens again. Jan 17, 2020 · 2014 C250, 81,xxx miles. 5. When my temp gauge was reading just below 210, here the temp readings I got on the exterior of the engine. At the 55 second mark of the video, the temperature just drops below 80 Jul 13, 2018 · If the engine is running, coolant is flowing through the heater core. com App May 9, 2013 · Recently my engine temperature gauge has been moving up and down if a short amount of time. RELATED: How to Bleed Your Cars Cooling System (9 Easy Steps) 4. It always happens after driving it, if I give it a little throttle the temp comes down. It is best to pull over and have the car inspected by a professional mechanic to identify and fix the problem before continuing to drive. The temp can lie, but if the voltage remains constant while the temp changes, than it point to that sensor or wiring being bad. I figured it was the thermostat, changed it out and still same symptoms. the fan has been running more than usual lately. Start and allow engine to reach normal operating temperatures. It did this after about 20 minutes of riding. I had the same problem with mine. Jun 22, 2015 · 2011 Ford Fiesta SE Manual Transmission 71k Miles I have an ultra gauge to monitor my instant MPGs and noticed yesterday that my engine temperature was fluctuating from 195° - 199°, with a 201° spike. Apr 13, 2022 · Car was then running fine for a couple weeks. inqeyhtkgqfydmjlkbvwxlmvwthombnkcuaitkeaoo