I have a 2014 Durango Limited with a V6 and 180,000 miles. The radiator fan runs at high speed, even in the winter with the AC off, and is very loud when it is on. I replaced the thermostat, but this did not resolve the issue. I have checked both the low speed radiator fan relay and the high speeed radiator fan relay by applying 12V and testing for continuity. Both relays appear to be in working order. What else could be causing this issue?
Radiator Fan Runs at High Speed
tfresquez
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OK, I got the scanner. I actually bought an Innova Car Scan 5610.
The fan switches to high speed when the coolant temp is roughly 230 degrees. From what I have researched, it appears that the fan is supposed to kick into high speed at 230 degrees and it sometimes goes into high speed sooner as I understand there is some predictive feature that switches the fan to high speed earlier if it predicts the temp will go above 230 degrees.
When the scanner was reading a coolant temp of 217 degrees, I pointed my IR thermometer to the thermostat housing and radiator hose and read a temperature of 167 degrees. I don't know how close these readings should be to one another. It seems like 50 degrees is a pretty large spread between what the scanner is reading and what the IR thermometer is reading. Does this seem correct?
If not, I suppose the issue could be that the coolant temp sensor is bad and is telling the PCM that the coolant is hotter than it actually is. Otherwise, I suppose there is a chance the PCM itself could be faulty.
The app that my scanner connects to provides a list of probable maintenance items based upon vehicle mileage. One maintenance item listed is reprogramming the PCM. I suppose the dealer would need to do this. Any thoughts on whether this could be causing the issue? I am also having an extended crank issue. Any thoughts on whether this could be related to the PCM as well?
The fan switches to high speed when the coolant temp is roughly 230 degrees. From what I have researched, it appears that the fan is supposed to kick into high speed at 230 degrees and it sometimes goes into high speed sooner as I understand there is some predictive feature that switches the fan to high speed earlier if it predicts the temp will go above 230 degrees.
When the scanner was reading a coolant temp of 217 degrees, I pointed my IR thermometer to the thermostat housing and radiator hose and read a temperature of 167 degrees. I don't know how close these readings should be to one another. It seems like 50 degrees is a pretty large spread between what the scanner is reading and what the IR thermometer is reading. Does this seem correct?
If not, I suppose the issue could be that the coolant temp sensor is bad and is telling the PCM that the coolant is hotter than it actually is. Otherwise, I suppose there is a chance the PCM itself could be faulty.
The app that my scanner connects to provides a list of probable maintenance items based upon vehicle mileage. One maintenance item listed is reprogramming the PCM. I suppose the dealer would need to do this. Any thoughts on whether this could be causing the issue? I am also having an extended crank issue. Any thoughts on whether this could be related to the PCM as well?
Extended crank is usually fuel pump related.
I don't have my tune for my 2017 GT on hand at the moment but this is the fan settings for a 2017 Challenger SXT which is IIRC the same setpoints.
![Image]()
If you have an OBD scanner, set it up to monitor temperatures like I did. As you can see on cool days my 2017 GT hovers around 190F (the spikes are shortly after a WOT run). That should let you know if you are having cooling issues. If you ECT is higher than your EOT then it could be a faulty sensor.
www.dodgedurango.net
If you have an OBD scanner, set it up to monitor temperatures like I did. As you can see on cool days my 2017 GT hovers around 190F (the spikes are shortly after a WOT run). That should let you know if you are having cooling issues. If you ECT is higher than your EOT then it could be a faulty sensor.
2014 Durango Limited V6 Overheating
Here's what's happening. Tuesday night noticed lots of coolant under the Durango. Take it to my mechanic Wednesday they tell me the radiator was coming apart at the seams and needs to be replaced. Thursday I pick up the Durango with new radiator and everything seemed fine (didn't have to drive...
www.dodgedurango.net
Thanks for the input. When the fan kicks into high speed, the transmission temp is around 185 degrees. It appears normal transmission temp is between 175 and 220, so that doses not appear to be unusually high.
Did you map out all the temps? Just focusing on coolant temp and watching it rise does not give a complete picture. As for extended crank, 2014s had a TSB which calls out a cam sensor replacement based on the sensor SN#.
When the fan goes to high speed, the coolant temp is between 227 and 231, the oil temp is around 208 and the transmission is around 182. It appears these oil and transmission temps are normal, but the coolant temp appears to be on the high side. I would think the oil temp should be a little higher than the coolant temp, or at least closer to it. This leads me to believe that the coolant sensor may be showing a higher temp than the actual temp.
I would replace the coolant sensor, but it is low on the driver's side where it is very congested with other lines, and I can't figure out how to get a tool on it to remove it.
I would replace the coolant sensor, but it is low on the driver's side where it is very congested with other lines, and I can't figure out how to get a tool on it to remove it.
Per my previous post, would it be normal for the coolant temp to be higher than the oil temp? If not, would this be indicative that the coolant temp sensor may be bad? Otherwise, what other things may cause the coolant temp to be higher than the oil temp?
Coolant temp will initially read higher than oil temp. Below is a screenshot of my log I posted in a link earlier. Average oil temp eventually reads slightly higher than coolant temp but the coolant temp does spike. BTW the log is taken over 1 hour with mostly highway driving.
![Image]()
I am losing my mind over this issue. I took the vehicle to the mechanic for the third time. Of course the fan does not go on high when they drive it, but it goes on high every single day for me. Even though he could not replicate the issue, he suggested that the issue could be caused by a blockage in the radiator.
I read that one way to check for a blockage is to measure the difference in temperature between the upper and lower radiator hoses. So this is what I did. But I am not sure how to interpret the results.
When the fan kicked into high speed while I was driving uphill at around 25-30 mph, I stopped the vehicle and took temperature readings on the upper and lower radiator hoses with an infrared thermometer for about 3 minutes. The upper hose was at 136 Degrees and the lower hose was at 73 degrees ( a 63 degree difference). This seems to make sense since the fan running on high speed would be cooling. After the vehicle had idled for about 5 minutes and the fan kicked back down to normal speed, the upper hose was at 165 degrees and the lower hose was at 150 degrees ( a 15 degree difference). This also seems to make sense since the fan was off so the temps should be closer.
Does this information provide any insights to anyone?
I read that one way to check for a blockage is to measure the difference in temperature between the upper and lower radiator hoses. So this is what I did. But I am not sure how to interpret the results.
When the fan kicked into high speed while I was driving uphill at around 25-30 mph, I stopped the vehicle and took temperature readings on the upper and lower radiator hoses with an infrared thermometer for about 3 minutes. The upper hose was at 136 Degrees and the lower hose was at 73 degrees ( a 63 degree difference). This seems to make sense since the fan running on high speed would be cooling. After the vehicle had idled for about 5 minutes and the fan kicked back down to normal speed, the upper hose was at 165 degrees and the lower hose was at 150 degrees ( a 15 degree difference). This also seems to make sense since the fan was off so the temps should be closer.
Does this information provide any insights to anyone?
I took the vehicle to the shop for the third time. They installed a factory thermostat, which made no difference. They ruled out the coolant temperature sensor as the issue by using an IR thermometer to read the temperature on the cylinder heads and comparing this with the reading from the coolant temperature sensor, which were in agreement. They checked for exhaust gasses in the coolant, but found none. I replaced the radiator cap, and the water pump was recently replaced. They suggested that the radiator could have a partial blockage and recommended replacing the radiator.
I took the vehicle to a radiator shop to have them evaluate the radiator. Based upon their observations, they do not believe the radiator has a blockage, and they did not identify any cold spots on the radiator. They also made sure that all air was purged from the system. However, they did observe that the pressure in the cooling system very high at around 35 psi. This led them to believe that the issue is a result of a bad head gasket. However, when they rechecked the pressure in the system the next day, it was normal.
So now I am even more confused. If there are no exhaust gasses in the coolant, indicating there is no leak from the heads, what would cause the pressure in the cooling system to be high one day and normal the next day? The engine has never overheated, and I have read that issues with the heads or head gaskets on Pentastar engines, without damage due to overheating, are very rare.
Since the coolant temperature sensor appears to be fine, it seems that the engine is just running slightly hot for some reason. The temp gauge never goes above the white middle tick mark. Perhaps it would be overheating if I did not have the heavy duty fan which keeps the temp down.
I took the vehicle to a radiator shop to have them evaluate the radiator. Based upon their observations, they do not believe the radiator has a blockage, and they did not identify any cold spots on the radiator. They also made sure that all air was purged from the system. However, they did observe that the pressure in the cooling system very high at around 35 psi. This led them to believe that the issue is a result of a bad head gasket. However, when they rechecked the pressure in the system the next day, it was normal.
So now I am even more confused. If there are no exhaust gasses in the coolant, indicating there is no leak from the heads, what would cause the pressure in the cooling system to be high one day and normal the next day? The engine has never overheated, and I have read that issues with the heads or head gaskets on Pentastar engines, without damage due to overheating, are very rare.
Since the coolant temperature sensor appears to be fine, it seems that the engine is just running slightly hot for some reason. The temp gauge never goes above the white middle tick mark. Perhaps it would be overheating if I did not have the heavy duty fan which keeps the temp down.
Yes, it does happen with the A/C completely off.
The mechanic noted that the cooling fan runs at medium speed when the A/C high side pressure reaches 290 psi. The cooling fan decreases to 20% power when the A/C high side pressure drops to 250 psi. Then high side pressure maintains between 230-280 psi at idle. When he drove it on the freeway, the A/C high side pressure maintained between 110-115 psi.
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Did you replace the fan? If so did that fix the issue?
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@DeaconBlue I have a similar issue with the fan running at high speed (loud and vibrates the car) but it's resolved by turning off the AC/HVAC system. The cooling fan immediately turns off (or at least slows down to normal speed) when I switch off the climate control from within the cabin. Do you know what I could possibly do to fix this fan from going crazy whenever the HVAC system is on? For context, I did replace the AC condenser and trans cooler recently. Thermostat and coolant temp sensor are fairly new too (maybe 6 months old) but the issue seemed to start right after the AC condenser and trans cooler were replaced a few weeks ago.
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Hi @tomk my cooling fan slows down to normal speed when I turn off my A/C climate control.
What could possibly be the issue? Low A/C pressure?
I recently swapped out my A/C condenser due to a freon leak and noticed the loud fan almost immediately after.
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I had the same issue replace a thermostat no luck. Then I went to Dodge got original one. That solved the issue. They open up at different degrees.
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Had the same issue replace a thermostat no luck. Then someone told me to get one from Dodge which I did and that fix the issue. The issue with aftermarket ones they open up at different temperatures.
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