2011 Mini Cooper S, recent cooling fan issues, high speed cooling fan (Stage 2) comes on immediately following inserting the key and turning on ignition (Not starting engine). Engine is stone cold (Sat in my garage all night long), cooling fan stays on high speed for the entire drivetime to whatever destination I am heading, whether a 5 minute drive or longer, high speed fans remain on for approximately 5-10 minutes after engine is shut off although engine has never reached operating temperature. Had the car scanned, indicated a "Engine coolant sensor short to ground". I have replaced the thermostat housing with a Brand New Genuine Mini housing and the same issue remains. Additionally, I do get a amber, then red overheat warning on my DIC although the car does not seem to be running hot and have experienced no overheating issues. Has anyone experienced these same issues and would like to chime in on any thoughts??? Just for clarity, thermostat housing bleeder has been bleed and no air pockets are present, coolant is Genuine Mini (Blue) and is at the appropriate level in the overflow tank. Lastly, we did use the "Updated" thermostat housing with the pigtail wiring harness adapter as I had the auxiliary fan sensor in the radiator hose cast elbow from the factory. Sound like a defective thermostat housing (Coolant temp sensor issue) or an ECU/wiring problem??? Any help would be greatly appreciated!!!

 

https://www.northamericanmotoring.co...-shutdown.html

Just talked about this, low coolant and air in the system. Bleed again and fill. Check the connections at the neck of the sensors and make sure they are hook up correctly. I had heard of the oem sensor going bad, but its rare. Let us know.

 

Understood however, why would the fans kick on high speed (Stage 2) when the car was parked all night long and the engine is stone cold, nevertheless the car is not even running, only the ignition is engaged to the on position. BTW, "Genuine" thermostat housing was purchased from ECSTuning so I am hoping it is not a defective thermostat housing!!!

 

I've seen this on a Chevy Yukon; I was at a restaurant and the owner was disconnecting the battery because the fan was running at max speed even with the engine off and the key removed. I said "Hey! bring it to my shop, and I'll scan the computer." Turned out he also has a bad coolant temp sensor; $20.00 fix. Turns out the logic in the computer will run the fan at max power if is is unsure of the engine coolant temp (failsafe).

The MINI is probably set up the same way to prevent engine damage if there is no coolant temp reading to the DME. If you have a short to ground in the coolant temp sensor circuit, you need to find the short; possible causes, 1. The sensor (doubtful since changing it with the thermostat housing didn't fix it), 2. Wiring problem, (most likely in my opinion), and 3. internal short in the DME (rare.)

 

I have the same issue with my 08 Mini hatchback. I've replaced thermostat, cross pipe that leads to water pump, temp sensor, reservoir, fan, and external temp sensor and still the same problem. No matter how cold the car or temperature outside is as soon as I insert the key the fan comes on and won't turn off until 6 minutes after I turn off the vehicle. Yesterday while I was doing nothing with the Mini I merely opened the passenger door to get my camera and when I shut the door I heard the fan turn on. I installed a kill switch by inserting one wire into the slot marked fan1 relay and grounded the other wire. I turned the car on , fan kicked in, I turned on the ac and then switched the toggle to off and although I could feel the ac kicking off the darn fan still stayed on. I've tested the temp sensor, checked for leaks and all is well. I still drive the car and haven't had any loss in coolant level. I've bled the system to the point of ridiculous and nothing changes. All signs lead to a bad or faulty ECU but that's out of the question due to cost. Hopefully you can figure out what's wrong with your car and share. Good luck!!

 

@scott718 ,

RESOLUTION- although you’ve put in a new OEM coolant temp sensor, the two wires that goes to the sensor is NOT making actual contact to the sensor. What you need to do is take the two wires out of the pigtail connector that was in and directly hook it onto the sensor without the pigtail. Pay attention to the orientation to the wire but don’t worry, you won’t short out the sensor or DME if the wires are reversed. This is the only real fix that I know of since the OEM pigtail won’t work on a new sensor.

 

Just wondering if you guys got the revised pigtail connector that are needed for the new thermostat. Mini did an update to both thermostat and those connectors.

 

I ordered an OEM plug with wires last week and should be here today or tomorrow. This was my last attempt but it is good to know someone else thinks the same way.

Thank you for your input, I'll post my results in a few days.

Thanks again.

 

This^ points to an electrical problem.

Testing the sensor wires with a multimeter might reveal the problem. [GE = yellow wire, SW = black wire]

 

This very timely. I just changed the thermostat, and now the fan runs for 5-6 minutes after I shut-off the car. Is there a part # for the new plug?

 

@idickers ,

As mentioned above:

RESOLUTION- although you’ve put in a new OEM coolant temp sensor, the two wires that goes to the sensor is NOT making actual contact to the sensor. What you need to do is take the two wires out of the pigtail connector that was in and directly hook it onto the sensor without the pigtail. Pay attention to the orientation to the wire but don’t worry, you won’t short out the sensor or DME if the wires are reversed. This is the only real fix that I know of since the OEM pigtail won’t work on a new sensor.

 

At this moment , there aren’t any replacement OEM pigtail plugs available in the market.