Hi - I am having a problem with my 2009 Base Mini.

The radiator fan runs for about 10 minutes after I shut the car off - facts are:
* cold weather - 15F to 50F
* engine is lukewarm to the touch after a 50-minute ride
* coolant level in tank is fine
* have replaced temperature sensor
* during sensor replacement, coolant was right at the level of the threads
* pretty much no cabin heat to speak of
* if I start the car and run it for 10 seconds, the fan still runs
* no visible leaks at all

On occasion, the car has behaved normally for one or two trips. But now it is misbehaving constantly and as temperatures in Ohio begin to dip further, I would like to have some cabin heat and also have the engine operating at the correct temperature. Also, I tested the original sensor and it behaves generally as expected: low impedance at high temperature and about 150KOhm at 50F.

Thanks for reading this far! Any relevant advice much appreciated!

Jim

 

if you have no heat in the cabin, then either your water pump isn't pushing the coolant OR the thermostat is stuck.

 

Thanks MiniToBe. When I start the car after it has been sitting overnight and turn it off after a few seconds (10-15), the fan runs afterward. I can't imagine that the fans are being commanded correctly based on coolant temperature. If the Mini uses an electrically-operated coolant valve, it would stand to reason that it is also erroneously being opened per your suggestion.

Seems like if the water pump was not working then the engine would be a lot hotter than it is after a trip - or not? It is quite cool after a long trip.

I wish I knew where the wiring goes from the coolant sensor and what other circumstances command the radiator fans.

Jim

 

Don't focus on the outside temp of the engine as a measurement. Check the obvious in terms of the water pump pulley spinning, the coolant pipes are cold, warm or hot. Run live data to see what the ecu is reading. The temp sensor wires go to the ecu and the ecu triggers the fan. In cases where the ecu isn't properly reading the temps, it fail safes the system by turning the fan.
newtis.info has the wiring for the circuit.

 

You'll get a code when scanned, likely telling you the thermostat is stuck open. As above. No code for water pump but perhaps a temperature fault would show. The pulley which runs the water pump is also prone to fail if you have the electric one (not all cars have this in USA and some run constantly). So, as MTB says, check the pump is running. Check the belt and intermediate pulley is OK. Look into changing the thermostat housing and maybe the water pump if not done recently as they are prone to cracking and leaking, the newer pumps are metal bodied and not plastic. Your engine will not run correctly until the faults are sorted as the ECU will stay in open loop with a thermostat/temperature fault so loss of power, hesitant on acceleration, wobbly idle. I would not drive it as you may damage the engine/cook it if the pump has failed. If it is the thermostat you could drive it but with problems as above.

 

Thanks for the ideas MTB and Scudder44. I will have a look this afternoon at the water pump. The engine light is on but my cheap reader doesn't report the value. The housing was replaced last year after it cracked.

Jim

 

My temp housing lasted 18 months because I bought cheap, stat stuck open. Now fitted with genuine BMW part uprated with lower temp (couple of degrees I believe) to reduce engine op temp. It wasn't cheap!!! Just to let you know that time does not make for a working part.

 

If the coolant pipes do get hot and your fan still runs at low engine temperatures, I would suspect that either the temperature sensor is failing or there is a cable failure from it to the corresponding ECU.

In my Mini's case, the temperature sensor would intermittently work fine and every once in a while (between seconds and several minutes) pass on implausible readings for again, between a few seconds and several minutes. The ECU recognised such readings as invalid and turned the fan on to be on the safe side. The fan would even run immediately when switching the ignition on without cranking the cold engine. The thermostat worked fine all along.

In order to check whether the temperature sensor is working fine, you need both:
- complete data on exact resistance shown vs temperature measured and
- measurements over time, spanning all possible temperatures.
Instead, you can check the actual reading the ECU receives within the "hidden menu". If it shows three stars instead of the temperature value whenever and while the fan is running, it is either the temperature sensor (most likely), a loose cable connection (not impossible) or a malfunctioning ECU (very unlikely).

 

Thanks for the help!

So the intermediate pulley is moving. Did not get under the car(yet).

I started the car and of course the fan kicked right on. I pulled the fuse to the radiator fan to stop it and monitored the cabin heat with the fan on high. Basically there was little heat unless I revved the engine. At 3000 RPM air temperature was substantially elevated but as soon as I let up on the accelerator, the air temperature returned to lukewarm.

I don't know much about the secret menu and didn't know it had coolant temperature. I'll check that out tomorrow.

Thanks again,
Jim

 

Quick update - very productive day!

Before leaving for work I set up the secret menu to display coolant temperature. While I was working on it, the radiator fan came on and went off a few minutes later. I had not yet started the car(!) After I took off, the display showed 3 lowercase 't' characters in superscript plus the unit (degrees Celsius). Along my route, I hit some rough road and the display showed somewhat believable temperatures for a few seconds and then went back to the prior state.

At highway speed the display still did not change. Then I hit traffic and came down to about 20MPH. Thinking back to the rough road, I noticed some rumble strips (big gouges in the asphalt to wake you up if you drift off the road). If you think those strips make noise at 60 MPH, try it at 20. The whole car shook violently as I steered the left tires onto the rumble strip....and the display began to show temperature! Back on the road, the readout worked as expected for about 20 miles/25 minutes. Cabin heat functioned normally and at highway speed, the coolant temp fluctuated between 48 C and 53 C. Then, while riding on smooth road, the display went back to the triple-t configuration.

So - I think this means the wiring is bad between the (new) coolant sensor and the ECU. Thoughts?

Jim

 

Not necessarily as the "connection" was "lost" and "returned" while you were still standing still with the engine not running yet.

Where did you get the temperature sensor from? Was it new? Can you rule out that air was left within the cooling system when you changed it?

Here in Europe prices for sensors by reputable after market manufacturers start at below 10 Dollars. I would just change it once again to see how that goes.

 

Thanks George - the new sensor came new from NAPA - $16.00. When I changed the sensor, the coolant level was just about at the level of the sensor opening.

Are you thinking the road vibration caused the sensor to start working for a while?

Jim

 

There are no moving parts within the sensor itself. Maybe it was just coincidence?

Did you bleed the system after changing the sensor?

PS: I just realized that you drove for 20 Minutes and the displayed temperature remained quite low. Provided this was not due to extremely low outer temperature, it would also indicate an issue with the temp sensor (either broken or wrong type), as does the intermediate display of the "triple-t".

 

Another thought (which shouldn't actually make a difference as to the temperatures):
My base Cooper LCI was manufactured in November 2010 and the thermostat casing it came with from fractory was the first version which did not allow for the temperature sensor to be replaced by itself. The new variant was fitted in 2017 when I faced the same symptoms as you do now. Since your car is from 2009 and you were able to change the temperature sensor by itself, I would assume that the thermostat casing is not the one fitted by the factory.

 

Quick report:
..
A few days ago I put some cardboard in front of the radiator to partially block airflow. That gave me some heat for the ride into work.
Two days later, after a 10 minute drive, the sensor started reporting actual values to the ECU. It kept working all day through all kinds of driving and about 60 miles of travel. In traffic, the temperature went up to 82C. I removed the cardboard halfway through this. On the road at highway speed, it stayed around 62C in about 38F weather.

I also had someone sit in the driver's seat and watch the coolant sensor reading on the hidden menu while I did everything I could to perturb the wiring harness and sensor housing but the the reading did not flinch.

Not sure where this leaves me but I'll monitor it and my next move would be to change the sensor out.

Jim

 

Some of the symptoms certainly point to loose or corroded wiring, but that shouldn't affect the actual engine temperature.
I suspect you need to bleed the air thoroughly out of the system. When you changed the sensor, you said the coolant was level with the threads - it should come pouring out!
Make sure the A/C is off as this affects how the radiator fan responds, cabin heat on high & cabin fan on 2 or 3, coolant at the correct level in the expansion tank.
On most cars, there are 2 bleed nipples - I'm not sure about the '09 base model. The main one is a plastic cross-headed one in the top center of the top hose behind the radiator. Open it as far as you can but don't drop it or lose it.
Run the engine until coolant, not bubbles, pumps out. Keep an eye on the expansion tank level & don't let it drop.
There are other methods including a vacuum one. There are many other threads too.
MINI heaters are notoriously difficult to bleed, so be patient & keep trying.

 

Thanks Mike - good advice - especially on what should have happened when I pulled the coolant sensor.
'
Yesterday (and the day before that) the car behaved just fine. Lots of highway miles. Coolant temp was about 62 C at highway speed at about 48F outside temp.

I will look at the coolant level and try to bleed it. Still wondering why the hidden menu displayed the "ttt" during the issue. And am wondering if it will go back to malfunctioning once temperatures drop back into the teens.

Jim

 

Subscribed...I too have a cooling fan that will start up/run when I turn off the ignition. Here is a kicker...I don't have to even start the car for this to happen. I just cycle the ignition on and then off and the cooling fan turns on. I don't think my specifics will help you but here goes.

2009 JCW that I purchased at an auction with no key or history. I never put electrical energy to the car before completing the following work (I didn't have a key for the car), so I don't know if it worked this way with the other sensor in the thermostat/water outlet or if I induced the problem with the work I performed. The coolant was low so I added some and discovered that the thermostat housing was leaking so I just replaced it with an "el cheapo" unit from Amazon. I also replaced the water pipe and the water pump. I definitely have air in the system, I have not attempted to bleed it yet. The key arrived from Germany and I put in a new battery after completing the repair above and I noticed the fan problem at this time.

I will report back with my findings but I plan on bleeding the system today although I don't think this is my problem because I don't even have to start the car. I will also see if I can swap the sensor in the thermostat/water outlet which sounds more like it could be the problem.

Good luck and let us know what you find.

 

@Chevycruizer:
Have you checked what the hidden menu displays as coolant temperature?

 

Chevy
I think you need to get the car running & driving 'normally' & see what you've bought before you start throwing parts at it. I wouldn't worry about the fan for now.
The fan may be running because it 'thinks' it's hot, maybe because of an air bubble. Idling the car to heat it won't necessarily work - it takes about 5 miles or so of normal driving to get the engine warmed through.

Chevy & HCC
Coolant temperatures, once warmed up, should be somewhere near boiling point 212F or 100C - t'stats operate around 185-195F. Anything near this is generally fine.

 

I haven’t checked the hidden menu yet. I need to find directions for this. I had a BMW 540i and got into it hidden menu before so I kind of understand, but will need detailed instructions.

I also have a very good scanner that should be able to provide some information if it is available. I used it in another Mini and could get into all of the different systems.

Im not a shotgun parts purchased by any means. But I will Chinese TO swap parts like a mad man. I planned on seeing if I can plug the sensors in from my old thermostat housing and get the same results.

 

Chevy
This copied from another thread - it works OK on an '02 R53Mini Secret Codes

Display Actual Coolant Temp

1. With the key in the ignition, but in the off position, press and hold down the odometer reset button with one hand.

2. While holding the button down, switch the key in the ignition to position 1 (first click) with the other hand. The screen will have a number and the word “TEST”.

3. Scroll through the numbers by pressing the odometer reset button, through to 19 and wait a moment. (Note: the number order is: 1, 2, 10, 19)

4. The message will say 19 "L i-off", flash to "L i-on", and back to "L i-off" again. When "log i-off" appears, press the odometer reset button again.

5. You are now in the system.

6. Scroll through to 7.0 Actual coolant temp.

7. Start the engine and go for a drive and you will see the temp fluctuation as the thermostat opens and closes. Your thermostat should start to open at around 90ºC

Don't forget, if you're in traffic or at very low speed, you will have heat soak due to lack of sufficient airflow over the engine, on open roads at highway speed, normal airflow should be sufficient to cool the fluid in the radiator and again you will see the thermostat open and close as required to keep the engine at its optimum operating temp.

Now, just to add to the confusion, the ECM activates the high-speed radiator cooling fan at 112ºC which also activates the EHPS cooling fan (if fitted).

Service Interval

1. With the key in the ignition, but in the off position, press and hold down the odometer reset button with one hand.

2. While holding the button down, switch the key in the ignition to position 1 (first click) with the other hand. The screen will have a number and the word “TEST”.

3. Scroll through the numbers by pressing the odometer reset button, through to 19 and wait a moment. (Note: the number order is: 1, 2, 10, 19)

4. The message will say 19 "L i-off", flash to "L i-on", and back to "L i-off" again. When "log i-off" appears, press the odometer reset button again.

5. You are now in the system.

6. Scroll through to 3.0 Service interval counter.

Reset ECU

This procedure is intended for a basic 'reset' of the ECU. It is not for clearing error codes or turning off CEL (check engine lights).

1. With the key in the ignition, but in the off position, press and hold down the odometer reset button with one hand.

2. While holding the button down, switch the key in the ignition to position 1 (first click) with the other hand. The screen will have a number and the word “TEST”.

3. Scroll through the numbers by pressing the odometer reset button, through to 19 and wait a moment. (Note: the number order is: 1,2,10,19)

4. The message will say 19 "L i-off", flash to "L i-on", and back to "L i-off" again. When "log i-off" appears, press the odometer reset button again.

5. You are now in the system. Scroll through to 21. TEST and wait a moment. 21.0 RESET will come up. Press the button once.

6. Your gauges will now make some sounds and movements.

7. Once the lights come back on start your car. You have now reset your ECU and your MINI is now ready to relearn the new mods and your driving style.

Here is a list of all the tests on your MINI:

1.0 Chassis number

1.1 Kilometre count

1.2 Parts number

1.3 Coding-, Diagnostic- and Bus-index
1.4 Production Date (Calendar week/year)
1.5 Hard and Software status
1.6 Injector status, Cylinder count, Engine factor.
2.0 Comb system Test

3.0 Service interval counter

4.0 Actual fuel consumption in l/100km. eg.0154 = 15,4 liters/100kms
4.1 Consumption in liters/100kms.
5.0 Distance consumption in l/100kms.
5.1 Actual rest distance with available fuel in Kms.
6.0 Actual amount of fuel in the tank. eg. 123321 =12,3liters left 32,1 liters right
6.1 Total amount of fuel in the tank

6.2 Show value of Fuel gauge:

1= both senders OK

2= sender failure

3=ti signal implausible (no reading)

7.0 Actual coolant temp

7.1 Actual outside temp

7.2 Actual engine revs

7.3 Actual speed

8.0 Hexadecimal readings of menu 7.0 to 7.3

9.0 Actual onboard voltage (Battery)

10.0 Land codes

11.0 Unit codes

12.0 No function

13.0 Gong test

14.0 - 14.4 Onboard diagnostic codes. e.g. 000000 = no failures

15.0 - 18.0 No function

19.0 On/Off for Test menu

20.0 Correction factor for Fuel consumption Formula for correction:

Shown consumption x 1000 / user-defined consumption

Push the trip reset button to begin the correction. Numbers count up from 0-9, when the correct number shows push the trip reset button.

20.1 Sets 10ths for consumption factor

20.2 Sets 100ths and 1000ths. For consumption factor

20.3 Saves the new consumption factor and shows the new value

21.0 Software reset. (Same as disconnecting the battery)

 

This is not quite what it is like on an R56. Here is a youtube video which shows the steps:

Notes:
- the "IP Test" is not required, one can scroll past menu position 2.x (and directly to 19)
- make sure that the driver's door is closed when starting the process.

 

Thanks for that, George.
I think it's a bit different from the 'Chrono' package, too.
Perhaps the moderators could make a 'sticky' for these.

 

So have you pulled the codes yet? Don't know why you're making this potentially more difficult when the car might be dying to tell you what's wrong. also then you don't have to deal with that hidden menu.
1. your running cool problem might be the fan running constantly or tstat. With the fan blocked or disconnected the cabin heat should come on and the temp should come up with the car at say 2k rpm. Might take a while if the tstat is stuck open.
2. Air in the system or bad water pump would make the system run hot.
3. Again with the codes. Id scan and clear, then disconnect the sensor and see if you get the same behavior.
4. 62' isn't warm enough to make a cup of tea.
5. Haven't looked into the mini system much, but assume that the ECU can close the tstat to get the temps up. If it was getting accurate temps from the sensors and if the tstat was functional, your cabin heat should work.