Hi all,

I've been a fan of Mini's since 2008 when I bought a brand new one. Later selling it, then buying a 2013 model in 2020.

Recently, I purchased a 2008 Mini Cooper Clubman S that had the infamous broken valve issue, so I picked it up for $1000, tore it apart, and put it back together. At first, I got code after code, fan staying on til battery drains, and then, magically, codes stayed cleared yesterday on a test drive...

But... I have a remaining issue.. The Radiator fan stays on when turning car off until the battery dies. First thought.. Stuck relay.. That is NOT the issue.. Sadly. that would have been super easy :P

Here's what I did so far to diagnose the issue and try to resolve:

1. Verified relay - Good
2. Verified temp sensor (has whole new thermostat unit replaced). I put the old one back in, same exact problem. Even disconnected wire, which should cause computer to see low temp to keep fan off. No change
3. Verified bleeding of system, full reservoir, and system pressurizes when hot.
4. Cleared codes many times, even with enhanced Mini codes my scanner does recognize and clear. (NOTE: As soon as I clear codes, the fan would stop, then after a few seconds, activate the relay and run it again for no apparent reason)

During all this trouble shooting, I have found that the relay is being turned on after the motor is started, even if the running time is less than 2 seconds. (When engine sits overnight, I can put relay back in and no fan running).
I have tried the pushing the start button to turn fan off, and it goes off. Remove key, step out of car, and relay clicks back on and fan runs. Seems there is a very very long time before the computer turns the fan off.

On the ECU, if I disconnect the ECU, it does turn the fan off, so I know it's getting signal from the ECU. But, my concern at this time is, is the ECU a potential issue? Is it sending false signals to turn the fan on?
I've also noticed that there isn't much change in the fan operation whether the A/C is on or not. In fact, with the low fam relay out, the high fan never even starts, which I believe should start once A/C is running (Pump does engage).

Every single issue that people have suggested as a common reason for the fan to stay running, is not panning out. But, there is no mention of a bad ECU causing this. Has anyone experienced a bad ECU causing this?

Other than the fan, at this time, the car is running great and has stopped throwing random codes, the main one being a temp sensor code, which is not coming up now and hoped that would be that grand moment when the fan began operating properly again, to no avail.

I have tried to give as much info as possible, so feel free to ask questions. Please note.. I have been a mechanic in the past, so I understand a LOT of lingo regarding this stuff, so any suggestions are open, even if they sound advanced, lol. This particular issue if just baffling me....

Thanks,
Tim

 

So, an update. Took it out today and at startup, I had codes come up for fan 2ee8, and for the temp sensor. I know it's not the temp sensor because it works fine. I think the fan code was due to unplugging the relay, but not certain.

Is it oddly possible that a fan that seem to have a good working 1st stage and 2nd stage fan speed have something internal on the fan that is telling the ECU something? Which is causing the fan to come on, even when I do the quick button push to shut it off? Once I get out of car, the relay clicks back on and fan runs.

I also noticed that when I got back in the car 25 minutes later, plugging the relay back in before starting it, it didn't start the fan until after starting the motor. It's almost as if there's a time that is keeping it on for way too long (Where it kills the battery).

This is confusing and frustrating. Other than these codes and the fan running, the car runs great with the new valves and other new parts.

New Parts consist of:
1. full set of new valves (all lapped and seating well, guides were perfect)
2. new thermostat/housing
3. New timing chain set (full set)
4. New water pump to hose pipe that runs under the intake manifold. Old one had broken end inside of water pump.
5. other misc small parts that needed replacement, generally not related to engine running, just work out.

Water pump is also working fine.

 

Your problem is probably that you have the wires reversed between the temperature sensor and the pcv heater valve, which is located in the hose that goes from the turbo to the air filter box. Check those wires and see what happens, and don´t forget to clear codes after you switch the wires.

 

Thanks for the suggestion. Here's the outcome:

Swapped the connections and cleared codes, started motor. After a few seconds, got a orange temp light on dash, high speed fan kicked on, then red temp light came on.

So, I'm guessing I originally had them connected properly as things only got worse.

Shutting off engine, fans kept going, did the ignition switch on off to shut fan off. same timeline, fan relay clicked and fan started up again. Engine was not that warm at the time, so it should not have come back on.

Any other thoughts? I'm open to anything at this point lol.

Thanks again sub3622 for the suggestion...

 

I stand corrected! You were right. I was not giving up and decided to go back out and see what else I could find. I found a picture online where someone held the connector in hand and verified the colors. You directions were correct.

But, through trouble shooting, I had replaced the new Temp switch with the old one. So I decided to remove the old one and put the new one back in. Everything is 100% perfect. No codes, no temp lights, no fan issues!!!

Thank you for putting me into the direction. I had thought that the connectors were "keyed" and would not allow them to be mixed and most have color coding. Apparently, Mini chose to have two connecters similar and same length on the wire loom. Easy mistake to make..

Again, Thank You big time! You helped solve my issues!!!

 

Great, glad i could help.