Hi All!

I'm guessing this is going to be a real expensive fix. My wife pulled her 2011 S with 14,000 miles into the garage yesterday, and said that the radiator fan wouldn't stop running for a very long time. When it finally shut off, i looked at the coolant level, and it was just below min. I added 1/2 cup distilled water to bring the level just up to min.

We took it out for a short ride today, and the steady yellow check engine icon on the speedo is lit yellow. Brought the car home, shut it down, and the fan runs on.

I waited a few hours to check the coolant level, and it has dropped a little. Started the car, and I have the same yellow check engine icon on the speedo. I shut it down after 30 seconds, and the radiator fan runs on.

Anyone want to guess before I take it some place to read the code tomorrow?

 

Thermostat (had the fix?) and / or thermostat housing would be top of my list...in fact, I think I'd replace both while it's stripped down. IMO it's not really the mileage so much as a poorly-designed-gasket-and-plastic-part.
I'd be interested to find out what that eml code is, so pls keep us posted.
Hope it's an easy 'fix'...loadsa luck!

 

Original thermostat. I should add that I live in Texas, and the fan has never run nearly this long in the heat of summer (it's cool now). I never realized how much I would miss a temperature gauge on the dash.

 

Just a thought...why not get a wireless OBDII reader + Android / iphone app?
Really cheap + cost-effective! I use mine to check temp readings are ok after a coolant flush and to 'keep an eye' on temps during a long journey...

 

+1 get a OBDII diagnostic tool and pull the code. That will help us determine what may be the cause. Do you see any leaks under your MINI? Could be very slight as the thermostats tend to get hairline cracks.

 

P0128. No leaks under the car.

What I don't get is why the fan runs so much after the car is shut down. It never did this much before. And like I said, it's cool here now. The unusually long fan run-on is telling me that the car thinks the engine is hot. How does a stuck open thermostat or slightly low coolant level (due to a small leak somewhere) cause that?

 

According to Engine-Codes, possible causes are:

- Leaking or stuck open thermostat
- Low engine coolant level
- Insufficient warm up time
- Faulty engine coolant temperature sensor
- Engine coolant temperature sensor harness is open or shorted
- Engine coolant temperature sensor circuit poor electrical connection

Might be time for a new thermostat. We have them HERE if needed. Adapter lead here. Let me know if you have any questions.

 

Thanks! I can see that that a leaky thermostat is the only one that could drop the coolant level. But what is causing the radiator fan to continue so long? Is it just that the leak has caused the coolant level to go below 'min', or do y'all think I have a second P0128 issue?

 

You're welcome. I'd think it's because you're low on coolant. I'd replace the thermostat and see if it continues once you get everything in working order. Also, for reference check out this thread here. I linked to a good post. Let me know if you have questions.

 

That's what happens when the coolant is low enough , after you shut the car off the fan runs for a long time as the temp sensor is not reading the coolant itself because its low.

Did it on my car before i replace the thermostat housing .

 

I had this same issue last month. CEL, P0128, radiator fan running for 15 minutes after shutting off car. I replaced the thermostat, and everything has been normal ever since. Thermostat and housing and coolant temperature sensor are all one piece, and cost a little over $100. My guess is that the coolant temperature sensor had failed, making the car think it was hotter than it really was, so causing the thermostat to stay open all the time and the fan to run after the car was shut off. The JOY of an electronic thermostat.

 

Thanks everyone! Sooooooooo helpful. Have there been several 'revs' of this item? Which 'new' replacement thermostat housings have been lasting longer than others?

 

You're welcome. The one you're wanting is HERE and is the most current one from MINI. If you need anything else let me know.

 

This is the N18 version one, they also updated this part on the connector from the last one.

11537647751 KT



Follow the same install as the one linked for the N14.

 

OK. I just got home after snowboarding all winter, and I'm ready to tackle the mini problem.

If P0128 is thrown when the coolant temperature is too low, why does the fan stay on so long after shutting down? If the system thinks the engine isn't hot enough, the fan should shut down right away.

Any chance that the fan is running too long, and that is what is causing the code?

 

P0128 is 0x2F07 Coolant Thermostat (Cooalnt Temperature Below Thermostat Regulating Temperature) or 0x348A Program map thermostat: Sticking in open position. It could be the thermostat has an issue or a small leak. Typically they start as a hairline crack and pool on top of the transmission. I'd still recommend replacing the thermostat and adapter lead.

 

OK. But why would either of those make the fan run on? If I have a low temp and/or stuck open thermostat, shouldn't the fan shut off immediately?

On the other hand, if there was an issue with the fan control, and it was on when it should be off, that would cause a low temperature, and trigger the code.

I'm with y'all that the thermostat housing is most likely the problem. I just want to completely understand why that fan is on.

 

The fan can run when the coolant sensor is faulty, shorted, reads too high, or when coolant is thought to be low. However, it may also run if there is a fault with the thermostat. These are our observations. I don't know what MINI has programmed in the DME for temp protection, so we have to guess. You should repair whatever is causing the P0128, then worry about the fan, if it still acts irregularly.

 

Happened to me , extra long fan run

When the coolant level is low in the thermostat, the fan kicks on because the sensor is out of range and it think there is a overheat because the engine was on. No , the fan 99% does not cause the code, its a leaky thermostat housing or a leak somewhere else that cause the low coolant level, Get it changed or check out asap, you dont want to overheat the engine.

 

OK. I can see that. Fail safe mode would be to run the fan if the temperature sensor faults or if the coolant level is low. The fan now comes on as soon as I turn the key.

 

Yep, Its very low on coolant, mine started to come on with long runs and then short runs, then all the time, I knew it was leaking ( pooling on the transmission, my own quick MINI insider find I talked about in back 2013 on the MINI forums ) , that was right before i changed it. Been good ever since.