I understand that the coolant temp sensor is like the bain of everyone's existence. I have the tabs open and search history to prove it. But I'm trying to help my father with his MINI and i've lost a couple days of my life already trying to sort this out - otherwise may tow it to shop. Okay lets go:

Fan running constantly, we know the issue is thermostat, got the code, I'm a BMW guy, so i have a BMW/Mini Scanner. Check. Car is a 2012 Cooper S, order the part, shows up, its not the same one, its straight. My fathers is the "angled type" as i've come to learn. (turns out from a 2013 build date?) I finally found the right one to order, got it in, and after removing the old one, there is NO getting that retaining clip back in. I've taken out the coolant reservoir to give more space, but no matter the patience or effort i can't get it. I have two questions....

1. I know there's a wholeeee thing about thermostat replacment where they relocate temp sensor. I dont even understand the why of that... but is that something i just need to go ahead and do? But am i right that i still have to get this damn thing back in because even tho its rendered useless, it still has to be there becuase they didn't make a plug? And its likely to leak? Cool.

2. Can I remove the silver part of the top of the motor (pictured with red arrow) to free up a tiny bit more space to try to accomplish this task?

Any insight into this would be great becasue i'm at a loss and my dad needs his car, just been trying to avoid towing it to a shop, or worse, dealer.

Thanks very much.

Pic for clicks.

Red arrows indicating part i wonder if i can take off without any fluids pouring out. Car hasn't been run in about a week.

Here you can see angled sensor

 

The red arrows should be the vacuum pump. You can remove that. Little oil residue might leak but it's not going to pour out and lose a bunch of fluid. Can't really help with your other question as I have the N14

 

So here's the story as I know it:

-The temp sensor was originally in the thermostat: that version had issues where it would corrode and fail, and there was a recall or service campaign
-The retrofit fix was to retrofit a separate inline sensor in the upper coolant hose from the thermostat using a pigtail adapter to the existing wiring
-The revised thermostat design has a different temperature sensor, again located in the thermostat. I think this requires a different pigtail

On my 2012 the original temperature sensor failed so they installed the retrofit sensor. Then a few years later the thermostat failed: they replaced the thermostat with the new version with the revised, integrated sensor. So the car was using the temperature sensor in the thermostat and the retrofit sensor was still installed but not hooked up or used.

So basically it's not simple: there can be a lot of variants out there and you need to figure out what exactly you have to determine which sensor, thermostat, or pigtail adapter you need. Found this doc online, maybe it'll help?

 

If your changing out the thermostat.......remove the airbox and related connections for the airbox...
this will give you more room to remove the bolts and hoses connected to the housing....
Have you ordered a new crossover pipe...... there's two different thermostat housing one being
for the N14 motor and one for the N18......once you remove those pieces you'll have more room...
I've never removed the vacuum pump to change out the housing.....Let out the antifreeze will
stop it from running all over the place.......

 

The straight one is a thermostat housing for the N14-------the angled one is for N18.....

 

What retrofit sensor......did you have a metal elbow with a sensor connected by hose to the housing......
If you did that was an old unit which is no longer used......so you would need a different hose as well
​​​​​​​to eliminate that.....Please post a picture of this retrofit you talking about......

 

Yes, this one, bottom center of the photo. That's the one that Mini retrofitted as a fix for the original thermostat issues.

For most people it's definitely still used. If you subsequently get a new thermostat then it just gets unplugged and left in place, and the sensor in the new thermostat is used instead.

 

Thats definitely elbow is definitely outdated.......You need to get the thermostat housing for the N18 engine
also order a new coolant hose and eliminate that elbow all together because it's no longer used...also order
the new pigtail, because the pigtail connected to the elbow isn't used also...... the easiest way to do it for
you is to plug the harness back into the external elbow sensor......then proceed to remove everything connected
to the airbox so you can look at the housing and coolant hoses......look at the rear of the thermostat housing
remove the little clip that secures the crossover pipe to the housing use the needle nose pliers ...the proceed
to remove the coolant hoses on the rear of the housing.....then remove the hoses connected to the metal elbow
as one unit, because you will not be using none of that again......also remove the pigtail with it as you won't be using
that again also....you'll see a wider part of the pigtail disconnect that......it will now be removed with the elbow....
then get your socket and extension and remove the 3x bolts----- I believe 10mm definitely 6-point...once you get this
loose you can navigate the remaining hoses......also get the new pigtail that's one unit and not 2x separate plugs...
order another coolant hose it will be longer to connect to the housing.....

 

I've done this this same process it's definitely not used......if you check ECS tuning you will not see it listed
nowhere on the site-----if you check the mini cooper dealership you wont see it listed as well.....the reason for
the upgrade was to get a better temp reading by incorporating the sensor into the housing......That elbow
was introduced on the 2011 N18 engine.......

 

Why would you still leave it in place if it's not used when you can just change the coolant hose
and clean up the area as well .......the new thermostat was the fix associated with the issues
caused......

 

Yoshimura, you are wrong. That elbow was not introduced with the 2011, it was a retrofit in ~2013 to fix issues with the original N18 thermostat. My 2012 did not have that elbow from the factory; it was added by the dealer to fix a failed temperature sensor (corrosion) in the original thermostat.

If you subsequently install the upgraded thermostat part then, yes, that elbow sensor is no longer used and you can replace it with a solid hose. In this case I don't know which setup Kegsworth has, so I'm not sure exactly what advice to give. He needs to figure out what version thermostat he has and what's been done to his car first, because at this point there are a few variations out there. If he has the original thermostat then replacing it might be the right way to go, but I can't just say that from the info provided.

 

My 2011 R56S was equipped with that very same setup with the metal elbow.....That was immediately removed after temp issues

 

I don't doubt it, but it did not come that way from the factory. That was a retrofit part to fix issues with the original thermostat. It only came on cars from the factory built between 3/2013 to 7/2013, see picture below.

Kegworth, I found this doc online that may help you figure out what version you have and what you need to do: https://dot.report/bulletins/10145369

 

Thanks I'm off this topic.......only trying to help him fix his vehicle......