Thanks for the update, Yea the overflow tank, water pipe, and metal water pump upgrade I did all at one on the R56 MCS.

 

I broke a couple of clips of of the harness cover. The part number is 12527548064 but nobody seems to carry this. Does anybody know if you can buy it? I can't even find it listed online.

 

I just used some long tie wraps to hold the two halves together. The clips break on all of them. it just guides and protects the wires in the "L".

 

Shows part not on file. Do you have another part number or a picture of the part with that part number on it ?

 

I just zip tied it also. Somebody just manufacture this part, I'm sure almost everybody breaks it.

 

Okay, replaced the thermostat, bled the system repeatedly and coolant seems to be leveled off. Now my temperature gauge seems to fluctuate while driving. Tops out at around 230 briefly then goes down to 220 or lower but seems to work it's way back up to 230 before lowering again. I don't remember the fluctuations before. I seem to remember it sticking around the 220 mark. Do you think I have air in the system or another problem. Doesn't appear to be any leaks now. On a side note it has been hot hear lately, around 100 degrees.

 

Mine has always been steady around 220 except when the thermostat was failing or stuck open. I'd bet that you have some air in the system....did you have the heater on full when you bled the system?

 

Yes. No air out of the vent screw either.

 

Okay after further testing here is my results. Ran the air condtioner full blast, temp drops to 180. Temp fluctuates between 230 and 220 but never seems to go above 230. I ran the heater and drove slowly up my driveway which is somewhat steep to see if I could break any air bubbles loose. Vented again and did get some air but not much. Will refill overflow tank and keep you posted.

Larry

 

Mine is at 225-229 sometimes. When you turn on the a/c and hit the start button it will drp the temp.

If you run the heater and hear the air bubbles go through the heater core when you start up the car , you have air. I bled mine 3 times. Hot then let the car cool, then warm up and bled , repeat.

 

Great post. I swapped out the thermostat housing. Took me some time but I did it. I seem to still have some leaking but I cannot determine where from. I found one of the clips on loose on the heater core hose. I guess my next step is to replace all of the hoses running into the thermostat. I am trying to find the correct hoses but it seems a but challenging. Anyone know a really great diagram I can look at? I have a 2007 R56. Thanks

 

http://www.realoem.com/bmw/enUS/part...56-Mini-Cooper

This is what I used when I replaced my thermostat housing.

 

Thanks. Where would I find the little hose that connects from the thermostat to the turbo line?

 

Here below in the link: 11537567849

https://www.northamericanmotoring.co...ant-leaks.html

 

Silly question. By doing this repair could it mess with the clutch cable in any way? Taking off in 1st seems to be weird. Wondering if I could have messed anything up?

 

Not really. Unless you dropped something or messed with the intake or a pipe below that and it bumps the shift cables or selector right on top of the transmission. Double check you work and make sure the shifter moves freely.

 

I thought my auto trans gear selector was binding after doing my thermo. I took off the air piping and nothing was visually touching but after everything is reinstalled there is so little room that anything stray could interfere. I zip tied things together, made sure the wire/hose guides were all installed with wires/hoses being guided and it fixed whatever was going on down there.

 

My wife's 2012 R56 S developed a leak and turns out it was this thermostat housing. After reading the whole thread and watching the linked vid as well as the below vid by Mini Mania, I had the confidence to go tackle this issue myself and save $500 over the cost of having a repair shop do it.



So I find the part locally for $140ish. I accepted that price since I wanted the mini back on the road for my wife ASAP.

But once I started pulling the part, I realize the part on my wife's car was not quite the part I got from O'Reilly's.

The significant difference is the temp sensor connector... In that there isn't one. Or at least, not an external one like all the one pictured here and in all the vids. Instead it is integral and not removable, and the wiring connectors were COMPLETELY different.

After I get the part completely off, I compare the two and do a little research. Turns out this part varied a bit throughout the years, and it looks like there are basically THREE different versions of this part:

• The first version, which has the temp sensor at the top coming straight up. (Mini Mania Link)
• The second version, which has an integral, non-removable temp sensor and a little extra tab on the big tube going around the rear of the engine that a wiring harness attaches to. (No link to this, but will post pics below for identification purposes). Additionally, the wire connector at the front of the unit is wider than any of the other versions.
• The third version, which also has the tab but returns to a removable temp sensor at the top, but that temp sensor is angled instead of straight up. (Mini Mania Link) Also, we see a third type of wiring connector.

The second version is not available at all, and is replaced by the third version.

Most discount parts places only stock the first version of the housing.

Looks like there is an adapter that will let you use either the first (LINK) or third (LINK) version of the housing, which in either case is $3 worth of connectors and wire that is sold for $50+ (by the time you factor in shipping, etc.). Some local places could special order similar adapters, but again, cost was similar and time was being measured in weeks.

By the time I figure out all these details, it's 7 minutes until the dealer parts dept closes. Regardless, I call them up and they have the part in stock, and they will only rape me by $250 for the OEM part and adapter. So now I am down to saving $400 dollars by doing it myself. Still worth it in my opinion, but I wish I would have known this BEFORE I started, instead of getting half-way into the job and having to wait until Monday for the dealer to open up.

I could order the parts from Mini Mania, and I would have gladly but shipping would eat into any savings and it will still take an unknown number of days until the parts arrive. I need the wife's car on the road ASAP. So I am stuck with the dealer as the only viable option left in my case.

Anyway, here are some pics for identification of the 2nd version thermostat housing, which is no longer available and is superseded by the 3rd version.

Overview shot. Notice how wide the wiring connector is at the very front, how the bleeder screw has no temp sensor next to it in the upper left hand corner, and the extra tab on the far right.


Close up of new tab on the far right:


No temp sensor on top next to the bleeder screw:


Anyway, hope this helps someone in the near future. If you have a 2012 R56 Cooper S made before 07/2012, look for a temp sensor next to the bleeder valve BEFORE you order parts. If the temp sensor is straight up, you are good to go with any of the cheap replacement parts. If you have no temp sensor, you will need a adapter. If you have an angled temp sensor, you may be good to go just make sure the replacement version you order also has an angled temp sensor, otherwise you will need an adapter.

Here (LINK) is Mini Mania's guide to thermostat housings which explains in great detail what I have summed up above.

EDIT TO ADD: For the 2012 model year, that clip into the plastic pipe is way worse than anyone says because there are extra items in the way that prevent you from getting anything other than the tiniest of hands in there. If it were only as bad as the one in the vid above, I would have been done by now. Instead, I spent a couple hours this evening trying to get it in, and finally gave up. Will give it another shot tomorrow evening.

 

OK, some more tales for the later model year cars.

With the upgraded N18 motor, the whole thermostat area is configured differently. I found the wiring harness easier to work around (I only unplugged maybe 5 connectors total).

However, when it comes to the clip that holds the two plastic tubes together, WOW is that tough. Primarily, it is a function of lack of maneuverable space. The N18 motor has an extra cylinder shaped thingy-ma-bob hanging off the side of the head that is not present on the earlier motor (based on the two videos that are in this thread), I am guessing this has something to do with the double VANOS, but I don't know for sure. Anyway, I could not get my sausage fingers in the remaining space to align the clip.

Extra cylinder thingy in the center (silver with a plug attached)... shot from the top of the motor, looking down between the motor and the firewall. You can see the clip in place to the left of the cylinder.



Another angle, shooting from the firewall towards the back of the engine. Clip in focus, extra cylinder to the left. This really illustrates how little space there is.



I had to sit down and think about the potential solution, so I enjoyed a Popsicle or two while I contemplated. Then it hit me... the solution required using the two Popsicle sticks to "remotely" align the clip! Sandwich the clip between the two Popsicle sticks and squeeze the sticks tight together to maneuver the clip "feet" into the two slots of the thermostat housing.



It worked perfect, and after struggling for a couple hours earlier in the evening, the Popsicle sticks got me going in under 10 minutes. Once the clip is aligned with both "feet" of the clip in it's corresponding groove, I used my right thumb to push down on the clip and it easily slid into the slot.

One other adventure I had to deal with... my inch-pound torque wrench failed to click. This was only the second time I used it, and this was the result:



I was SO lucky that the bolt actually came out whole! This was the top thermostat bolt, and I was able to twist it right out intact.

I need to go buy a lotto ticket now.

 

If you do the replacement and find you still have leaks, showing as puddles on top of the tranny, more than likely it is the stupid hose clips, it they are not exactly back where they were originally they will never seal. I replaced all of them with jubilee style screw bands (worm drive hose clamp in Americanese) for a perfect seal.

 

Those work also, just make sure you dont crank them down too hard. They do hold better than those stock spring clips.

 

Just a heads up to anyone who got their replaced at a shop, I received a letter from MINI today saying they are extending the warranty for the thermostat housing (10yr limited warranty) and if you already had it repaired at a shop, you can submit your claim for reimbursement. I just submitted mine.

 

Just tackled this job earlier today and it all went to plan. Thanks for this guide, although I did also use the one on Pelican Parts too.

Few issues I faced were one of the circlips breaking so I replaced that with one of those screw type ones. Also, getting the plastic pipe to go in at the back of the engine was tough. Found that a bit of grease and titling it back towards the bulkhead helped.

Final issue was when refilling the coolant as it would sit in the reservoir and take ages to trickle through the system, even though I followed the Bentley instructions. Created a seal around the reservoir with my hand and blew in to it which helped push it through (and a ton of air probably) but I was keen to get on with my life.

Anyway, thanks for all the tips on here. Not a difficult job just fiddly and annoying

 

I just bought an '09 and the owner was going to deliver it to me. He overheated on the way down. He towed the car to his shop and they replaced the water pump,thermostat housing, radiator and heater core. I paid a little of the bill. Does anyone have more info on this "10 yr limited warranty"? and does it mater that you are not the original owner?

another note after all this work the car seems to have minimal heat.

 

In the letter I received, they gave me this website to visit and submit my claim.

http://www.mini-rp.com/production/is...ini_portal.nsf

I'm guessing, if you enter your VIN and your car shows up, then you can submit the claim.