First of all I want to apologize for creating so many threads lately, but it seems I'm having a lot of problems lately.

Timing chain components, valve cover (PCV), FRM computer and now a plastic housing that seems like it's cracked and has many sensors going to it. It's located underneath the HPFP/vacuum pump, I could only visually see it after removing the air intake pipe that leads from the airbox to the turbo.

Help appreciated!

Regards Systemlord.

 

Cracked thermostat housing? Any coolant leaking out of it?

 

It's cracked around the base or mounting area. I first notice coolant leakage when I came home from the beach, I pulled out of my drive way and they was a puddle of coolant. I checked my reservoir and I only lost about a 6-10 fluid ounces, I then notice underneath the car that the coolant was dripping down the back of my tranny. I then removed the stock induction hose and I see fluid leaking out a fine crack, is this a known (common) issue? Is this an easy job for the do it yourself mechanic?

This would never have happened had it been made of aluminum!

 

Systemlord, Boosted Mini does a good 'how-to' on NAM...

It seems the plastic housing stands proud and is tightened onto the gasket and deforms eventually. I'd also be minded to keep the original sensor if they provide one new since there have been reports of thermostat/sensor temp. mismatch. I think there's an aluminium version in the US. (I made a mental note of replacing with one if it became a d-i-y project for me. Under warranty they still replace with OEM plastic don't they?) Bleeding properly seems important, too.

Some NAM advice; I've included a pic of the housing, too.

I would say the biggest part of the job was all the reading of other peoples threads and how-to's. I used the search button, typed in "thermostat", picked a thread, read it and moved onto the next one.Thanks NAM community. The removal and installation was pretty straight forward.I waited to remove the housing until I had the new one in hand so I could see where the three bolts are located and so i could see exactly what I was removing. I also opened the bleed screw to see how much I could safely turn it when I bled the coolant system. I re-installed everything and made sure everything was back together where it should be (labeling made this very easy.) I then used the search button for bleeding the coolant.
What I did was:
1-open bleed screw on top of housing
2-remove expansion tank cap and fill to max line
3-turn car on, but not start it, nothing really was happening
4-started car with bleed screw open and expansion tank cap off
5-jammed my big left hand between expansion tank and air inlet and squeezed coolant hose to help air escape through bleed screw while watching coolant level in expansion tank and filled as necessary WATCH OUT FOT THE FAN!! Can be done more safely from underneath, I think?
6-closed bleed screw and put cap on expansion tank
7-turned Benni off and let cool for a bit, also checked for leaks (there weren't any!)
8-repeat steps #1-7, skipping step 3, until coolant level stopped dropping in expansion tank
I hope this provides you guys more insight on how to bleed the coolant. My biggest obstacle was the bottom front coolant line that goes from the housing to the turbo hard line. The hose clamp on there was the most stubborn of all the hose clamps to remove and install. just be patient with it and it'll come off.

 

Wow thank you for all of invaluable information, this provides a clear picture on what needs to be done. Once I remove my AEM intake pipe I should have more room to work with, even though I'm under warranty the only mechanic you can trust is yourself. I can't be sure if the older sensor is used unless I do the job myself. I might as well replace the main pump to if it's located underneath the thermostat housing, is it?

Regards,
Systemlord

 

Systemlord, Boosted Mini also does a water pump post on NAM:-
R56 :: Drivetrain :: DIY Water Pump Replacement

It looks like the pump couldn't be further away from your thermostat, being low down on the (US) passenger side front of the engine. IMO doing both makes sense though, regarding coolant replacement/bleeding..

I have a feeling that the OEM pump is also black plastic but, again, I'm almost certain I saw in the UK that there's an aluminium version that I'd use in preference if I were d-i-ying. It must be available in the US...

Again, loadsa luck! Those two cheap plastic products must have been (and continue to be) a big 'earner' for MINI/BMW.

(I wonder if they're the new 'designed in cash cows' (IMO) like the BOOST hi-fi 'improvements' that could be more cheaply solved by the channel swap, which then was dropped in favour of replacement by more-upmarket-and-expensive-HK when it became common knowledge. Or am I being paranoid?)