Well, it's my turn to replace the thermostat housing now. My first engine repair since buying my Mini 5 years ago. Non turbo- but my local garage says that this is "common' on MINI. My local independent garage wants $350 for the whole shebang, and MINI wants $570, for what appears to be the same work. I'm not a do-it-yourselfer , so it's time for a 'car payment'. Anything else to o while it's apart? I'll have them look at the hoses.
Just when I was feeling good about my car's solid red dot on Consumers Reports...

 

It's my turn, too. I thought it was the water pump, because the water is dripping down the passenger side. MINI Ontario says it's the thermostat housing. Looks like my EasyCare contract is going to see it's $250 deductible.

Good news is that when they ran the info from my key, they could see that the previous owner had the water pump replaced just recently, so that's still covered under a parts warrantee. If it had been the pump, it would have saved me the deductible. At least now I know both common failures have been replaced

 

Does this apply only to vehicles that have to pass emissions in California? Or can I go down to my local Texas dealer and cite this warranty to get the faulty thermostat replaced in my GF's mini?

 

Any one have an issue with the CEL not clearing? Just replaced the thermostat housing, double checked everything and it still won't clear? I thought I remembered someone saying that it took a few days for theirs (and I'm looking for that post now).

Anyways, thought I would post here to see if anyone else had an issue. Thanks!

 

I had to get mine reset. Autozone may or may not do it. Got mine done at O'Reilly for free.

 

Ok thanks! Autozone did not or would not reset it for me. Thanks for the reply!

 

I'm pretty sure that after 20 successful driving cycles without a CEL it clears itself.

 

Hello,

I'm new to the board and this is my first time posting. Been a lurker for a bit.. I was doing a coolant change when afterwards there was no leaking but when the driving was hot / I was losing coolant. And sure enough there was a leak and a hissing sound. I've attached some picture and


and need to help identify if this is a leak from a 'cracked' plastic from the thermostat? Thanks Much!

 

any sense in replacing the water pump at the same time as the thermostat?

 

The water pump is a recall item. Take it to the dealer. Free is always better!

 

just the auxillary pump, right? Even if you're right and I have the dealer do the main water pump, that still leaves the thermostat, which they'll certainly rape me on.

Of course, it looks like the thermostat replacement is considerably easier than the water pump.

 

My bad yes that was the aux. Not sure about water pump replacement but the thermostat is really not as hard is it would seem. I can do it in about 30 minutes now lol.

 

I recently read a post in NAM that said a SA said the Tstat was part of the emissions system therefor had an extended warranty. I can't find that post now but would like to know if this is true--is so it would save owners money and time. Thanks

 

I just finished replacing my thermostat and am treating myself to a beer as I write this. Thanks for all the helpful info posted in this and other threads here on NAM. Below I've provided some points that might be helpful to others, particularly other newbs who haven't worked extensively on their mini before.

- I read at least one person in this thread who recommended buying hose hose clamp pliers. I bought one off ebay for $15 and used them extensively. Others seem to have done this job with ordinary pliers, but having these allows one to lock the hose clamp in an open/loose conformation allowing you to use two hands to adjust the hose and/or move the clamp off the thermostat.
- Plan to have some way to help remember how to reinstall the hoses, sensor plugs and wires. I used my cell phone camera to take pictures and movies, but this could also be accomplished by labeling items with tape.
- I ended up buying a small extendable/flexible mirror. I found this useful, but certainly isn't necessary.

To get to the thermostat you'll need to remove intake air tubing. There is a intake tube that runs from the air box at the back of the engine to the front by the turbo. On my car, it was held in place by two screw style hose clamps. Once loosened, its easy to remove the hose from the turbo and air box. There is a smaller tube that connects to this that also contains a sensor. You can twist and pull the small hose from the larger one. This allows you to completely remove the large hose, and the smaller one can be folded out of the way. I left the sensor plug connected.

There is another air intake tube that runs from a duct by the headlight to the air box at the back of the engine. There are no screws or clamps holding this in. A pull will release the tube from the duct at the front, but it needs to be twisted about a 1/4 turn counter clock-wise (I think), to release from the air box. I got it off, but I recommend removing the air box completely, mainly for steps later in the process, but it would probably make it easier to remove the intake tube. The air box has three posts that are held snug with rubber grommets, and simply pull out. In one corner there is a T20 screw by the battery on the passenger side of the engine that holds the airbox secure. Remove the screw, and lift out the air box. I think there is also a plug for a sensor that needs to be disconnected.

With the intake air tubing removed you'll see a bunch of coolant hoses, wires and sensor connectors keeping you from the thermostat housing. Start removing the various plugs to sensors. There are two on the thermostat housing, one that goes into the engine block, one that goes to the small tube you removed earlier but it doesn't need to be disconnected, another two near the back; 1 goes to the airbox/MAF sensor and 2) no idea what it is, but it plugs in facing up and is next to where one of the rear coolant hoses attached to the T-stat housing. I had a hard time disconnecting all these plugs. Many are difficult to see or access the clip to release it from the sensor. This is why I bought the mirror. These plugs also are not the same in how they connect, but for the toughest (one by the engine block next to the housing, and another that connects to the housing) you lift a tab near the wire side to release the sensor. I found a pick tool helped with this.

There were two rubber hoses, that ran from the back of the engine to the front. These sat on top of the harness and needed to be removed to be able to move the wiring harness out of the way. I think may be vacuum lines, but I'm not sure. One went into the turbo and the other into the engine block. No hose clamps on these, just a solid pull and they come off.

The wiring harness has two posts that sit in the thermostat housing. With a firm pull I was able to get the wiring harness away from the housing and it allowed me to mostly push the wires out of the way. Although this cleared the wires out of the way enough to get at the cooling hoses and thermostat housing, the wires were still constantly in the way. Maybe there is more that can be done to get them out of the way, but it wasn't necessary for me.

With the hose clamp pliers, remove the hoses connected to the thermostat housing. Two large hoses that run from the front, two rear hoses run to the firewall (for heating the cabin), and one smaller hose connects to the turbo, which is difficult to remove. The small hose doesn't have to be removed at this point. Be prepared for additional coolant to drain every time you remove a hose.

Remove the three bolts holding the housing to the engine block. They are tucked in pretty good and nearly impossible to see. However, they are accessible with a socket. I had a wobble extension that made this easier, but probably not necessary. Once the bolts are out, you can release the pin/clamp (v-shape) that holds the housing and the water pipe together at the back of the engine. This is where having the air box removed really helped me. This allowed me better access and visibility for releasing the clip, removing the housing from the pipe and helping with the install.

Once the bolts are removed and clip released, start pulling and wiggling on the housing. I struggled to get the housing to pull out from the water pipe at the back. In the end I eventually got it, but I'm not sure exactly how. I believe I tried holding the pipe with one hand and pulling on the thermostat with the other. This wouldn't have been possible without removing the air box. Once done though, you can get the housing out. If the small hose to the turbo is still connected, remove it now.

Installation is essentially the reverse, but I have a few points to help. As others have said before, connect the small hose to the turbo first, then the water pipe at the back. I had much less trouble connecting the housing to the water pipe. At this point it would be good to begin threading in the bolts to attach the housing to the engine block. It might even be a good idea to tighten it down. I didn't do it this way, and instead first connected all the hoses before screwing in the housing, which didn't work well. First the holes are impossible to see, and easier to access without the hoses installed. Also, the hoses pulled the housing out of alignment with the threads in the engine block.

Once the housing and hoses are connected, put the wiring harness back, reconnect the sensor plugs and the two hoses that I'm calling vacuum lines. Reinstall the air box, air duct and air tube that runs to the turbo. Replace the coolant reservoir tank, and reconnect the hose that you disconnected to drain the coolant in the beginning.

Fill with 50/50 mix. Squeeze the hoses, which will start filling the system. I pretty much followed the advice for filling and bleeding posted here with nothing else to add, and it appeared to go smoothly for me.

If it would help, I can post pictures. This job took me from 11/11:30 am till about 6:30 pm when I finally had the car filled, bled and running. I did take a few breaks along the way, so for me 5 or 6 hours total working time.

 

Thanks so much bbig119. My justa has 67000 miles on it, and I am just waiting for the thermostat to fail.

 

Curious on the post for this being an emissions item and covered under waranttee. That's huge as this is a total piece of JUNK part, brought to you by our "not normal" friends at Mini. I use to think that the whole Not Normal thing was cool. Now I think it may mean something else.

I had my original replaced under warrantee and it hasn't even lasted 2.5 years. Brutal.

 

Began having coolant issues over the past few weeks, and after filling it up, it just pooled on the floor by the front left tire. I took the duct, tube, airbox etc out and found the coolant pooled over the transmission. The post by bbig119 was really helpful. I found the whole process to be a huge pain in the ***, and it took me about 6 hours. It took me a while to figure out each step: the airbox at the back and the three tubes that run from the front to the engine block/airbox (newb here), hoses, the housing bolts and the V clip at the back. Even with the detailed description, it was just tough to understand each step before doing it but after doing each step, the description made sense. Not a fun process overall.

Regarding the wiring harness, I initially thought the black pipe like thing that contains the wires (photo in first post) has to come off, and ended up breaking several of the clips on it. This was unnecessary. The whole thing actually lifts off but does not come off and I just had to work around it while pulling the hoses off. bbig119 mentioned this in his post, but I didn't get it until i did it. Same with the 'vacuum' lines. Putting the new housing and reconnecting everything was much easier.

The wiring harnesses were all color coded and were relatively straightforward to reattach once I realized this. I agree that hose clamp pliers are essential for this. Also, I couldn't get to the front lower bolt on the housing with a 10mm socket that fit a 3/8" extension bit as there is no room. I had to get a thinner extension bit (1/4") to be able to get to this bolt.

In the end, I'm happy that I was able to do this myself without having to pay the dealership. A big thanks to bbig119.

I did check with the local dealer about the emissions control warranty covering this. This appears to be vehicle or model year specific as it didn't show up under my car's VIN when he checked (2007 MCS). Read on another thread here that mini modified the housing and made it a component of the emissions control from 2008 model onward. It is not part of the emissions system in the 2007 model and is not covered under warranty.

 

I have discovered a coolant leak in my r56 with roughly 63k miles. It has been requiring frequent top offs, and now I actually see coolant dripping from the bottom of the engine where it meets the transmission. Some poking around with a flashlight shows a wet puddle down on top of the transmission under the air intake tube and the wiring harness.

Would you guys say time to buy a new thermostat + housing?


EDIT: I did purchase a $1600 2 year 3rd party extended warranty when I got my car. I thought I would be able to cash in on it already, but they cover the water pump, the thermostat, and the gasket; but the housing itself is not covered. Oh well. I need at least one repair costing $1600 to happen in the next two years so that gamble will pay off.

 

Yeah, sounds like it might be. The thermostat is right above the trans location you are describing, and right below the fresh air tube going into the air box. I'd order a new thermostat just to be on the safe side. Mine never leaked, but threw a CEL for ~3K miles off and on for "5079 - Thermostat stuck open." Just replaced it this weekend. Sounds like yours might be split, which seems a pretty common failure for this part.

 

So mine since threw a CEL. Took it to dealer and they told me the previous owner brought it in with a CEL. They told her needed a new thermostat, and she declined. Apparently she traded in the car soon after clearing the code.

 

That sounds like a leaking thermostat to me.

The thermostat and housing comes as a unit....they cannot be separated. It's one piece/one part...not like a traditional setup on older cars. You might suggest this to your warranty company or ask whoever does the work for you to go to bat for you with that info to get it covered.

Good luck.

 

I'd bring the fact that it's all one piece to their attention. They probably don't know it's one unit.

 

Good call you guys! When I gave them the part number and explained that was the only way to get a new thermostat, they said it would be covered. Appointment is Friday morning.

 

so i did mine today but i think i crossed something bc now i have a rough idle and also my fan is running after i turn the car off for a few minutes...can someone please tell me the color code for the wires to the connectors.....if i know that i think i can guide through the rest and figure it out....thanks ...pictures would help alot thanks

 

Im not sure how I did it because the wires seem to be following their "natural paths" but I may have crossed sensors. Im getting a rough idle (I'm about head out to run the codes now)

Does anyone have an idea as to which sensor goes to which plug? I would sure appreciate it.

Thanks!

EDIT:
The rough idle seems to have dissipated but I am in running in limp mode (i think). The check engine light came on and I have a pending OBD code of p0001 which has something to do with a fuel volume regulator control circuit? I've cleared the check engine light but the pending code of p0001 came back which probably means something is not right. :(