Car is an '08 MCS with 101k with auto climate control.

Over the past couple of weeks, I've noticed that it takes the climate system awhile to reach temperature.
This morning while driving to work, I got a yellow temp warning light and about a minute later, it came back, showing red.
I pulled over and waited about 10 minutes, then I opened the bonnet and there was really no indication of an overheat condition. I drove back home, taking it easy, and no light re-appeared.
After sitting a few hours, I checked the coolant level and it was at the low level. I added a little 50/50 mix to bring it up to MAX level. I started the car and pulled it out of the garage. I let it run about 20 minutes, then moved it and saw no evidence of any leaks. At the same time, I cranked the heat to max and now the temp always stays cold - no heat at all.

I'm thinking thermostat, but the temp light has me concerned - could it be something else, like water pump?

Thanks.

 

Just thought that I would add that no warning lights are currently lit.
There are no Check Control Codes (CC-ID) and INPA reveals no codes either. I was kind of hoping for something there that may give me a clue as to what is going on.

I need to drive my car but now am afraid to.

Thanks.

 

Maybe do some checking on google for these issues- NAM has a lot of solutions but the search function isn't very good. I replaced my thermostat when I discovered a leak from the thermostat seal, but I never got temp warnings. It's tricky to see coolant leaks because they tend to evaporate, but if you look around where the thermostat housing is you may see crusty deposits from leaks. There's a DIY or two on here for changing out the thermostat on S and Justa models.
If you can, check your hoses, too.

 

No heat is one of the symptoms of an air pocket in the coolant. Have you tried bleeding it? I'm not sure what the procedure is on a MINI, but I think I remember seeing it described around on this BBS somewhere.

You can use Google and add "site:northamericanmotoring.com" to the end of the search string and it will just search here. That often works better than the "native" search in a BBS.

 

I recall the S's have two bleeder valves (on separate hoses) while the justas have only one.
https://www.northamericanmotoring.co...der-screw.html

 

Thanks for the bleeder tip, I'll do that since its a freebie.

Beyond that, does the problem sound more like a thermostat or a water pump?
I've been reading on how both of these are troublesome with our cars. I just want to make sure that when I dig in, I do the right part.

Thanks.

 

I highly recommend reading up on your issue. I've solved many problems by doing searches on NAM. Often, you'll find plenty of people discussing and solving the same issues you are having.
This is something I found on MINI2 forum:

"In the case of the R53 MINI Cooper S, the water pump is driven off the end of the supercharger. This setup is a bit different than most cars (and R50 One/Cooper) where the water pump is driven off the engine belts. When a water pump begins to fail, you’ll notice that the car tends to overheat at low engine speed, such as sitting at a stoplight. When you accelerate, the engine temperature will drop. Now, this is not always indicative of a water pump, but a good starting point. You may also want to try squeezing the top radiator hose with the engine warmed up and running. You should feel pressure build up on the back of the hose and surge once it is released. If you feel no pressure, it’s a fair bet that the water pump is failing."
Pelican Technical Article: MINI Cooper - R53 Water Pump Replacement

It could be you're leaking from a cap or hose. or as mentioned above, a thermostat housing. If you are overheating due to an air bubble from not bleeding a hose, you may still have the primary problem of a leak that necessitated the top-off. Do a little investigation as see what you can learn about the problem.

 

I replaced the thermostat on my R50 using the DIY guide on NAM. It was pretty easy although it's a different procedure for your car. I didn't experience any of your issues except coolant loss. Since I knew the thermostat housings on my models year were prone to cracking I replaced the housing, thermostat and the coolant, bled the lines and all is fine now.

 

Thanks for all the ideas, Stanislaus.

I did do some preliminary searches but was unable to figure out if it leans towards the thermostat or water pump.

I need to dig a bit deeper into the NAM search engine and Google, like has been suggested.

I work in IT, and I always say that I'm not the first one to have a specific issue and if I am, then I'm in big trouble.

 

I figured it out: the thermostat housing is leaking.
I noticed that it was low on coolant again, so I filled it, bled it, and took it for a ride.
During the ride, heat was working fine and when I got home, it was leaking coolant at a decent rate.

So, now it's time to follow the DIY I found here.