I'm new to the forum, and looking for help! i',m original owner on a 2014 mini Paceman S coupe, and the heat just started acting up in the last week. it blows hot and cold intermitantly and not the season for that! As I've been driving I've been looking for a pattern to diagnose. Here's what seems to be happening: steady state cruising seems fine -- I took a 90 minute drive from Jersey to PA yesterday and the heat performed normally. but around town driving seems to be a different story. it seems to take longer to heat up from a cold start, and while driving, it will suddenly start blowing cold stopped at a light, or stop-and-go with accelerating and low speed cruising etc. I change the venting from floor to dash to defrost and that does not seem to change the temp. my guess is a thermostat thats stuck open? I'm tempted to try and replace myself -- been working on cars for many many years and skill set is pretty high. have done water pumps, alternators cam solenoids etc. of course I roll the dice if it is something else. but my dealer already said it would be like $400 plus part and I'm sure the part is near $200 for them! I can get it on Ebay etc for about $90. So I'm tempted to try and do it even if it might be something else. also would this show up as an error code in the diagnostics? I checked and it was clear. thanks in advance john

 

Usually means either low on coolant or air in the system. Pretty easy to check..

 

boy do I feel dumb! I checked the reservoir and it was empty which I'll take as a good sign given your comments! topped it off and it took a good quart of coolant. ran it for a few to circulate and will check it again after a drive. but my question is what do I need to do to get the air out of the system now assuming that's the cause? is that difficult? I had a fairly long chat with the technician when i made an appt at the dealer, and he cautioned me against taking on the repair myself -- he also said it was likely the thermostat and did not mention low level or air in the system -- but he also suggested the bleeding was critical after the thermostat replacement and best left to them. is this hard? thanks again.

 

there is a bleeding screw on the housing right next to the temp sensor.

I was going nuts on my 08 MCS yesterday. I decided to remove the screw and let it just bleed out while i put coolant in the reservoir. once it was a steady stream, I closed it and the cabin was hot

 

Ya, you've got a leak. Usually either the thermostat housing or the water pump. The last leak I had was the water pump.

 

I agree. You must have a leak to have lost that much coolant. but if you want to try bleeding the system first, there is a bleed screw on top of the thermostat. As MiniToBe said, you can leave it open while you add coolant.
Many people have mentioned that it's a little hard to find the screw. The thermostat is right under your cold air intake hose on the driver side of the engine. It's black, so it's a little hard to see without a flashlight, but once you find it the first time, you won't forget where it's at. You shouldn't have to remove anything to get to it, but you will need a somewhat long Phillips-head screwdriver.
It's easy to see if you have a water pump leak(or water pipe, which connects the pump & the thermostat). Just jack up your car on the passenger side, crawl under, and look up at the bottom of your engine. Coolant leaks manifest themselves with a whitish residue. If you see any on the bottom of the passenger side of your engine, or on your axle. wheels, etc., then voila', you have a water pump leak. You can change it yourself - follow the walk-through on Pelican Parts. My advice is to change the water pipe at the same time. (You'll want to remove your intake manifold for this, IMHO, to make it easier). Nothing will be more frustrating than changing your water pump, putting everything back together, only to discover that your leak is at the end of your water pipe where it meets the pump. you can do the whole job for less than $200, and have an improved metal, as opposed to plastic, pump in the bargain.
Good luck!

 

thx gentlemen will check it all out -- appreciate the advice.

 

Good advice above. Keep a close eye on the coolant level and look for signs of a leak. If you don't see anything under the car, look at the top of the transmission. Also check your oil and exhaust to make sure it isn't a blown head gasket.

 

I found the instruction on Pelican part is very good for water pump replacement, link below. Like other members had mentioned that it is wise to replace the water pipe between the water pump housing and the thermostat. I also applied dielectric grease on the o-ring of the new water pipe to help slide it in the water pump housing. When your coolant has been drained, you may want to take out your heater core and soak it in CLR. Why? It will be less coolant spilling on you carpet, and make sure that your reason for not having heat is due to a clogged heater core. Also, do not make an amateur mistake like I did after the water pump and tstat replacement. Make sure you tighten the ground cable on the engine bracket otherwise your car will not start. The nut on my car got loosen a week after, thus my car thought that it isn't ground and wouldn't start.
https://www.pelicanparts.com/techarticles/MINI_R56/78-WATER-Water_Pump_Replacement/78-WATER-Water_Pump_Replacement.htm

 

Classic case of a leak or air in the system, if nothing has been touched before you have a leak, either by the thermostat, water pump, or water pipe. You will need part # 11538674895 for the 2014 Paceman S , you will not need the adapter in the link. But its a good guide.

https://www.northamericanmotoring.co...placement.html

Here are the other locations to check.

https://www.northamericanmotoring.co...8-no-heat.html