My '12 MCS has problems making heat. Maybe just started or maybe it's just that cold weather has me looking for more heat. Anyway, no heat for about the first 15 minutes of driving then it comes on fine. No leaks anywhere I can detect. Thermostat? fwiw I noticed this after car had an oil change. Thanks!

 

You sure you have enough coolant? Low coolant will impact the heater core.

 

Thanks, added some coolant and all good. Now to figure out where the leak is...

 

Check the top of the gearbox housing for puddles. That indicates thermostat housing or pipe joint leaks. Front of engine (left as you look from hood) indicates water pump. Both DIY jobs. If you are replacing the thermostat housing, get new clips/or screw type clamps as the old clamps will most likely not form a good seal. I was told to replace the rear water pipe between pump and thermostat but on investigation it was perfect so saved a lot of money there. Forgot, one other high chance leak is from the coolant reservoir, they crack.

 

Has the car ever overheated? Sometimes a warped head allow coolant to leak into the cylinder that is blown out through the exhaust.

 

" gearbox housing for puddles." This is the first place it will leak, followed by the older plastic water pump on the passenger side and then check under the expansion tank for a slow leak:

All places to check here:

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

 

Don't overlook the coolant pipe and O-rings. If the car runs hot, easy to do with low coolant in the summer, the pump end can melt enough to cause a pesky consistent leak. At least inspect it any time the pump or thermostat is removed. I know the clip is a pain but it is part of earning your MINI journeyman card.