So I decided to fix my 2012 cooper s myself. Had a coolant leak at the oil cooler so I remove it and found one of the holes is clogged with something. Is it a simple clean out or is there a bigger issue? This is my first post so hopefully there will be pics.

 

You can definitely clean it up......the housing separate........I'd also flush the entire
system.....

 

Looks like some kind of coolant leak stop goop. Ugh, that stuff should be outlawed. DEFINITELY clean out what you can and flush the rest of the system. Hopefully, it isn't clogging anywhere else...

 

@MrEnso ,

 

So the heat exchanger is clean and got as much out of the housing I could. How would I go about flushing the system when I have the front end off? Tried pouring distilled water into the reservoir but it comes out the top of the housing and it is the bottom that is clogged. Is there a way to maybe flush through the thermostat? Changed the water pump also and nothing in there.

 

Get a radiator cleaner and let it run through the entire system with the heat on.......... and then flush with clean water......Until you see the water is clear.......then add your antifreeze