I replaced my heater core this week and decided to post some "tips" or advice... and if anyone has any questions about the job feel free to PM or email me. Sorry so long.

First, my symptoms- mist coming out of vents, oily fluid on driver's side floor.

I got the core and install kit (insulating foam, o-rings and clamps) for around $130. I put the car up on jack stands, pulled off the black plastic band on to access the radiator.. pulled off lower tube and drained system. WARNING- coolant will go everywhere since there bit that block a straight stream. I could not locate the drain plug for the motor so there was 1/3 of the coolant still in the system.

In the cockpit: I removed the cover by removing the three screws (20 torx) and working the cover out. The one in the top front is a huge pain and you will have to work from touch/feel. removing the clamps (allen wrench) and screw is easy at this point. Knowing I still had coolant in the system... at least what had not drained onto my floor- I needed a way to collect the coolant. I did not have a pan so I grabbed a big funnel and jammed it into an old piece of garden hose (taped with duct tape) that ran to a pan outside the car.

There are two metal hoses pipe coming from firewall that connect into the core. they have some play and I could not disconnect them so I pulled the core out and then they come off easy... along with a lot of coolant...

reinstall- Put the foam around the core- PUT THE O-RINGS AROUND THE PIPES... they will pinch if you put them on the core- learn from my experience. Slide the core in.. as you get close to the pipe pull them toward the core (out from the center towards the gas pedal) and place them in the holes. As you slide in the core they will set.

CLAMPS!!! Save yourself some cursing. When I was trying to put the clamps on the pipes would not go into the core enough without me putting pressure on both core and pipe. After cursing, squeezing, cursing, etc I tried rotating the pipes slightly and they set in nice and tight! The clamps then go on easily. You can finish the rest, just screw in the screws to hold the core and then reinstall the cover... i skipped the top front screw b/c i could not get it to set in and was frustrated.

Filling and bleeding the coolant system- According to haynes I should have filled the coolant reservoir and open the bleed screw (on the hose that crosses the top front of the engine bay- Plastic with a big X in it) and let the coolant run until there are no bubbles coming out of the bleed screw.... Yeah right. I filled the reservoir, opened the screw and nothing happened. The tank level did not move and nothing came out of the screw. I started the car and let it run for a while. Once the thermostat opened bubbles came up in the reservoir and eventually the coolant flowed from the bleed screw. I watched the reservoir and filled as needed and let the car run for a while. WARNING as air moved through the system the level in the reservoir raises and falls quite a bit and even overflowed. I turned off the engine and let it cool- the reservoir emptied completely so I refilled. I ran the heat up cool down cycle a couple of times adding coolant as needed.

The whole project was pretty easy just time consuming… the MINI dealer charges 4 hours and the “book” recommends 8. I did it myself in 2 with the heat up cool down taking the most time.

I know I did not add pictures, sorry but I did not take any, but I hope this helps a little.

 

Where'd you get your replacement parts from? My dealers don't have it in stock and I can't find it online. I guess I'll have to ask the dealer to order it for me.

 

I had Eddie at 1FastMini order it for me. All the dealers were out of stock and had to order them anyway and I trust Eddie