Hi All,
My 2006 JCW has had a slow coolant leak for a little while now. I would notice a little puddle under her in the mornings, so I have been topping the coolant reservoir every week or so. Guessed that it was the thermostat housing, so I ordered and installed the housing and new thermostat. Bled the system and the leak got worse. Now when I put coolant into the reservoir, it immediately pours straight out onto the ground from the front of the engine. It's a steady slow flow out. Not a flood like a hose is disconnected, but more like there's a hole somewhere and it's trickling out.

I tore into her today by removing the front bumper and crash bar, the underliner, and fender liners. When I add coolant (water at this point), it seems to be coming out somewhere behind the super charger. Does this automatically point to the water pump? It seems the leak is about center of the engine, on the front.

I don't recall hearing any of the typical water pump failure noises, but I don't know what else it could be. Are there any coolant hoses that run between the supercharger and block? Should I look at anything else? I would really like to see the water leaking from the water pump prior to pulling the supercharger/water pump and purchasing another.

/Kevin

 

A leak like that at the front of the engine and back of the supercharger sounds like a water pump, or at least the oring for it. But we always do both at the same time. If you need a water pump only get the factory one, we've been burned by the aftermarket ones so we won't even sell them as it's too big of a job to do twice.
https://www.waymotorworks.com/r53-water-pump.html

There is also this small hose that connects the water pump to the pipe that runs under the thermostat.
https://www.waymotorworks.com/water-...e-r52-r53.html

 

The water pump is three pieces. The pump itself has an inner and outer section held together with torx screws. There is a rubber o-ring in this area. The third part of the pump is a portion that attaches to the engine block. This also has a round rubber o-ring were it slips inside the main pump body. If you are seeing water from "behind" the SC, it could be this o-ring or where the third part mates up to the engine block. Use a flash light or bright work like to see these block bolts. You do not have to remove the main pump to gain access.

There are also several hoses in this area as the t-stat housing is about 6 to 8" from where the pump attaches to the block.

 

Thanks for the replies. What will I have to remove in order to see the block that's covered up by the SC, if not removing the SC? How many more hours are involved once I have the radiator removed (where I am now)?

I would like to check the SC oil while I'm in there.

 

I just did this overhaul. It was the weep hole on the WP. I'd also replace the SC oil at the very least along with the intake gasket. I had very little oil in both the front and rear. Modmini has a good video on youtube. If you already have the radiator out your almost there pretty easy.

 

Below are some links for other threads here. You can remove the supercharger or not. The PIA is the BPV as with it in place you access to the water pump and all the hoses is limited. For the first time, and even with the radiator out, I would figure at least another 3 hours but you should have all your parts in hand first. The first thread below has a good list of what you need and pictures. The second has a video on how to do without taking out the sc. I used this method but in the thread I added some other notes.

https://www.northamericanmotoring.co...-mcs-only.html

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

I also put in a new t-stat and housing. It was easier to get the clamp rings back on the water pump hoses with the t-stat housing out.

 

We say it should take the average DIY'er about 2 hours to do the replacement. I suggest you take a look at our DIY here for help: http://www.pelicanparts.com/techarti...eplacement.htm. Make sure to use MINI coolant 50/50 with distilled water.

Also, if you do decide to service the SC while doing this job, take a peek at this article as well: http://www.pelicanparts.com/techarti...nd_Service.htm. If you need any help with recommended parts lists or have any questions please don't hesitate to shoot me a PM.