MINI Cooper water pump replacement

Well, after almost 96,000 miles it was time for a new water pump. After replacing the inferior original thermostat with an upgraded one in 2009, I once again started noticing coolant loss from the reservoir tank and hearing the familiar sloshing sound behind the air conditioning/heater controls. The sloshing sound was coming from the heater core indicating that the coolant level had dropped and air had been introduced into the system. I figured it was highly unlikely that the thermostat gasket had failed again. A quick peak under the car during an oil change revealed that quite a few blue coolant boogers had dried on the A/C compressor, which is directly below the water pump. Time for some wrenching.

Firstly let me start with a disclaimer. Replacing the water pump on your R50 MINI Cooper is not an easy job. This is not like changing your oil or even doing a brake job. You have to remove the front half of the car to even see the water pump. This means lots of careful removal of plastic parts, the metal bumper, keeping track of lots of bolts and screws as well as draining the radiator…and all of that before you ever remove the water pump. If you are a relatively experienced mechanic, this will be something that you can handle just fine. But if you’ve never attempted something of this magnitude, it may be best to seek help from an experienced mechanic buddy or just pay up at the dealership or your favorite shop.

The first step was to raise up the front end of the car and remove the front wheels. I am always sure to use jack stands to secure the car. Once the front wheels were off I removed the inner fender covers. This is an easy job but the little black plastic fasteners can be a pain. Here’s a tip, use a Phillips head to unscrew the center cap while simultaneously gently prying up the plastic cap with a tiny flat head. The center part should unscrew easily and allow you to remove the whole fastener. There are also a couple of real, metal screws holding the cover on near the shock mount and under the front bumper cover.

Next, I removed the lower bumper cover…not that part that has the grill and turn signals in it. There’s a smaller plastic cover that mounts below the engine and radiator and is attached to the bumper cover. Remove the two Phillips head screws and the three 10mm silver bolts to slip it out of the way. Mine had a crack starting to form so I slathered it in epoxy to stave off a full on break.

You’ll need to remove the serpentine belt too, might as well do that now. I use my nail puller (you know, one of these things) to created enough leverage to push up on the belt tensioner from below and slip the belt off the idler pulley with my free hand. It takes some practice but now I’m pretty good at it. Be sure to make note of how the belt loops around each pulley. It’s pretty obvious really as the ribbed parts of the belt need to be in contact with the grooved pulleys. The idler is the only one without a grooved pulley so the back side of the belt is looped around that.

Pulling the bumper cover off isn’t a big deal. There are a two bolts near the wheel well area that look like this:

You’ll need to have both fender wells off the car to get to those. Next remove the two Torx head bolts…you do have a Torx head socket kit, right? They are located along the upper edge of the cover.

And lastly disconnect the turn signals, side marker and parking light connections. These should disconnect easily when you apply pressure to the latch and pull the connection apart. The bumper cover should drop off and you can fish the wire connections through the back. If you have the factory lower fog lights installed those connections will need to be disconnected as well. Also, the sensor probe that measures outside air temperature is mounted in the lower portion of the bumper cover. Use caution when lowering the cover as not to snap that little bugger off. Set the bumper cover aside on a soft blanket so you don’t scratch up the paint.

Now you’ll need to drain the radiator. Remove the filling cap and undo the lower radiator hose that is located on the bottom edge of the radiator on the (US) driver side. I use large channel lock pliers to grip the spring clamp and slide it off the radiator tube. Wear goggles or a face mask or a divers bell because you’re probably going to get a face full of coolant when you slide the hose off the barb. Work slowly and you can contain the mess. You’ll need a bucket that can hold a gallon or so, two gallons to be on the safe side. I got around a gallon of coolant, but probably lost a quart or two while not paying attention.

To remove the radiator entirely, you’ll have to drop the entire front panel. The radiator and fan are attached to a large plastic panel. Disconnect the upper radiator hose and leave the lower one disconnected as well. You’ll need to remove the aluminum bumper too. This isn’t difficult but 10 nuts/bolts secure the bumper to the car. Here’s a shot with the bumper cover removed showing the aluminum bumper:

Remove the nuts and bolts and set the bumper aside. Next the bumper mounts need to come off. Two bolts hold the mounts in place, once removed the mounts slide off. I had to pry the mounts loose with a flat head screw driver as they were a bit stubborn. Here is a photo of the bumper mount bolts shot from under the car:

And here’s a shot from the front showing the mounts after the bumper has been removed:

Now, to drop the front panel out of the way, you need to remove two silver bolts that are just behind the bumper mounts:

And dismount the A/C freon valve that is bolted just beside the hood latch release:

With all of that junk disconnected, the radiator panel will fold down out of the way. Be careful as the air conditioner hoses will still be attached. You can lay the panel down without damaging the A/C lines, just be gentle.

The water pump is located on the left side of the engine (as you’re facing it) just above the A/C compressor and below the alternator.

To remove the pump you must first unbolt the alternator. Remove the 4 bolts and set the alternator aside. You can disconnect the wires if you need more room, but I just set mine on the upper strut mount area.

Remove the hoses attached to the water pump. You may want to unbolt the metal elbow that mounts to the engine block and connects to the coolant hose. Mine had a little bit of corrosion on the inside but was quickly fixed with some light sanding with 200 grit sandpaper. Now is a good time to replace coolant hoses if you see any cracking or if the hoses don’t feel pliable.

My old water pump showed clear signs of a leak, most likely from a failing bearing. There are two weep holes that allow for coolant to seep out and give warning before a catastrophic pump failure. The only problem is that the coolant weeps onto the top of the A/C compressor and then onto the lower bumper cover so it is difficult to see a puddle of fluid form on the ground once a failure starts. Be sure to take a peek at the compressor area every time you change your oil and keep an eye on your coolant reservoir when you check your oil…you do check your oil every week, right? One of the two water pump weep holes is visible in this picture as are the gummy blue boogers created by the leaking coolant.

The water pump should mount easily to the block. Reconnect the hoses and be sure that the spring clips are tightly fitted. Put the alternator back on making sure the ferule on the water pump mount mates into the alternator mount before re-bolting everything. I slipped the serpentine belt back on at this stage since it was easily accessible with the entire front end off of the car. Replace the radiator front panel and re-mount the A/C valve. Ensure that your hood will close correctly after mounting the A/C freon valve. I kept trying to mount it incorrectly and couldn’t figure out why the hood was smacking into the valve.

Basically now re-installing everything is, as the Haynes Manuals are fond of saying, “the reverse of removal”. Take your time, look at where everything should go and be sure leave no bolts or nuts unused. When it comes time to re-fit the bumper cover, be sure to reconnect the lights and temperature probe before you fully bolt it back in place. Once the cover is fully mounted, it’s difficult to get your hands down behind it to clip in the connectors (I know this from experience).

I started this job at about 8:30 in the morning and finished around 4:30 in the afternoon. I took my time, stopped for lunch and had to repair some broken plastic bits with epoxy…in addition to rotating the tires and bleeding the brake lines. So, your times may vary. Again, please DO NOT take on this task unless you are a reasonably seasoned mechanic or are very comfortable working on cars. The work is not difficult and requires few specialized tools but can get confusing when you’re looking at the naked front end of your car and a pile of nuts and bolts. Take your time, take lots of digital pictures to help with reassembly (trust me, this is very helpful) and consult a Bentley manual as needed. Good luck!

29 thoughts on “MINI Cooper water pump replacement

  1. I am wondering if many folk out there have experienced many water pump drive failures.
    Mine is a 10/07 Cooper, 23000klms only. Found it quite easy to replace, simply removed the top metal support for the bonnet and headlights, then lossened L/h g/box mount, removed R/H Engine support mount. Removed R/H wheel, Removed Inner mudguard.
    Then had sufficient room to remove pulley which was already floating free, still with the 3 screws in place holding the pulley attach mount. Then I removed water pump assy. I found the Pulley attach mount which has 3 screws had fallen from the Water pump shaft. Personally on viewing the corrosion on the shaft and matching it to the Pulley Mount showed it had never been fitted onto the shaft fully as on inspecting the new unit the shaft actually protruded approx 1mm through the mount. From start to finish maybe 3 hrs max.
    I am sure it could be less, can email gardcycl@hotmail.com if you have had similiar faults as I am going to forward my findings to BMW as I do know there are many claims they have dismissed. I would add some shots but cannot see how to add to this Blog

  2. Well Peter, your MINI is an ’07 which uses a completely different engine and water pump set up than mine. I know BMWs in general tend to chew up water pumps around 60k miles, if you’re lucky, so I was fine with mine kicking off at 90+k miles. I’m very surprised that yours died at only 23k km. Please feel free to e-mail me through the Contact Page and I’ll be happy to add your photos to this page for others to view. Thanks!

    brad.

  3. Thank you whoever you are for the instructions. They are SPOT ON. Without I think I would of struggled. Thanks again

  4. Very nice presentation. Excellent, in fact. The dealer wants $1000. and I have a lot of spare time. Would the same procedure work on my ’05 Cooper S?

  5. Thanks, Clarke! Unfortunately your supercharged ’05 S R53 is a different animal from my normally aspirated R50. The water pump on your car is bolted to the supercharger so I believe you have to remove the intake manifold, some of the bolts for the supercharger AND the waterpump to get at yours, which is why the dealership wants $1000…lots of labor involved.

    Check out these instructions from Pelican Parts. They do a good job of detailing the procedure for your car. Good luck!

    Pelican Parts R53 Waterpump replacement instructions.

  6. Brad – You really know your Minis! Thanks for the information. You have done a good service for the Mini community. (And for the dealer as it looks like he’s going to get my 1000 bucks!!!!)

  7. Thanks so much! I am bookmarking your page! I have had a leaky water pump for a while now and Midas told me the took to get the water pump off my 2009 standard MINI cooper hardtop was $300… after reading your instructions, there was no mention of “special tools”. I am looking for a mechanic around my area that works on MINI’s…but they are few and far between… so, I guess it is time to go see the dealer…boo

  8. Heather,

    A 2009 MINI will be different than the one I detailed above as the car was totally redesigned for the 2007 model year. I’ve not worked on an 07 and later MINI so I can’t say if it needs special tools. However, even in our little town there are plenty of import car shops who would be willing to work on a MINI. Try these links and see if there is someone in your area:

    http://www.minirepairshops.com/

    http://soopercooperinfo.com/lindaminiinfo.html

  9. I like this,when I saw pics of your mini and your presentation there was no way I cant congratulate my yonger brother and I for successfully Replacing a clutch kit on my mini Cooper.

    Looking forward to changing the water pump as well.

  10. Hello! I have a 2003 Mini Cooper Hardtop (base model). It had the water pump replaced in Feb 2007 under warranty, another replacement in Dec 2010 paid for by me, and now the dealer says it looks like it isn’t working again in March 2013. This seems odd that a 10-year old car with 96,000 miles should need a 4th water pump, yes? Any suggestions for me and how I should handle this?
    Thanks!
    -Heather

  11. Heather,

    I can’t comment as to how long a water pump should last. Certainly you shouldn’t be on your 4th one by now. BMW water pumps, especially since the mid 90s, have been known to fail with regularity. Usually 60k miles is all you can ask of them. I would be certain that your dealership is installing quality parts. I purchased my water pump from Promini.com and it was about $270 as I recall (they are now $165)…not cheap but it wasn’t a junk aftermarket one either. I have almost 140k miles on my MINI and have only replaced the water pump once. The early 2002/2003 MINIs were known to have more problems than the later 04-06 models. You may want to search the North American Motoring forums for any further info on early build water pump failures. I’d think after your first failure you’d have received an upgraded water pump if one was available for the car.

    What issues is your MINI having? Is it leaking coolant from the lower passenger side area? If so, that may be a water pump issue. If it is leaking from the middle of the car, it could be your thermostat. If you are hearing odd grinding or squealing noises at start up, you could have an idler or tensioner pulley that is causing problems and causing pre-mature water pump failure…especially if your tensioner is too tight.

    Secondly, I personally would not take this job to the dealership. Most of the work is in removing the body panels, which just about any repair shop should be able to do. The actual work of removing and installing the water pump is very easy. There are no special MINI-only tools required. If there is a local, independent European shop you trust, I’d go with them and spend less per hour on labor.

    Good luck!

  12. Thank you for your advice, Brad!

    Basically my car overheated the other day, so I had it towed to the dealer and they suggested a water pump. Once I pointed out that the car had already had one put in recently, they downgraded to a thermostat. They put that in for $54. .As they should, considering they put a new DME in my car within the past few weeks and they know I am already fuming. My father is now questioning the competency of this dealer. I’m wondering where I can find a car mechanics class to get the basics and be less ignorant. :)

  13. $54 is a good price for a thermostat replacement. Good luck with finding a class, I’ve had to learn the hard way by breaking and fixing things! Keep an eye on your temp, coolant consumption and oil to be sure you didn’t damage the head gasket when your car overheated!

  14. i have an 03 mini cooper s and it keeps over heating. the coolant level is fine but when i squeeze the hoses near the radiator they feel very empty could this b because of a bad water pump? if so how do i change mine? i checked the oil as well and its at the correct level and its clean no milkyness.

  15. Chris,

    I’d check your thermostat first. The R53 Cooper S is a little different than the standard R50 Cooper as the thermostat on the S mounts to the water pump and not the cylinder head. But the principle is the same, the t-stat should open as the temp rises and allow coolant to flow through the upper hose. If the upper hose feels empty before the car gets up the temp, that is normal. But, if the car is warmed up and you don’t feel hot coolant flowing through the upper hose, the t-stat may be broken and not allowing all the coolant to flow and thus allowing it to heat up over the normal operating temperature.

    The 03 Cooper S has the waterpump that is driven off the supercharger. In order to even get a good look at the water pump and the t-stat you have to remove the airbox, throttle body and intercooler. So, it could be hard to tell if it is the waterpump that is causing the problems. In either case, if you aren’t seeing a leak, the pump is probably fine…though if it car has high miles, a water pump replacement might be in the near future anyway as you can’t expect more than 60-70k miles out of one usually.

    Another possibility is that you have air in the system. I’d top up your radiator directly by removing the cap with the engine cold. Fill up the radiator and then turn the car on for just a few seconds to let the coolant circulate. Then refill and try it again. You may be surprised how much coolant the radiator may accept. Give the upper radiator hose several good squeezes while filling the radiator to help remove air bubbles too. You can also turn the plastic bleeder screws to check for air…but be careful, they are plastic and prone to breaking (at least they are on the Cooper R50)! Gently open them a small way. If air comes out, let it leak until you see coolant flowing then close it up. It may be hard to access the screws on the Cooper S, though. I’m not quite sure where they are in relation to the intercooler so they may be hiding under all that stuff.

    Good luck!

    brad.

  16. Just wanted to give you a shout and say THANK YOU!! I am currently struggling financially and could not afford the $600-$800 the mechanics wanted to replace the water pump on my 2002 Mini. Having never done much more on a car than change the oil, I dove in with your instructions and after about 8 hours work I am back on the road. Total expense was $197 for a water pump with rush overnight shipping. After this experience I am ready to tackle all the other little problems on the car has like bad engine mounts, a broken strut mount, and replacing the struts. Thanks again for your help.

  17. Thanks! I’m glad you were able to fix it Mine took about 8 hours too so you must be as good of a mechanic as I am…but that isn’t saying much! Cheers!

    -brad.

  18. Thankyou for the great technical write up on R50 Coolant pump replacement
    my car is 09/06 Compliance with 155,000Km since all the removal procedure involved with this job do you consider it wise to replace the belt & tensioner as well?

  19. Hey Paul,

    The belt is easy to replace any time, you just have to pull the wheel and wheel well insert. I haven’t replaced the tensioner yet in 150k miles. Again, it’s easy to get to without having to take the front of the car off as with the water pump.

    Cheers!

    brad.

  20. I have an ’03 mini that has had an over heating problem for some time. Mechanic has replaced the thermo and water pump.. now saying that the turbo is causing the over heating and needs rebuilt? is this a possibility?

  21. Duke,

    Your ’03 MINI has a supercharger, not a turbo. It is definitely not uncommon for the superchargers in the R53s to need rebuilding, some after as little at 60k miles. If the supercharger is overheating, I suppose it could cause other heating issues with the car. Check out the northamericanmotoring.com forums and do some searches for “overheating” and “supercharger” and see what comes up. I’m not familiar with the Cooper S models in this respect as I own the standard non-supercharged model. But, I do know that the supercharger drives the water pump in your car so there is a direct correlation between the SC and the cooling system. Good luck!

  22. Hi, I own a Mini Cooper S R53 2004 129000 miles, never had a problem with the car apart from new cluthch at 112000 miles, I have always changed the oïl and filter every 10000 miles with a top quality oïl (Mobil1) I have noticed recently a rattling noise coming from around the supercharger/waterpump area. The goes well recently drove 3000 miles averaging 100 mph and I am not losing coolant. Could it be the waterpump ???

  23. Stuart,

    It’s possible that it is a bearing in the water pump and you are only slowly losing coolant. Although I would probably guess that a bearing in your supercharger is starting to rattle. If you’ve not replaced the supercharger at 129000, you are probably pretty lucky.

    Does it sound like this: https://www.youtube.com/watch?v=v0YRQBlW7Mo

  24. Pingback: Mini Cooper Coolant Leaks | Volkswagen

  25. i have 2003 mini cooper s the temperture gauge goes straight to middle when just started about 5 minutes .it also has fluid in the passenger side foot well .any ans to this

  26. Fluid in the footwell is probably a leaking heater core or heater core connecting hose that will require you to pull out the center console area to inspect. You may also have air in your coolant system due to the leak and that can cause the temp gauge to read incorrectly. You can fill the radiator up with coolant with the engine cole and leave the cap off then start the engine. While it’s running squeeze the upper coolant hoses to remove air. If the coolant level in the radiator goes down, you’re removing the bubbles. But, it will all be for nothing if you don’t fix the leak under your dash.

  27. I have a 2008 mini cooper and it gave me the over heating warning one day then sat for a few weeks, I drove it twice since then and didn’t go far but no warning lights or any troubles. Leaks fluid not sure where it is coming from though. Any ideas I don’t want to get ripped off by a mechanic and unfortunately I am not the mechanic type but am open to any insight. Thank you.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>