Working on a Mini Cooper is a bit of a pain because, well, it’s “Mini”. There is no space for anything in here, including to replace the auxiliary belt – the one that drives the alternator, AC compressor and power steering pump. But, it’s a job that’s got to be done so let’s get at it.
Normally you’d use a special tool to lift the belt tensioner out of the way, but I don’t have one and I didn’t end up needing it. Doing without it was a bit harder than with, but not by much so let me run you through how I got it done. First things first, you’ll need to position a jack under the engine, ideally with a block of wood between the jack and the engine so you don’t damage your oil pan. Pump the jack until it’s slightly raising the car.
Next you can remove the driver’s side engine mount. It’s just 4 bolts and one nut. The bolts are 16mm, and decently tight, also the front bolts are slightly obstructed by wiring and lines so be careful to not damage them when loosening especially the most inboard bolt there. The nut on top of the engine mount is an 18mm, and again fairly tight. Once all four bolts and the nut are out you can also remove the grounding strap’s 13mm nut – careful here as there is a loose bolt on the underside that will just fall out when you remove the nut! Then you can lift the engine mount out of the way. You might also want to fully remove the grounding strap for better access.
Once the mount is out of the way, you’ll want to grab a 3/8ths drive ratchet, along with a 3mm allen key, then lower the jack so the engine drops down. With the right angle, you should be able to fish the ratchet into the square hole in the tensioner arm – it might take a minute to find the right angle for the engine and the ratchet, but once it’s in you are set. You can then pull up on the ratchet so the tensioner is fully retracted – this is where the allen key is handy. Slide it into the small hole at the top to have it act as the locking pin.
With the tensioner locked out, you can then remove the ratchet and get to work peeling the belt off. I found the main task was to just lift it off of the alternator pulley, and with a mix or wiggling and force I got it off. It’s at this point I want to mention that before taking this off I actually drew myself a diagram of how the belt was arranged so I’d know how to put it back on later. This is the obviously professional quality diagram I created – our Mini is the model with air conditioning, but if you don’t have that you’ll likely have the same layout but with a shorter belt and you won’t have the AC compressor down at the bottom right. The belt I’m using here is a 6PK 1033 – meaning it has 6 ribs and is 1033mm long.
Getting the new belt on is a bit of a pain, but I started with hooking it around the AC compressor, then reached in from the across the engine to pull the belt onto the crank pulley and under the tensioner, then had a fight with it to lift it onto the alternator pulley. After a scuffle, I won and got it in place. I then used a pry bar to release a tiny bit of pressure on the tensioner arm to be able to remove the allen key then let it down. Now my tensioner is on it’s way out so I will be changing that out when I get the chance – I already have it’s replacement – but one of the bolts has already snapped and we need the car to still work so that’s a task for another day.
Of course, you’ll need to get the engine mount back on, so pump the jack to lift the engine back up, then place the mount back in. You might need to give the engine a bit of a pull to get the bolt holes to line up properly, then you can thread in the bolts. I’d tighten those up before installing the nut on the engine mount itself. Don’t forget the grounding strap either! Finally, make sure to start the engine and make sure the belt is running properly, then that’s it, belt replaced with no special tools!