Mini Cooper S JCW

I had for some time been researching the purchase of an additional “toy” car – something to tinker with and drive just for fun. I currently have the venerable Land Rover for all normal running around but it could never be described as fun. Following my usual form I spent far too long reserching various possibilities, all involving car purchase in the UK – as there is much more choice and they are usually a lot cheaper. Finally set my sights on a new generation Mini Cooper S, but preferably one that had already had some “fast road” preparation work done. I came across one in the North of England not far from where my brother Chris lives and called him to ask his opinion. He probably later regretted it but said “Shall we drive over and get it for you”. A phone call and quick haggle later and the car was mine – sold sight unseen. Chris just needed to go and collect it and it was much further away than we had realised…. It stayed parked in his drive for a while until I arranged for Richard PERCIVAL to collect and deliver it to France. He did a great job and I heartily recommend him.

This is a track day video the previous owner sent me to show what the car does best..

Mini JCW Oulton Park Track Day

Initial check over shows some things need doing (but having things to play with was part of the plan) and it is a 2005 car.

Rear discs are rusty and will need replacing. Not sure how it got through the MOT – unless it has been standing for a long time since then.

Front suspension towers have mushroomed, which is a common problem especially with stiffer suspension.
Long list of detail things that need doing / fixing…
Oil and filter change (just been done but I’ll do again)
Headlight switch to LHD
Loose headlamp cover
Missing wheel centre
Suspension components quite rusty – leave or paint?
Change coolant
Change supercharger oil – quite a big job but needs doing about now especially as this one has worked hard.
Precautionary change of water pump and thermostat at the same time
Change gearbox oil
Rust spots on boot lid
New bettery ? Engine cranks rather slowly

Overall the car seems completely genuine and as described – which is a bit of a relief.


I have suddenly redicovered my interest in driving. Since moving to France 13 years ago the car has been a form of transport for getting from A to B in comfort and safety and as economically as possible. I don’t overtake or go round corners very fast – the Land Rover is a bit like a truck and not to be rushed.

The Mini experience starts when you fall down into it rather than climbing up. It has the optional and very expensive leather bucket seats which wrap round you so you don’t move about. It is a small car – no room for a passenger behind my seat, could fit one behind the other front seat. The performance is more like a motorbike than a car. Cornering is flat with so far endless grip. The ride is incredibly stiff – bumps on country roads throw you out of the seat. Designed for smooth roads or the track. Controls are heavy – heavier than the Land Rover. They are matched in that they are all heavy – steering, clutch and brakes but it means a bit of adapting to. Performance seems better than my Elise and grip also very good but the feeling through the steering and seat of the pants is nowhere near the telepathic levels of the Lotus. Heavy control weights don’t help. I expect I’ll get used to it.

The driving experience does put me in mind of my bike – I’m looking for excuses to drive it and every drive is an experience = fun.

Shiny black paintwork

So the bodywork and interior are in excellent shape. In contrast the underside looks like it has spent the last 12 years in salt water

English Winter Salt

This is going to need some work – just hope this is mainly confined to the chassis members and not the body work. Don’t want to be welding my new car just yet. Rear discs

Rusty Rear Discs

The deformed strut towers. The strut top mount is retained by three bolts, which should all be parallel – which they are not !

Just been through all of the service documentation that came with the car and put it into a spreadsheet that I can add to as I do stuff.

All seems to stack up. The previous owner obviously just had it as a track day toy. In the two years he owned it he only did 2,000 miles and spent a lot on performance, brake and suspension upgrades. Especially the brakes. Started with new pads on existing discs, then switched to Brembo discs and pads, finally changed to Nitrac discs with Mintex pads.

New shocks and lowered springs were fitted at the end of last year so I assume the strut tower mushrooming has happened since then as they would not have been able to fit new shocks with the towers as they are at the moment. Bouncing off curbs on the track (as seen on the video) is obviously the cause.


New rear discs and pads ordered
New front strut top mounts ordered
Also ordered re-inforcing plates to go under the towers to combat the problem
Large tin of hammerite for painting the rusty bits !
Front wheels cleaned up – insides were corroded so sanded down and painted.
Front calipers cleaned up.
New battery fitted.
Rear wheels cleaned and painted.
Rear calipers cleaned
Rust spot on boot touched up – doesn’t look great but should stop it getting worse

Waiting for all the bits to arrive…


The boot is tiny, the rear seats are useless as the front bucket seats take up all the room and don’t tilt/slide very easily. Rearward visibility is quite poor…
Step 1 was to remove the rear headrests – some improvement in visibility
Step 2 remove parcel shelf and fold down rear seats – massive improvement giving a useful load space that is easy to access
Step 3 remove rear seats, belts and all rear trim

Improved Load Space

It makes a very quick road car (don’t try this at home)

Out for a drive with Georgina

I had told myself that the rear of the car would be easier and started on the job confident of quickly getting it done. But it was much harder. The rust scraping is a horrible job. Painting is more satisfying but messy as it is upside down. I did all the scraping and some of the painting. Hope to finish it off today.

I was using a wire brush attachment on a drill to get the worst off. Stupidly I was using the trigger lock on the drill and doing some bits one handed. The brush caught on a metal edge, jumped out of my hand and set off jumping across the floor – until it pulled the electrical plug out of the socket. Heeding this warning I continued more carefully only using two hands and the trigger. Still managed to wrap it round some pipes under the car and snap one of the brake pad wear indicators. Doh!
This made me even more pissed off about doing this job.

The main subframes and suspension components looked terrible but were probably OK. Over here I don’t expect the rust to get any worse and the metal sections are thick. The body work on the underside is more of a concern as it is only thin sheet metal. Anyway I’ve nearly done it all now. Prefer tinkering with bits and pieces to this job – I made up a little dipstick to check the water level which was much more satisfying. Doesn’t seem to have lost any more water.

Job list still to do:
Reglue hedlamp cover
Change oil and filter
Change gerabox oil
Fit new rear discs and pads
Fit new strut top mounts and re-inforcing plates and flatten mushrooming
Fit new header tank, replace coolant
Supercharger oil change (maybe replace water pump and thermostat at the same time)

Strut tops now done. Watched several youtube videos and read forums on doing this job – no Haynes manual here – does anyone use them anymore?

Managed to almost do it without using a spring compressor – use the weight of the car to compress the spring. Car on axle stands and two trolleys jacks to lift the struts. This was just as well as my compressors are a bit big and wouldn’t fit in (OK on the Land Rover).

Got the old mounts off easily and panel beating the tops back into shape was quite easy too. Getting the new tops and plates into place took ages. Kept running out of ideas and stopping for a cup of tea to sit and think about the problem. Then start again with renewed thoughts. Seems to work for me.

Two problems – getting the mounts and plates into place with the struts still on the car, filling the space where the mounts have to go and spring uncompressed. Eventually did one side but couldn’t manage the other. Had to resort to partially comprsssing the spring with a compressor to get it in.

Second problem was on pushing the strut up into the mount, the strut top is a tight fit in the bearing and simply compressed the damper rather than pushing through the bearing. Mole grips on the damper shaft helped with that one. Once though it was just tighten up the bolts and done.

New Brembo rear brakes arrived and fitted yesterday. Calipers came off no problem. Disc held on by a big screw which wouldn’t budge with an impact driver – usually works. I have drilled them out before but this time I had an angle grinder with a metal cutting disc and cut the head off the screw. Disc was still held on with rust but came loose with a bit of hammering. Fortunately I didn’t have to remove the caliper carrier (which has been necessary on all the other rear discs I have changed). This was just as well as the bolt heads were rusted and probably wouldn’t have come undone and too inaccessible to cut off. Cleaned up and some of the hub painted and back together.

Old pads and disc in a real state but I suppose there was no lack of friction, just wouldn’t have lasted very long. The rear discs don’t do much on these cars – even highly modified cars often run std rear brakes. The previous owner had changed the front brakes three times in an attempt to find a solution that didn’t fade but at the rear he only fitted high performance pads. You have to assume that when the garage fitted these the disc was in reasonable shape. But according to the records that was June 2017 so I’m not so sure.

Air filter was on the maintenance list but a lower priority as I didn’t expect any problems. Turns out that the original paper element filter had been upgraded to a racing-type foam filter These need to be washed out with solvent and then re-oiled. I used petrol and a hair dryer to make sure the petrol had gone before re-oiling. I actually have the proper filter oil for the KTM.

The air box has a supplementary cold air intake flap that opens above 4500 rpm and increases air flow and induction/supercharger noise at high revs. Part of the works tuning package (as are the pops and bangs from the exhaust on the overrun). Yet another mod had been carried out in that the flap had been removed allowing it to run open all the time – known as a “flapectomy”. But the actuation mechanism and vacuum cylinder was still in place so I have removed them as well.

Starting to wonder about the front suspension again ! The tops of the struts look very high inside the new top mounts. Maybe because I have panel beaten the area back so that the strut appears higher – can’t be that the new rubber mounts have failed already – on both sides? Seems very unlikely. I’ll have a closer look the next time the car is jacked up – probably soon as I want to flush and change the brake fluid – when did anyone last do that? Harder to see the top of the mount now my re-inforcing plate is in there.

Reading more about suspension mods it seems that running shorter springs with standard dampers is mainly a track mod and works great on smooth roads. It makes the setup very stiff and appears that the car is running on the bump stops a lot of the time. Not as bad as it sounds as BMW designed the progressive bump stops to be part of the suspension – the car always having had very short travel. Cutting down the existing bump stops or fitting shorter ones can help. Other options are changing to a racing top mount – this removes the rubber and really stiffens the top (and allows camber adjustment) – probably the best route if my new mounts are damaged (can’t be?). Next step would be what are called coil-overs which is a replacement of the spring and damper at each corner. All good fun.

As one of the headlight washers is held together with glue and I don’t need them I have removed the fuse for the washers and will look at removing the washers themselves at some point. Shouldn’t be an MOT failure but we’ll see.

Got the air filter back together, having left it overnight for the excess oil to drain away

Jacked up car and got the wheels off to flush/bleed the brakes which with Gij’s help was surprisingly easy.

Managed to find a spray can of car body underseal and was able to use that to cover the rusty parts underneath that my paintbrush couldn’t reach. Now pretty tidy under there.

Side project was to look at the suspension and mounts a bit more scientifically, so I took some measurements. The rubber in the top mounts is deforming by 15mm under the weight of the car, which is probably reasonable. The mounts look OK, some possible minor cracks but could just be the new paint cracking off the rubber. So conclude that the top mounts are OK. However, the total available suspension travel is 90mm at the front – amount of travel before the top of the damper tube hits the bump stop. Under static load the amount of travel used up just supporting the weight of the car is 100mm! So it is actually sitting on the bump stops. No wonder it feels so stiff and bouncy. OK for the race track and smooth roads but not great on normal roads and when charging round a bumpy corner?

Need to think about that one some more…

Reading the many forums it appears that this is a common first suspension mod, with most people then moving on to “coilovers” – this is a replacement for the spring and damper as a combined unit but with adjustable spring platforms so you can adjust the ride height but still retain some suspension travel.

Still on the list of jobs..

– Need new front indicator (lens cracked and reflector corroded) – on order
– Supercharger oil change – got the oil but it’s a big job
– Also look at changing the water pump, thermostat and housing at the same time
– Coolant change – do at same time as above
– Header tank change – ditto but I do have the new tank
– New tyres – still OK for the moment but will need doing (non runflats)
– Couple of missing bolts for the centre console
– Think about the suspension conundrum – keep driving it to form a better opinion

New sidelight/indicator units arrived yesterday – reason for these is that one of the original lenses was cracked and reflector corroded. These are LED ones which were cheaper for a pair than one OEM replacement. Tried to do it without taking the front bumper off but not possible because the fog lights underneath the indicators have been removed and brake cooling ducts fitted. The ducts are retained partly by fixing to the back of the side-lights, so it was bumper off. A job I was not looking forward to due to rusty fasteners, but will have to come of when I strip the front end to do the supercharger oil. Not too bad in the end and satisfying to refit with better fasteners. I had to cut two off with my dremel (fantastic tool for this job) and managed to make up replacements. Could do with a bigger haul of spare bolts/nuts/washers/self tappers.

Revisited the suspension issue – you can tell I am hooked on this. Standard car has 30mm of travel at the front before engaging the bump stops – this has lowering springs (shorter and stiffer) that drop the car by 30mm ergo it rides on the bump stops all the time.

The plan I have come up with is to buy two non runflat tyres of the exact same type as the current runflats: Pirelli P Zero, put them on the front and put the run flats on the back. Only two of the four current tyres really need replacing (they were on the front for the track days). Opinions differ on mixing runflat and non runflat but I believe no worse than having different brands front and rear (these will be the same tread pattern etc). The idea will be to see what effect the new tyres have on the suspension/ride – do they make it more acceptable? Quite like the idea of upgrading to coilovers at some point and playing with ride height/damping rates and suspension geometry – but not just now.

Next major job is the supercharger oil, but need to work up to that one and also need more bits ready for the job – water pump, thermostat, housing, seal.

Change of plan on the tyres. I’ve bitten the bullet and ordered four new non-runflats, which was the plan when I bought the car, but seems a shame to replace tyres that still have plenty of life left in them. On the other hand as I enjoy charging round corners in it having four good tyres is probably sensible. Michelin Pilot Super Sports – 133 Euros a pop. The Pirelli P Zero is runflat or non-runflat are 115.

I am starting to lose enthusiasm for all the car DIY and am more interested in driving and “tinkering” – the suspension has my interest at the moment for example. In particular I am having second thoughts on some of my preventative maintenance plans.

– The tyres will be changed and I will then assess the ride, before going any further with suspension. Possible future work could be looking at changing the bump stops on the existing setup – either buy some special ones if available or get some STD ones and modify them. Next step might be to go for Biltein B8 dampers with the existing lowered springs. The front dampers delete the existing bump stops as they have their own internal bump stop – they are shorter units designed to work with shorter springs. A bigger step would be to throw away the current springs and dampers and go for coil-overs. We’ll see..

– Will fit the new jacking points I have receved

– Will repaint the calipers – as much to protect them from corrosion as anything – but yellow looks pretty cool through the red wheels ! This counts as tinkering.

– Find and fit some replacement centre console bolts – a couple of the existing ones missing, but it doesnt seem to rattle despite the bumpy ride so why bother ?

– Get a tyre sealant can and find somewhere to store it for when I get the non-runflat tyres

– Get a fire extinguisher and fit that somewhere – tinkering.

– The biggest remaining job is the supercharger oil change, which I would like to avoid but reaaly should be done. There are plenty of horror stories of gears running out of oil and seizing. No maintenance specified by BMW but 75k seems to be advised by many. This means taking apart the whole front end of the car and draining the radiator – so it makes sense to change the coolant and fit my header tank at the same time. I bought that when I thought I had a water leak and they are renowned for splitting. I was also going to replace the following at the same time :
— water pump
— thermostat housing and seals and thermostat
— crank position sensor o-ring
I am now thinking why bother ?
Once I have had the front end apart I will know how to do it next time and it will be easier.
I don’t have a water leak so these bits should be OK.
– I was going to completely remove the
s/c in order to drain the oil, but it is a lot less work to leave it in situ (no special tool needed to remove the belt). But in this case you can only syringe out some of the old oil – but my concern is not really the condition of the oil as the quantity remaining. The high speed s/c gears should be running clean and not really contaminating the oil although I suppose it will degrade over time.

Supercharger – the front plug is just accessible and I probably could undo it and drain/top up – but having not done it before I’m not sure what to expect. So current plan is some time next week to put the car into what they call “front end service mode”, which involves taking the front end off to get good access to the front of the engine. Should only be 1-2 hours work but I know some of the fasteneres will be rusted and maybe need to be cut off and replaced. I did this with the bumper to fit the indicators and it will be much easier to do a second time. Will also drain the coolant and fit the expansion tank.

Once everything is exposed I should be able to do the front S/C plug without too much trouble. Not sure about the back one though – if it can be done in situ great, if not Ill have to asses what else has to come off and what replacement gaskets etc I’ll need. Maybe order those for delivery while I’m away in the UK and put it back together on my return.

Front end stripped for supercharger access

A good afternoon’s work yesterday. Needed to take to intake horn off to access the rear fill plug, but it’s a bas$$$d to get off and back on without breaking anything or creating any leaks. Picked up some tips from YouTube and forums and did it by unbolting a bigger assembly including part of the inlet manifold. Was going very carefully to avoid breaking anything. Two vacuum pipes come out of the duct towards the engine with no space to access them for removal or re-insertion, but long nosed pliers saved the day.

Fill plug came undone easily (it has an o-ring), I unscrewed it slowly to check if any oil would come out – hoping but not expecting any the same as I did with the front, but oil did start to leak out and looked quite clean. So did the plug up again quick as I can’t get any more in there. Then gradual cleaning and re-assembly of the parts. Also took out the TDC sensor with O ring from the front of the block that has been leaking oil. Put back in with some sealer and will keep an eye on it. Should have ordered a new O ring (a special one).

More or less back to where I started yesterday – did swap over the coolant header tank as well. Now need to put the front end back together and fill/bleed the coolant system. Will take time as I need to remove some damaged fittings and find replacements.

The front S/C plug I can probably now access without any dismantling and with my syringe and pipe I can top that up OK. The rear one I will assume is OK for the time being.

When the water pump or thermostat pack up I will have to take it to bits again, which will be a lot easier. At that time I will look at changing to an electric water pump. This removes the need for a drive from the back of the s/c.

Actual job list on the car pretty much completed, can get on with some tinkering and other stuff now.

– Touch up / repaint calipers when paint arrives
– Low speed fan fix when resistor arrives
– Ongoing thinking about the suspension – bump stops/dampers/coil overs
– Find somewhere to store the compressor and puncture repair kit

Only took a month !