Build thread: The Grotty Little Mini Cooper S

I've always, always wanted to build a $200X challenge car. I live in Colorado, and it's a loooong drive to Gainesville in October, so I'm not 100% sure I'll make it, but I'm building this car and keeping records so I could.

I used to autocross super-cheap, rusty, modified Datsun 510s in high school in the 90s, but I haven't driven an autocross this century.  For the last couple of decades or so my projects have consisted of cheap and fun daily drivers ('94 Celica ST, '98 Subaru Outback,' 04 Golf GL) for myself and my high schoolers, a couple of old motorcycles, and my 1981 Vanagon Westfalia that I swapped a Subaru engine into and did all kinds of mods.

So, I freaked out when I found an ugly, sad 2004 Mini Cooper S with a 6 speed on Craigslist for $800!  The PO never changed the oil. The timing chain tensioner died, and the timing chain started making bad noises until it stopped running. The PO dragged it to his 87-year-old grandfather (a super-nice guy who had worked on cars his whole life) to try to fix it. He bought a new timing chain set, and started taking it apart before he realized it was way beyond his skills and physical abilities to fix.  I bought it from the grandfather. Here are crappy pics from the CL ad:

I was stoked when I saw the JCW badge on the grille, but it turns out it's just a normal "S" with a poorly-bolted-on JCW badge.

In addition to the new timing set, it came with a second set of floor mats, 3000-miles-old tires that look new, and the PO got it aligned with the tires (and the shop hadn't complained that the front end was too hosed to align properly or anything)

On the other hand, when I got underneath and started working on it, I saw it had a ripped outer passenger CV boot.  I decided I'd worry about that later.

I got the timing cover off and saw that the timing chain had taken chunks out of the back side of the front cover / oil pump, so I got a new, cheap front cover / oil pump from ebay.

It came with a new timing set, but pulling the crank sprocket was an incredible P.I.T.A! I first tried getting it with a rental 3-arm puller from AutoZone, but it was so tight in there that the puller would just pop off.

I bought a little bearing spitter and set up with a puller and a scrap of old timing chain around the sprocket to give it something better to grip. I had to use slightly smaller bolts with the splitter so I could angle it into position:

I cranked and cranked on the puller until the bolts bent and teeth started popping off of the sprocket:

So I ended up grinding that bastard off along the keyway with my Dremel with a tungsten carbide bit (and managed not to damage the crank) It only took about 10 minutes and popped right off:

I put some rare earth magnets next to where I was grinding that caught a lot of the metal shavings, but they still went everywhere and stuck to the oily face of the block. I washed the face off the block off with brake cleaner and then pulled the pan to get the metal shavings + bits of timing cover out of the engine.

The new timing set and cover went on with little drama.

Pulling the pan was more hassle than I'm used to because both the A/C compressor and a motor mount bolt to the pan (so I had to loosen the whole radiator support to access the AC compressor bolts)

Here's the fun stuff I found in the oil pan (all neatly deposited in a pile right below the timing chain, so I hope that means it wasn't driven too much after the destruction) Keys for scale...mmmm gliiitery...:

I got the pan all cleaned up with brake cleaner and re-installed:

I crossed my fingers and ran a compression test...it was GOOD! No bent valves!! 

So, I buttoned it up and went to drive it for the first time!

It ran freaking awesome, especially given the crappy ancient gas that was in the tank. It felt SO FAST! The supercharger whine is so great and addictive! After using the brakes enough to scrape off the copious surface rust they had accumulated over the last 18 months, they felt great. It felt like it handled really well!

<Angels singing>

So I loaded up my wife and 2 kiddos and went for a drive (which, incidentally is my entire Vehicle Rescue Crew). My wife flogged it and loved it. My 17-year-old son flogged it and loved it and drove us up into the foothills with a bunch of crazy fun twisty hilly roads and no cell reception.

Then the clutch went to the floor. 

"No biggie" I say...I've driven home sketchy cars with no clutches tons of times! So I pop in the driver's seat, crank it in first, and it kind of fires up but doesn't really like running at 500 RPM and stalls. Try to restart it...and nothing. The battery is weak from sitting forever, and Mini's BCM cuts power to the starter circuit if the voltage is too low, so they either crank super strong or you get nothing.

Crap. No clutch. No crank. No cell reception, and no one to come rescue us even if we had cell reception...

So, we get out, and as a family push it a zillion-point turn (Austin Powers style), so we're pointing downhill. (thinking I'll try rolling and trying to slam it in gear to push start it). Luckily a nice guy in a beat up old 4Runner came by and gave us a jump start (I had jumper cables, of course!). It fired right up.  I rolled down the hill, slammed it in gear, and drove in 2nd between 5MPH and 45MPH until we got into town and got stuck at our first light.

I was able to use the syncros in the transmission to coax the car to walking pace to get going and then slam it into gear to limp home. Not the best for transmission longevity, but we made it back!

It turns out the PO had snapped a clutch slave cylinder mounting lug off the transmission (which is super-common on these cars apparently), and the stock, plastic slave cylinder flexed when held on with just one bolt and failed.

The coolest part, though, was that I got mad respect from my 17-year-old and wife about staying calm and collected and driving the car home like that. My 17-year-old went to a concert that night and told all his friends, and now when they see me, they start the conversation with "I heard about your drive home...woah.". Mad respect from teenagers is worth a lot.

Very cool!

I was the first to bring a MINI Cooper S to the Challenge, and I am thrilled to see the prices continue to drop and more show up!

I didn’t do much to my car- underdrive pulley, new tires, and some good adjustable top mounts. I also opened up the intake and exhaust, and shed what simple weight I could (while still wanting to return it to the street). Placed 2nd in the Autocross.

BTW, they respond really well to reducing weight up high. I had a busted windshield and (temporarily) replaced it with Lexan. I could feel the difference instantly from the driver’s seat!

Good luck!

In reply to Veloandy :

Nice score...great start.  Street cred for dad.

Welcome to the hive.  Do try to make the challenge.  Its a hoot.  You look headed for winning the Gsstropod class!

In reply to SVreX :

What you were feeling was wind leak from your makeshift windshield.

In reply to SVreX :

Thanks for the warm welcome! I figured Minis are pretty BA auto crossers out of the box. If I make it look OK, hone my driving skills at a few local auto crosses, and add drag-race-oriented mods, I might do all right!

They respond really well to reducing weight up high

Totally good to know! My headliner is sagging and my car has the dual panoramic sunroof. When I get the headliner out, I’ll have to see how hard it would be to temporarily remove the sunroof assembly and glass!

I had a busted windshield and (temporarily) replaced it with Lexan. I could feel a difference instantly from the driver’s seat!

Well my windshield is broken! Did your Mini get flexier without windshield glass? I was shocked by how the roof and A pillars turned to jello on my high schooler’s mk4 Golf when my windshield guy was almost finished breaking the old windshield seal with his chisel/scraper/electric jackhammer tool. Even he commented on how integral the windshield was to the structure of the car.

It turns out one of the clutch slave cylinder mounting lugs was snapped off my transmission, causing the flexy plastic stock slave to fail. I repaired the mount using a $10 stainless steel exhaust flange from Rocky Mountain Westy.

I replaced the clutch slave with a steel Chevy slave cylinder (instead of the flexy, more expensive, failure-prone stock plastic one), built/ran a new steel hydraulic line to it. 

At first I mounted it with the bleed nipple low and accessible...but of course it doesn't work to bleed air out of the lowest part of the slave (duh in retrospect). So I flipped the slave so the bleed nipple is on the top, kissing the transaxle, and built a new hard line to it. Bleeding it was a pain because I had to remove the slave to put a bleeder hose on it. Whatever, I FINALLY got the whole mess bled properly. It’s rock solid now: 

BUT

Now clutch is slipping! Argh! I made double-darned sure the Chevy slave is retracting far enough. So I need to do a clutch. I must have finished off the old tired clutch driving home going 5mph-45mph in 2nd.

It has a dual mass flywheel, and it’s unclear if it can be be turned, so I ordered a cheaper, lighter single-mass flywheel and clutch conversion kit.

Doing a clutch on that car is non-trivial. I have to pull the front end totally off, drop the front subframe, and it’s easier to reach the trans mounting bolts if I remove the supercharger. With the supercharger out it makes sense to change the supercharger oil, and the water pump mounts to the back of the supercharger so I might as well replace the water pump and thermostat too. Since I’ll have the hoses all off, I might as well replace them all with silicone hoses. It has a ripped CV boot, and the axle will be super easy to access with it all apart.

Oh well, I wanted a project...So I ordered $400 of parts last night.  I still have $615 left in the $2019 budget for a windshield (maybe), minor aesthetic fixes and performance mods. 

Now we're up to date! It might take a week or two before I have any subsequent real updates. Hopefully it goes well!

Sounds like an epic adventure in the making!

I have read this thread a few times and this line still has me shaking my head.

"and the stock, plastic slave cylinder flexed"

I guess they don't make them like they used to.

noddaz said:

Sounds like an epic adventure in the making!

I have read this thread a few times and this line still has me shaking my head.

"and the stock, plastic slave cylinder flexed"

I guess they don't make them like they used to.

Haha...yeah...or maybe they didn't make them to be held on by 1 of 2 bolts :-)

I did the clutch on the Mini! It took a ton of disassembly. I pulled the supercharger off to change the oil in it and did a 15% pulley because it wasn't ever going to be more accessible. Here's a pic of the SC on my work table with the old pulley on top of the new. You can see from the distortion on the old pulley that it wasn't happy about coming off!

The clutch was weird. It had new-looking gear oil in the transmission. Someone had previously swapped in a single-mass flywheel. The pressure plate looked pretty new. The flywheel side of the clutch disk looked like it was in good shape...

...but the transmission side of the clutch disk had NO friction material on it!!

The transmission-side of the disk's friction material had totally grenaded! Here's a pick that shows the pile of friction material I found in the bell housing, and it was big & thick chunks -- not dust. You can also get a sense of the level of destruction necessary to get to the clutch on this guy:

Whoever did the clutch last did a kind of sketchy job. They left a bunch of P.I.T.A. brackets that hold electrical loom and hoses disconnected. The bolts holding on the flywheel were mismatched (even though clutch kits come with new bolts), and the throwout bearing looked ancient.

I've never seen a clutch fail like this. Have any of you all? I have a few hypotheses:

• Maybe when I was driving home with an inop clutch pedal and dead battery, when I popped it into gear from a stop, the engine RPM changed so suddenly that it shattered the friction material on one side of the clutch disk?
• Maybe my S10 slave cylinder pushed the clutch too far and broke the friction material on one side?
• Maybe the last person who did the clutch cleaned off the flywheel with brake cleaner, but failed to clean off the pressure plate, so the clutch slipped really badly, only on one side, overheated, got brittle and shattered on one side
• Maybe the PO jammed it into 1st gear at interstate speed with the clutch in, causing the clutch disk to spin fast enough for the friction material to fail while the engine idled?
• Maybe the last person who did the clutch dropped or damaged the disk during install and cracked the friction material?
• Maybe the disk was just defective?

Who knows...all those seem pretty far-fetched...but whatever it was, it made me nervous b/c I bought the exact same brand of replacement clutch.

However, it went in fine. New oil seals. New bolts. New throwout bearing. New flywheel/disk/pp. I had to eyeball the alignment of the disk b/c the crank doesn't have a hole for the alignment tool to key into, but I must have gotten it pretty close because the transmission went on pretty easily. I got all the brackets installed properly this time. The CV boots, hoses, belt, water pump, thermostat, radiator, etc. went in with no big drama.

My aftermarket aluminum coolant expansion tank had leaky push fittings at the level indicator, so I threw the stock one back in. If I stick with the stock tank, that gives me an extra $100 in my budget to put toward rigging up something crazy like DIY nitrous oxide.

I've been driving it around for the last 3 or 4 days and it works great! The clutch feels great! It's a hoot to drive around in! I feel like it pushes my eyeballs in when I punch the throttle...but I'm sure a lot of that feeling is just because I'm used to driving my Vanagon.

Now I'm just driving it until the darned OBDII readiness monitors finally indicate "ready" so I can get it emissions tested and get a non-temporary Colorado license plate! And spraying accents in black Plastidip...mmm Plastidip! Gotta budget for more Plastidip!

Hopefully it won't give me major mechanical drama for a while, and my next few weeks of posts will be some boring aesthetic changes to make it look less horrible!

Great progress!!

The Mini passed Colorado's emissions!  (but I suspect it's at least partly because the Colorado state emissions testers didn't seem able to find the OBDII port.)

I've been driving it for over 200 miles. It runs great. I've done all kinds of drive cycles I've read about online. It's throwing no codes, but only 5 of 6 OBDII readiness monitors have gone to "Ready".  The "Comprehensive" monitor is still not in the ready state. I thought I'd take it in to get emission tested while I still have a half month left on my temp tags to see what happens.

The Mini is weird. The check engine light works but is labeled "SERVICE ENGINE SOON", and the OBDII port us way up under the dashboard behind a little, unlabled swing-down cover. I showed the folks at the emissions testing center the operational check engine light and also referred them to the owners manual. They looked under the Mini's dashboard long time, didn't seem to plug anything into the OBDII port, and put it on a dyno with a sniffer. The monitor by the dyno said "Fail". The result they gave me was an overall "PASS" showing super-clean emissions numbers but with a note that the check engine light was non-operational and a non-critical failure. Weird. Whatever. I'm happy it runs clean and I'll take the PASS.

I have seen that style of clutch disc failure. The specific scenario was a one week old Jag XKE with 800 miles. Poor little rich kid took it out of the dealership and started sliding his foot off the pedal with the revs up to launch. No warrantee was given, daddy paid us 22 hours plus parts, then bought sonny boy a 427 Cobra!

In reply to TurnerX19 :

Awesome story! Glad that type of failure could be chalked up to wanton abuse by the PO!

I found what was probably cocaine in the Mini.

SOOOO glad it wasn't discovered by a state trooper in Alabama on the way to the $2019 challenge! I can just picture it:  "That's not mine! I've never seen that before in my life!"

Thinking I'll not include the drugs in the budget as something that came with the car that I removed that I can claim as a FMV budget credit...but I might start referring to my little Mini as "El Chapo". 

My high school senior was driving with my wife as a passenger. I had vacuumed the carpets but not fully detailed the car yet. My wife reached into the passenger-side door pocket and found a postage-stamp-sized Ziplock baggie with white powder in it! Eeek!!!

I knew no one could prove beyond a reasonable doubt that the drugs were ever in anyone's possession other than mine. So, I flushed the drugs and called the local PD to see if they could bring a drug sniffing dog to see if there's more in the car. They sent a normal patrol officer who was super-nice and said they would have preferred that I gave them the drugs so they could incinerate them and not have them get into the water supply, but he also said such a small amount wouldn't really have any bad effects on the water supply and agreed that handing over the drugs wouldn't help them prosecute anyone. He suggested I just clean out the car really well and call them if I find any more.

So, last weekend, I pulled the seats; interior panels; and saggy, stained headliner. I recovered the headliner with some fabric from Joann, and I vacuumed the heck out of everything. I found candy wrappers, a razor blade, a ton of crumbs, 35¢ in change, and a Claritin, but no more cocaine. So that's good. The interior seems a lot happier with a new headliner, so that's good too.

Finding the cocaine really bummed me out though...what's the weirdest/sketchiest/most-depressing thing that you all have found in your project cars?

Congrats on the find, thanks for sharing the build, and hope to see you in Gainesville.