Owning, driving, and working on the same car for a long time is like being in a long term relationship. You’ve become so intimately acquainted with another being that you can tell right away when something’s wrong. You know which noises are normal and which ones mean trouble’s afoot. The sights, sounds, and scents are familiar and any deviation from normalcy instantly triggers those internal warning bells and sirens. “Sure, it rattled, but it always does that over bumps when making an off-camber left turn in cold weather in second gear with the heated seats on.” “She said ‘It’s fine’ but her intonation indicated she meant, ‘That’s okay’ and not, ‘F you.’”
A new car - or more menacingly - a project car cobbled together in a few weeks in one stall of a three car garage like my V8-swapped M3, is more like a new baby than a long-term relationship. Is it supposed to wobble and flex like that? Why is it so noisy? Did it just backfire? Does 5W20 have all of the necessary amino acids?
And so it goes with a fresh engine swap. It’s all a mess of trying to figure out what’s normal and what’s not, shaking down any problems built into the system, and getting familiar enough with the car to recognize when something is wrong. Here is everything that has gone wrong on my V8-swapped M3 so far.
Useful as a Rock
First to fail, obviously, was the part made by GM. I bought a set of LS truck coils on eBay and slapped them on my engine.
After I had completed the obligatory three-times-around-the-block shakedown run, I decided it was probably safe to drive the car the five miles to work. On the way there, something felt a bit...off. Given that this is my first V8, my first rear-wheel-drive vehicle, my first BMW, and that one could easily find fault in my implementation of the steering, clutch, accelerator, shifter, and every other component of the swap, it’s hard to immediately know what’s normal. But it didn’t have the punch I remembered, and the exhaust sound was definitely strange.
I got it home at lunch time and, on a hunch, used the Megasquirt software’s test function to drive each coil manually. Number 2 was flat dead. So I ran over to Autozone and grabbed a replacement Duralast coil in stock for all of $36. Sweet.
Charged with Failure
After a few hundred miles I noticed my battery light flicker on acceleration, indicating the alternator may be on its way out. This alternator was pulled from a junkyard Explorer and cost $25, so I wasn’t exactly astonished to find out it was garbage. I pulled it out of the car and lugged it into Autozone where they claimed they could load-test it for me (I chose that location because they had replacements in stock). Their alternator testing machine has an interface that lets the operator punch in the make/model/engine, then provides detailed step-by-step instructions for mounting the alternator for testing, down to the exact adapters and cables needed. It’s a brilliant system designed to be idiot-proof, taking all uncertainty out of the equation. But as the universe often does, it built a better idiot, and I spent 45 minutes standing there watching them fumble with the machine, unable to secure my alternator. Finally after three Autozone employees put their collective brilliance together they were able to test it and surprise surprise, it was dead.
So I ponied up the $150 for a remanufactured replacement alternator wtih a lifetime warranty, dragged it home, and voilà, functional charging system.
Until two days later.
My wife was out of town for the weekend and I wanted to hit up a Cars and Coffee at a local performance shop. I was up until after midnight on Friday night getting a new steering rack installed and laser-aligning the car.
The next morning a friend met me at my place, I loaded the two year old in the back seat, and we headed out toward C&C. Except after about a block that pesky battery light reared its ugly face again. We turned around and grabbed the tools required for an alternator swap, then headed back to Autozone which was kind of on the way to C&C anyway.
When we arrived I asked if they could do an on-car charging system test (hoping to avoid a repeat performance of the Great Alternator Test Debacle of 2015), but they found that my battery charge was too low to support a charging system test. It was low because it powered my drive to AutoZone without any help from the alternator.
Great. So we just yanked the alternator off the car right there in the parking lot. On the Explorer setup it sits on top of the engine on the passenger side and comes out with three bolts and a wrench on the belt tensioner. Luckily Autozone’s Saturday Morning Crew was much more proficient than the Wednesday Lunchtime Gaggle and they confirmed a dead alternator in just a few minutes. The brand new (non-remanufactured) DURALAST GOLD BEYOTCH alternator was an extra $40 over what I paid for the $150 reman unit, but because I did the work of pulling the alternator in the parking lot, the dude knocked $15 off the price for me. Score.
The clutch setup on my car is a hodgepodge of parts from BMW, Ford, Summit, and Datsun (yes, that Datsun). After a few hundred miles, I noticed clutch effort increasing. On occasion, it would grind going into reverse. After a while it became difficult to get into first at stoplights. I figured there must be an issue with the 125,000 mile BMW master cylinder or the $9 (yes, nine whole dollars) Datsun slave cylinder. Repeated bleeding helped nothing.
One day, while doing a brake job on the wife’s car, I had to run across town to the O’Reilly’s that had the right brake pads in stock, so I threw the two year old in the back of the M3 and headed out. It was about 10 miles, half of it in-town driving, half of it interstate. Things were going fine until I exited the interstate where it became very clear that something was wrong. Much more wrong than it used to be. With the clutch pedal jammed all of the way to the floor, the car didn’t want to idle in first gear, it shuddered and shook like my wet dog spiting me for his not-quite-consensual baths by permanently staining the bathroom walls with a vigorous shake. So I pulled it out of gear and it idled fine. Once the offramp light turned green, it took just about as much force as I could muster to smash it into first gear. I repeated this process at a couple of stoplights until I finally got to O’Reilly’s. I grabbed the brake pads that I needed and asked if they had a jack available for me to borrow so I could bleed the clutch. They said they didn’t (something about avoiding customer crushing incidents in the parking lot), so I knew I was in for a fun ride home.
By now it was about 4:30 and rush hour was ramping up, all of it in the direction I needed to go to get home. It took a couple of tries to even get the car started, as it hated sitting still in gear. I manged to back out of my spot and get it into neutral, but after that it Would. Not. Go. Into. First. I shut the car off, and immediately it slipped right into first. Oh great, now it’s obvious what I’m going to have to do. I released the brake, put the clutch pedal to the floor, and turned the key. As the starter spun the engine, the partially engaged clutch drove the car forward until the engine fired after a couple of seconds. Good thing I ponied up for the high-torque starter from Summit.
I considered my options and picked out the most direct route to take home, planning carefully to avoid any stop-and-go traffic. My brilliant route home had me taking an immediate left turn, crossing two lanes of rush hour traffic that didn’t have to stop and merging into two more lanes of rush hour traffic that also didn’t have to stop. Well, looks like I’m going right. So much for my brilliant route. For the entire drive home, I had to look as far ahead as possible, gauging how long until that next red light was going to change, and trying to coast so that I wouldn’t ever have to come to a complete stop. Which still happened at least 7 times. I’d stop at the stoplight and kill then engine, then put it into first. When the light turned green and traffic started moving, I cranked the engine and the car scooted forward as it fired up. Once moving, the importance of rev-matching while shifting was made abundantly clear to me - my 1-2 and 2-3 shifts caused enough bumping and grinding to make even R. Kelly jealous.
I finally made it home, lifted up the car, and yanked the transmission out, only to have the throwout bearing fall out of the bellhousing in several pieces.
So clearly the throwout bearing on my cheap eBay clutch kit cracked, causing the higher clutch effort and reduced disengagement until it finally bent so far and/or broke that it wouldn’t disengage the clutch at all. Luckily there was no damage to the pressure plate.
So I grabbed a new name-brand throwout bearing (that alone cost me about 20% of what I originally spent on the entire eBay clutch/flywheel/TOB kit) and threw everything back together.
Oh wow, suddenly clutch pedal effort is barely more than my Focus. Engagement is predictable and smooth. It’s...
Fault: Cheap eBay clutch kit
Okay HOLY COW we’re pushing like 1567 words so far I swear the stupid car has only broken down like two other times.
Steering Toward Disaster
I’ll try and make this one quick in a lame and unsuccessful effort to pretend that your time matters to me.
My very first autocross. I didn’t know anyone there, but I was determined to prove that I AM SENNA and my car WILL DESTROY ALL. At the end of the very first run, I hear a ghastly whine corresponding with my engine RPM. Either some delightful soul sneaked into my engine bay and installed a supercharger, or my power steering pump was begging for mercy. I parked it and saw a trail of fluid from the finish line all the way to me.
The end of the metal power steering fluid cooler is crimped to the rubber return hose that goes back to the reservoir. The hose tore at the crimp, meaning it could not just be clamped back together. Surprisingly, a whole bunch of Gorilla tape didn’t do the job of sealing a large volume of quickly flowing power steering fluid.
Actually, nevermind on valuing your time, this is actually kind of a fun story. After finally coming to the realization that there was no way I was going to make it home without ruining the power steering pump while spewing ATF all over the road behind me, a dude with a trailer offered to drag me home at the end of the day. Cool. I texted my wife and let her know that I ran into trouble but had it figured out.
Come 3:30pm, everyone’s packing up to leave and I pull the car up to the trailer to catch my magic carpet ride home. Except that the bottom lip of the trailer is about 5 inches off of the ground, and the dude’s Neon race car scrapes every bumper and side skirt getting on and off. I’d have no chance. So I phoned the wife to let her know I’d need a ride home. No answer. Texted. Called. Texted. Called. No answer. Oh yeah, it’s naptime. So I blasted Facebook.
A friend that didn’t live too far away stopped by to pick me up and gave me a ride home. By that time it was about 4:30 and me getting home woke up the wife (what a life, right?). I immediately called U-Haul to see if I could get a trailer, but they were closing in 30 minutes and had none available until the next morning. No problem, except for the problem where the tow-capable car is what my wife usually drives to work, and she’d rather not take #TeamHatchback for the day - she can handle a stick just fine (snortle), but would prefer not to be reminded of her lack of natural coordination during morning commuter traffic. So first thing that next morning, we both hopped in her car and made it to Starbucks so that we could wait in line for fifteen minutes in order for the race car fund to buy her a mocha.
After that we hit up U-Haul and hooked up a tow dolly, then headed straight into morning traffic with an unloaded tow dolly bouncing wildly into any lane it wanted to get downtown where the M3 was (hopefully still) waiting. Luckily it didn’t get towed overnight, so I backed the Edge up and got the car loaded. This led to my favorite succession of Instagram posts thus far.
Now the hitch I installed on the Edge is technically rated at 3500lb capacity. The M3 is somewhere in the neighborhood of 3250lb, and the U-Haul dolly is 750lb. I maaaay have told U-Haul’s online form that I was going to be pulling a ‘93 Festiva so it would sign off on the rental.
All things considered, the Edge performed admirably for being sliiiightly overloaded and had no problem cruising at 65mph on the interstate. I made it home and was able to drive the M3 into the garage, leaving a telltale trail of fluid pouring from its beating heart from the street right into the car’s temporary resting place in the garage.
I ordered a replacement power steering cooler and got the thing all fixed up within a couple of days.
Most of my formative high school years were spent terrorizing the streets of small Iowa towns in a 118hp Ford Probe. A friend from that era came to visit so of course we needed to go for a ride in the M3 and laugh about how we could have possibly had any fun back then with so little horsepower. We hopped in and headed out around the block. We edged out of the neighborhood and onto a four lane road, where I promptly put the pedal to the floor and broke the rear end loose through all of first gear. Friend laughed maniacally. Slam the clutch pedal, crush the gear lever into second, pop the clutch while mashing the gas pedal again and...nothing. Accelerator went to the floor. Car crept along at idle. I coasted into a nearby CVS and grabbed my bin of tools from the trunk (because of course by now I’ve learned to carry a bin of tools). After pulling the driver’s footwell panel, I found this.
See that brass cable end and the shredded wires jutting out of it? That used to be the throttle cable. Now, I’ll be a man here and take full responsibility for this one. The brass bit is supposed to be a cable end for, say, a motorcycle clutch cable. It’s definitely not supposed to splice two cables together, but a BMW M3 isn’t supposed to have a Ford V8 under its hood. What can I say, I defy convention (and logic, and sound reasoning, and best practices for cable splicing...).
Fortunately for me, the 5.0 has enough torque at idle that I was able to drive home entirely at idle. I even got into second gear at one point.
This was the kick in the butt that I needed to finally redo the whole throttle cable setup to eliminate the throttle sticking closed and insane off-idle sensitivity I’d been suffering through for the past who-knows-how-many-hundred miles.
A real cable splice:
And a hacked-up throttle cam/cable from a junkyard Expedition. A little bandsaw here, a dab of welding there, a spring from Menards to top it off, and voilà, a throttle.
Remember that “A Whole New World” picture from 1080 words ago? It’s that all over again. The throttle cam allows more gradual throttle application off idle, making the car far less jumpy, jerky, and more stable. It’s now far less likely that the wife spills her coffee all over these pristine leather seats. Not that that’s ever happened before.
Out of all of those problems, only one was actually my fault, and only once was I legit stranded. Oddly enough, the one issue that stranded me was entirely BMW’s doing and could just have easily happened with the stock engine in place. I’ll take that as evidence of my brilliance, no matter what those around me with good judgement continuously say.
And just as new parents eventually figure out how to interpret their baby’s cries, I’m finally getting enough seat time with this car to establish what I hope is a beautiful long term relationship. As long as I avoid off-camber left turns in cold weather in second gear with the heated seats on.
Catch my build thread here with a new installment some Mondays, or if you like spoilers check out MikaelVroom.com for the latest updates. Twitter me@MikaelVroom, Instagram me @MikaelVroom, where you’ll see that I’ve long since moved on to other projects, completely forgetting about this one.