On the road again, finally!

March ’21 update: The car is actually running very nicely. It’s nice to see a plan come together, and this car has been full of good news. It’s also been a wonderful lift for my morale over this particularly long and gloomy year. Exhaust still needs welding, heat & A/C are both inoperative, gearbox still balks at reverse, loose front suspension, mysterious power drain, etc.. Ahhh, living “la vida classica”.

I’ve also registered the car as an antique…in a few short weeks this car will have a new plate & branded title. I’m still wondering how a car this modern can be eligible for antique status. I guess we’re both getting to be that way, eh?  Thirty-five years is a while, but it doesn’t feel like it’s been all that long. Time stops for nobody. Relatively speaking, three-and-a-half decades is a long time in the automotive world. When this car was brand-new, a ’50s BMW 501 would have been roughly the same vintage. Hard to believe, eh?

November 2020: Just tossed some different wheels on the car and took her out for a spin tonight. These are the ever-popular E39 540i 17″ Style 66 double-spokes. They’re scruffy, but they do fill the arches nicely. I might spend some time restoring them. I like the look, but 17×8″ wrapped with 225/50 tires are a ‘lil harsher than the 16×7″ Borbets I had on the car last month.

Still some problems, but the list keeps getting smaller:
The car still has some trouble with part-throttle and overrun. I can feel the AFM door slamming shut, it’s not smooth like I think it should be. Might need a little more tension on the spring wheel.
A/C also decided to stop working, and the heater fan is angrily screeching at all speeds.
The car has begun to baulk in reverse. Sometimes she’ll even moodily thunk the shifter back into neutral when I give her a little torque. I’m suspecting an internal transmission issue.

There’s a chance that it might be resolved with another fluid change and some finesse on the shifts.

A few details need buttoned up:
Wire up cruise control unit, oil sensor, CEL, track down a minor parasitic drain.
Repair an exhaust leak at the muffler.
Test the aftermarket OBD1 cat to see if it’s working. Doesn’t smell like it’s doing much good.
Engine is running nicely, rockers are still a little ticky-tacky.

In other news, the forward gears all work beautifully! Electrical systems are all go. The torsen diff is sweet, it’s easy to drive this car with the throttle.

May 2020: I just put some miles on the car tonight, and it felt pretty damn good too. First time driving it in nearly two years, since parking it in August ’18!

  • I can attest that the helical LSD works ever-so-nicely.
  • I was very worried about the gearbox since I’d found a good bit of water inside. I changed the lubricant and took it easy around the driveway. The shifter was a little stubborn in R/1/2, but the bearings weren’t making any bad noises. After a few miles all that remains is a balky reverse gear. With any luck the heat will gently dry out the gearbox and it’ll resolve itself back into shape within a few hundred miles. I’m getting to be more optimistic about my chances.
  • The engine is REALLY LOUD! I like the sound, but it’s a little obnoxious. Definitely needs a little a lot of welding. I’m also thinking that a stainless tubular header couldn’t hurt anything except the pocketbook. I’m keeping my eyes open for a nice used one.
  • Brakes are outstanding! That E34 540i upgrade gives good feel, firm pedal, nicely progressive. Highly recommended. There is a slight tradeoff in the brake pedal feel, it’s stiffer. Personally speaking, I’m OK with the firm pedal, it’s a little more modern. I do think that many other owners wouldn’t like the numb ‘wooden’ feel, especially if you’ve grown used to the stock brakes. The slightly larger E32 750iL master cylinder (22mm?) is a commonly matched accessory that would restore a more progressive ‘feel’ to the pedal.
  • The lightweight flywheel continues to amaze. Why I’ve never run one before is beyond me.
  • Wideband O2 is nice information to have on hand. The engine is running relatively efficiently, AFRs range around 13:1 most of the time.

Many problems also made themselves apparent; most are minor.

  • Did I mention that the engine is REALLY LOUD? To be frank, it’s obnoxious and totally out of character for a gentleman’s conveyance. Would I love this sound on a track? Sure! Would I like to hear it every time I drove through a residential neighborhood? Nope! Would my (admittedly very tolerant) wife be seen dead near this thing? Unlikely. That same constant droning is fun for a bit, but it gets old quick. It’s not really all that loud – I’d bet it’s still quieter than 99% of the asinine muffler-delete crowd. Yep, I’m looking at you, hardley rugged individual boutique shopper. You too, flatbrimmer vape dweeb. Don’t get me started on the bruh dozer mule or the muscle car weenies. Unlike those manchildren, I was taught to have actual respect for my neighbors, instead of flicking them the middle finger and saying ‘it’s mah right’. So fixing this is a high priority, but it’s beyond my current skill set. We’re looking at a good bit of welding, but that’s just part of the fun of well-used “free” parts.
  • Low-speed miss. I’m suspecting my hacked-up plug wires, but I also found a bad spark plug and the valves were overly tight.
  • Mild overheating. The thermostat housing worked up to 230degF within ten minutes…and it shouldn’t really get much above 190degF. I removed my old-fashioned red clutch-driven fan and swapped in a [far newer] black spare…appeared to fix the issue. On that first drive with a project car, I’m always sure to have a lot of tools. I usually take a jump pack, a few spare tires, and a tire inflator too. I’ve recently started bringing along an IR thermometer, it likely saved me an engine this time. Later on, I swapped in a more recent clutch fan, things dramatically improved.
  • It also appears that I get no heat in the cabin. Let’s hope the heater valve is good, since they’re expensive and rare. With luck it’ll just need a good bleeding, or the heater lines are plugged.
  • Handling is also slightly off. The front end is a little loose, the back doesn’t feel ‘planted’ yet. I’m suspecting the steering joints, the rear sway bars need new links. I’m planning on some upgraded E32 trailing arms, still looking for a decent set.
  • I recently found out that an E36 rear-view mirror will clip right onto an E23 mounting arm, and an E23 & E24 share the same arm. I was annoyed that my original E24 mirror was foaming up (why? what the heck do they put in there, Great Stuff?). I was temporarily out of good 80s spares (lots of 80s BMW used the same mirror, mounted onto different arms). The E36 mirror is ever-so-slightly wider, provides an improved rear view, and it won’t foul the sunshades. It wasn’t a perfect fit – a protruding ring prevents sufficient motion of the pivot, so I sculpted it with a die grinder until it worked smoothly and popped it back into the car. So it’s easy to fit an E36 mirror onto an E23 arm and have it work in an E24. I’ll continue to explore this topic, maybe an electro-chromatic unit is in my future?
  • Many more problems wait to be found, no doubt.

Planned upgrades:

  • Refresh coolant with BMW blue, Pentosin NF/G11 or Zerex G48 (G05 in a pinch). I prefer to run a 66% distilled water mix, with a bit of surfactant (RedLine WaterWetter or equivalent). The cast iron block and low-pressure cooling systems of classic BMWs are not as needy as the newer high-pressure mostly-aluminum systems they’re building now. I also fit the stock M30B35 pulley, which is a smaller diameter than the original B34 part. It spins faster (bad), pumps more coolant (really good), draws a bit more power (bad). Compromises are a part of life…but it’s a factory performance overdrive part!
  • Collector car insurance? (Done 5/11/20). I registered with Hagerty via Nationwide. It’s pretty cheap, all things considered. It’s like $150 for a year, including an overpriced flatbed towing option for disabled cars.
  • Figure out registering the E24 as a “classic” while complying with stay-at-home orders. (Done 3/17/21)
  • Replace the in-tank pump with the newer style single-pump upgrade.
  • Check & rebuild the suspension. Camber plates? Adjustable rear subframe with bearings?
  • Spacers in front & studs all ’round for the updated 17″ wheels.
  • Upgrade to Motronic 3.1 (M50NV), like this guy. Maybe use this cam sensor plate?