bought a second z3

adrian_Z3

Regular Member
Joined
Feb 20, 2025
Points
14
Model of Z
1996 Z3 M44 5MT | 1999 Z3 M52 Auto
Hi Z3 gang,

The main purpose of this post is because I need to make at least 5 posts in order to list some stuff in the for-sale section 😉

Anyway


A while ago I bought a ’96 M44 roadster, 5MT. It was a pretty rough example, but I made do and carried on with the “restoration.” I put a ton of money into rebuilding the front suspension, added a Bilstein B12 Pro suspension kit, new slotted and drilled rotors and pads, and a bunch of random things like sourcing interior trim pieces to rebuild the degrading interior.

I replaced the oil filter housing gasket, spark plugs, and redid the entire cooling system. Funny enough, I was never able to get the heat to blow hot. I even replaced the wiring for the climate control knobs, heater control valve, flushed out the heater core several times, and made sure the vent flap door was functioning—still no heat. Ah well. It did blow cold though, which was nice in summer.

When I bought the car, the entire rear trim was missing—but that ended up working out because I installed a Hard Dog roll bar, and with all that trim already gone it made the job way easier.

I also replaced the passenger side window/top rubber seals (those little rubber pieces love to pop off). Then I dropped the exhaust and driveshaft and rebuilt the shifter linkage, adding some Garagistic poly bushings. Man
 the shifter felt amazing after that. Unfortunately, that’s when I noticed my second-gear synchro wasn’t very happy. Aggressive downshifts into second wouldn’t even engage—I’d have to try a few times to get it in (hehe). So that was
 unfortunate.

I also added Condor Speed Shop poly engine mounts and transmission mounts. That definitely added a lot of NVH, but you know
 race car things. I even swapped the stock black center console for a wood-grain one.

I still had big plans for it:
  • source some sport seats
  • start building the M44 to its peak with cams, etc.
  • rebuild the rear trailing arms with new bushings
  • and eventually source an LSD
  • find a new getrag 250D and while im in there, clutch and a single mass flywheel

UNFORTUNATELY, one day while the roads were wet and my tires were bald, I went a little too hard around a corner and ended up becoming very acquainted with a tree on my passenger side. Lol.

The passenger door was cooked, the lower rocker was donezo, and the windshield cracked at the A-pillar. I was able to drive the poor 1.9 home, and luckily none of the driving aspects were affected—no leaks, still starts right up. However, once I removed the passenger door and lower rocker panel, the true damage became evident. The chassis was dented to hell, and the lower door hinge had been pushed inward so far that even after finding a color-matched replacement door from a junkyard, it would no longer align.

The A-pillar had shifted a few millimeters—just enough to crack the windshield and prevent the top dowel from lining up with its hole. That meant I could never properly close the soft top again.

I took it to a body shop for a quote: $2,500 just to pull the hinge and A-pillar. No painting, no extras, and no guarantee that things would align properly afterward. Not to mention that after replacing the windshield, there was a good chance the first pothole I hit would just crack it again since the A-pillar was no longer in its factory position.

At that point I decided I’d be better off putting that $2,500 toward finding another chassis—maybe another 1.9 in the same color (Arctic Silver is pretty common). My thinking was that if I found one with a bad engine, I could just swap all my good parts over and be back where I was.

After a few weeks of checking Copart and Facebook Marketplace, I found a potential option:
A 1999 2.5L inline-6 Z3 roadster with 60k miles, black paint, black interior, and black sport seats (SCORE!!). It also had 18” M-badged wheels (I suspect they’re reps
 but that’s fine with me). The interior was very intact too—rear compartment, hoops, all that good stuff.

I was able to secure the deal for $2,300.

The bad part: it had clearly been sitting for a long time (I suspect something like 16 years
 wow), though the seller couldn’t confirm. I had to bring my own battery, and once I hooked it up the car started coming to life electronically. I didn’t try cranking it though—the oil was bone dry, so it had clearly leaked out over the years.

The tires were completely dry-rotted, so I had to tow it out. The rear window in the soft top was also totally gone, so I had to buy a car cover as a temporary solution since I don’t have covered storage right now.

Oh—and it’s automatic (darn).

My current plan is to get the 2.5 back to life and restore it to a “daily-able” state. After that, I’ll start swapping over the relatively new suspension parts from the 1.9. Then I’ll start working on a manual conversion with a ZF. Meanwhile, I’ll be parting out the 1.9. The engine runs perfectly fine (133k miles), so hopefully I can sell that and recover some costs. Once I get my money’s worth from parting it out, I’ll scrap the rest.

I figure if I’m patient enough, I’m thinking I might actually recoup most—if not all—of the cost of acquiring the 2.5
 and maybe even, dare I say, profit slightly.

Plus, there are a lot of good parts from the 1.9 that will be swapped over to the 2.5. Honestly, it’s pretty nice already having a donor car sitting around for the project!

-AJ
 

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I like the wheels. You do have your work cut out for you but it will pay off in the end.
 
Oooph ! Naughty Tree !

Gosh, doing some work there, kudos to you . . .

thanks for the kudos, in retrospect, the tree allowed me to receive some humility :whistle:

I like the wheels. You do have your work cut out for you but it will pay off in the end.

yep this will occupy my free time over the spring/summer for sure. On the wheels, any idea if they are genuine bmw wheels? I haven't been able to ID them hence my suspicion that they are reps. Either way they do look cool.
 
Update:
Alright so I finally got around to trying to start the 2.5 m52tu after doing all the basic revival stuff. Fresh oil and filter, new battery, new intake boots and air filter, cleaned the MAF and ICV, dumped some oil and Marvel Mystery Oil into the cylinders and let it sit for a couple days, new spark plugs, coolant flushed and refilled. i took the fan off and turned the engine by hand to make sure it wasnt seized- it turned very easily and felt right. So at that point i was ready to give it a try. I put some fuel cleaner in the tank and then some 93 octane.

I pulled the fuel pump fuses and cranked it a few times to build some oil pressure. Put the fuses back in then tried again, nothing. Hit it with some starter fluid and it fired right up and sounded good, but only ran for a couple seconds before dying. Did that a few times and same result every time.

It also blew a ton of white smoke out of the exhaust, which I’m not too worried about since I soaked the cylinders beforehand. Figuring that’s just everything burning off.

So at that point I started looking into fuel. I don’t hear the fuel pump priming at all when I turn the key, which already had me suspicious. But then I noticed something else. With the key in position 2, the dash does its normal thing for the most part. Oil light, brake, low fuel, ABS, seatbelt, all that comes on and then some of it goes away like it should. But there is no check engine light at all. Not even for a second.

From what I understand that’s not normal, and it’s kind of pointing me away from just a bad fuel pump.

Where I’m at now is thinking the DME isn’t powering up. That would explain no fuel pump, no fuel delivery, and why it only runs on starter fluid. I checked the fuses visually and tried swapping the relay in the DME box, but it didn’t change anything.

So currently I’ve got a car that cranks strong, will fire on starter fluid and sounds fine for those few seconds, but won’t run on its own and has no CEL in position 2.

Next step is to make sure I’m actually hitting the correct DME relay, try swapping with a known identical one, and check for actual power at the DME-related fuses instead of just eyeballing them.

Feels like I’m close, just need to track down why the DME isn’t waking up.

any tips?
Thanks
 
Dont get ahead of yourself here fuel pumps are a common failure.
So is removing the engine check lights bulb on dash to hide a fault.

First thing get a code rwader and a 16 to 20 pin bmw obd adapter do a cide read see what if any there if reads that thats a good start that ecu has comms

Behind the drivers seat you will see a circle half cut out you need to complete the door then behind that you will find the fuel pump / sender until check for power
Pulse on ignition stage 2
Continuous on crank.
Stephen.
 
Update:


Got INPA hooked up with a K+DCAN cable and pulled codes from the MS42.


First read showed 10 faults stored. Most of them were stale and cleared out without coming back. Old brake light switch plausibility code from way back, a couple EVAP leak codes which are expected after sitting this long, and a cluster of throttle position and voltage regulator faults that all occurred at the same time and appear to be from a past event, maybe when the battery originally died years ago. There was also an IAC opening coil short to ground code but that didn't return after clearing either. No EWS faults stored at any point.


The two codes that keep coming back are 131 and 132, both CAN bus communication errors between the DME and the instrument cluster. INSTR2 and INSTR3 messages timing out. Static faults, currently present every time I read.


Here's the interesting part. Battery voltage at the terminals reads 12.46V with a multimeter, but INPA is showing the DME only receiving 10.51V. That's almost a 2V drop somewhere between the battery and the DME. I'm pretty sure that low voltage is why the CAN bus communication is failing, which means the cluster and DME can't talk, which means the EWS handshake through the cluster never completes, which means no fuel injection. That lines up perfectly with the car starting on starter fluid but dying immediately since spark works fine without the CAN/EWS loop.


I cleaned up the engine to chassis ground straps but that didn't change anything. DME voltage stayed low and the same two codes came right back.


Next step is doing a voltage drop test at the DME harness connector to figure out if the loss is on the positive feed side or the ground side. Once I find where those 2 volts are disappearing I think this thing will fire right up.
 
Update: it's alive and driving
Following up on the no-start. Short version: it was the fuel pump.

I'd been chasing DME/power issues because my thinking was that if the DME wasn't getting full voltage it might not be triggering the pump. @Stevo7682 called it though — fuel pumps are a common failure, and that's exactly what it was. The pump looked practically new, but it was dead. Swapped in a new one and the car fired right up and stayed running. So the starter-fluid-then-die behavior was just no fuel delivery the whole time.

Couple other things I did along the way:
  • Did an EWS delete on the MS42
  • Put in the correct instrument cluster (the car had come with the wrong cluster installed by the previous owner- a non can cluster from earlier model years. i think it was 99' and after that got the new CAN02/03 type clusters... 131/132 CAN faults are gone). It was plug and play- tach, temp, fuel gauge and speedo all work. But i had to salvage a few bulbs from the donor car's cluster.

I've got about 100 miles on it now. Drives fine, automatic shifts fine.

One thing I'm trying to figure out: after driving a bit, when I come to a stop and let it idle, I get large puffs of smoke out the exhaust. I also see some smoke coming off the valve cover toward the back, around cylinders 5 and 6 — figuring that's a valve cover gasket due for replacement. For the exhaust smoke at idle I was suspecting the CCV/PCV, but with the engine idling I can pull the oil cap and feel a slight vacuum, which tells me the PCV is doing its job and there's no vacuum leak on the intake side at least. So I'm not sure what the smoke is about. Open to ideas.

Everything else that got done:
  • Pulled the wheels it came with — turned out to be real Style 67 E46 M3 wheels. Going to restore and sell those. Picked up a set of stock 16" "starfish" wheels with decent tires off Marketplace for $200.
  • Brake fluid flush and refill.
  • Took the sport seats out and fixed the classic bushing rock — solid now. Driver seat wiring was corroded to hell with some severed wires, so I cut the connectors off the donor car and spliced them in. Also replaced the driver side motor so the seat position switch works again.
  • Pulled the center console and door cards and found the previous owner's stereo "work." Re-spliced in the factory 17-pin connector (had one from the donor car) and the factory door speaker connectors. After that my aftermarket CarPlay head unit plugged right in with the adapter harness — all speakers working first try.
  • Swapped the steering wheel from the donor car — better condition and it has the airbag. The original was missing its badge and the airbag was gone.
  • Refreshed the center console with a new trim panel and took the best buttons/switches from both cars.
  • Door cards refreshed with new clips (3D printed the clip mounts), and the handles are solid enough to actually use without ripping them off now.

Next up: suspension, install the Hard Dog roll bar, swap the rotors and pads over from the donor (it's got slotted/drilled rotors and newer ceramic pads), and start collecting parts for the manual swap. Anyone got a ZF S5D-320Z transmission? :)
 
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