My Father passed away back in October, so now I own his 1987 M6.....

[OBwan]

I have assumed his account to keep track of his old post history for the various cars etc. I may change the profile name, but I haven't decided yet. Grab a beer, or a whiskey and put your reading glasses on (I know you’re mostly a bunch of old-timers like Dad and need glasses haha)… This is the start of a build/reno thread

Car:
1987 E24 M6, 145K miles, Black, White-ish leather interior with a LIKE NEW backseat, 5sp manual, 12/86 Build date (just like me, kind of serendipitous), stock except for some damn 1990’s Wolf of Wall-Street car cell phone antenna with RJ11 plug and an ancient car alarm system…more on that later

History:
Dad fell in love with the E24 and 80's body style BMWs when he was stationed in Germany back in the 80's and 90's. He eventually was able to buy a white L6 automatic sometime in the very late 90's but was never happy with it being an automatic, and not being an M. He found a Black 1987 M6 at auction and quickly sold the L6 and bought his M6 in 2000. I remember riding with him in the car once, maybe twice before he parked the M6 in the garage back in 2002, not too long after he bought it. He had received 2 speeding tickets in ONE WEEK with it and, being the miserly man he was, decided the insurance/temptation was too much. I was in High School at this time, so there was no way in hell he was going to let me drive his beloved M6 either. As we're all well aware with life, one thing led to another, and the car hasn't been driven since (that I know of). He retired from 30yrs active duty in the Army as a CW5 and Master Army Aviator and began trying to "get it back on the road" somewhere around 2015. I think he had swapped out the front control arms and sway bars, the front coolant reservoir, and a small list of other items, but I can't seem to find that damn list anymore.

Plan:
-I'm going to treat the car as a Barn Find since it "ran when parked" but that was 20 years ago.
-I’ll borescope the gas tank for how bad the rust is this weekend, I can't imagine it is anything short of terrible. The gauge is showing empty right now, so maybe Dad started down that road already…
-Replace the fuel pump and fuel filter regardless (unless it is obvious he just did that)
-Flush the fuel lines with fresh ethanol free 93
-Replace the spark plugs and check the coil packs (this thing has coil packs or something equivalent I assume…right?)
-New air filter and cabin air filter, check the MAF (again, I assume there is a MAF…right?)
-He had mentioned the week before he passed away that the A/C compressor was bad and he either HAD or was GOING TO get a special replacement from a forum member out of FL (I think). I think the Freon needs to be updated or modernized it sounded like
-The tires are showing definite signs of Dry-Rot but are holding air and will need to be replaced before I drive it any further than the gas station. I don’t think they’re the original tires, but they’re OLD.
-Then, I guess I’ll just go from there…….

Currently:
-When I pulled it out of my parents place 2 weeks ago, I was elated that when I hooked it up to the jumper cables on the truck, the seats worked, lights came on, dash lit up, but I couldn’t get any of the windows to work. Three of them were down, with a massive line of thunder storms between my parents place, and my place. I chalked it up to a bad switch, or relay….or something. No time to wrench, needed to get on the road and make the trek back home as the wife and kid were getting hangry. We got it winched up onto a car trailer with a friend’s Jeep, got a car cover from AutoZone that fit surprisingly well, and hit the road. 2 days later (only a 90 min drive, I was just lazy) we got it pushed off the trailer and into my driveway, but not into the garage. There was some mold in the car from sitting for so long and I didn’t want to seed that mold into my own garage.

-I did some research and found that a mixture of warm water, vinegar and a dash of borax works wonders to kill and remove mold from porous surfaces. I’ve spent the last week doing just that, combined with an Ozone machine intermittingly. Once I knocked back the mold to a level I was comfortable sitting in the car at, I began cleaning the seats and putting some moisture back into them with Lexol. They needed it pretty bad. The driver’s seat should probably be reupholstered, the passenger seat it pretty decent, and the back seat, to quote the wife, “looks pretty damn comfortable and new.” The headliner and rear pillars had most of the surface mold, but other than that, it’s in great shape. I did find a small mouse house and dead field mouse in the glove box with some droppings in the floor board, but the ozone machine took care of any smells surprisingly well.

-Today, I spent some time researching the window issue, looking for anyone with similar issues. It brought me right back here to a post from 2011 with an excellent answer by “master6” https://www.bimmerforums.com/forum/s...ws-not-working
I never in my life would have thought there was a damn circuit breaker in the dash that locked out the windows. So I got a new battery from AutoZone over my lunch break (fits great, is an exact fit Group Size 93 and Made in Germany, $199) and tossed it in the car after work. Hopped in, and turned the key over, fighting every childish instinct in me to try and start it (I won thankfully, I didn’t try and turn it over). All the lights came on again, the antenna went up, the A/C or heat started spooling up and blowing, it just came ALIVE. I reset the crusty feeling circuit breaker and started mashing on window controls to see if that was really all it was. The driver’s side goes right up, SWEET! Now for the rear windows as the passenger side was always up. They don’t budge. So I mash on the rear controls to see if I have a dead switch. Nothing. Then I find what looks like probably the child window lock button, fiddle with that, then try again. The left rear decides to go up now! Two down one to go. I try every combination of button presses and old TV Antenna alignment tricks to no avail on that last window. Then I try the passenger window to see if it will go down, it does, then goes back up when I ask it to. For the hell of it I try the right rear one more time. It goes up! Now I can wash 20years of dirt and dust off this poor car.

-There’s a rumor that it has a bad computer and won’t run/start, but I can’t confirm that. My uncle said my dad told him he had driven it up to the mailbox and back “recently”, but I can’t confirm that either. The driver’s side kick panel is out and there’s some wires dangling, it looks like he was messing with something as there were some tools and bolts laying around. I just found today what looked like maybe an old car alarm (it turned out to be exactly that) velcro’d to something else and a kill switch or remote control maybe? “Code-Alarm Model TRX-717SD” I’m hoping the computer is fine and the alarm system has failed and is locking out the starter/computer or something to that effect. Maybe the dash is apart because Dad figured that out, bypassed it and got it started and drove it to the mailbox? It is quite the quandary……

-I confirmed I have the dreaded TRX rims and tires, so I’ll be looking for some “new” BBS or similar modern rims in a 17” with modern rubber. As I understand it, the M brakes are good enough and to just leave them alone (no upgrades needed)

SO, what have I overlooked, where should I start looking, and what should I look out for? I started wrenching on older Audis when I was 20, so I’m familiar and comfortable with the German engineering mindset, just need to learn this new platform. I know my way around a car forum and how to use the search feature, I just don’t know what I don’t know.

So now I sit here about to post this, reminiscing about Dad, thinking about how I’m going to finally get this car on the road, make him proud, and daily driver an M6 for work. (2 mile roundtrip, 3x a week…I love my commute haha)

PS: Apparently I can only share 5 pictures per post, I have plenty more from the last couple weeks. I can share if there's interest.

[Lapis 635 Euro]

Sorry to hear about your dad and honorable to bring this M6 back to life! I'd recommend picking up the E28 Bentley Manual (lot of transferable knowledge even though you have an M engine as the cars share platforms). As a heads up, if you have power window problems again - the car has plugs in the front doors and rear panels that remove so you can crank the windows manually with a tool in the toolkit. The front seats look like they'd respond well to a full Leatherique treatment and can probably be saved. Keep us posted on your progress.

[Quasi635]

Really sorry to hear about your dad. Not all of us are "old timers" on the board, haha. I was born a year before you

The E24 isn't too difficult to work on under the hood. Electrical problems can suck on any car, hopefully the windows are just bad relays/fuses like you guessed. Definitely pick up an E28 Bentley manual if you want to learn more about the car. PM me if you would like a PDF.

You'll need to get tires soon so start looking for a nice set of 17" wheels. Lots of different OEM styles work on this car so you should have a decent amount of options available (check auto dismantlers, craigslist, facebook marketplace). I bought a set of 17" Style 5's from an early 2000s E39 with decent tires for $500 many years back.

Sounds like you have quite the project ahead of you. Good luck getting it back on the road! There are a couple of E24 Facebook groups as well that you should consider joining to find parts/advice. The people on this forum are MUCH more friendlier and helpful than those groups.

[Shipper]

Sorry to hear about your dad. Looks like a great project. And you have two speeding tickets in one week to beat! Keeps us all posted as you bring her back!!

[OBwan]

UPDATE: Pulled the fuel pump and sending unit and took a look at the fuel tank. It was 100% replaced or refinished because the inside is PRISTINE. The in-Tank pump is the original, as it has a date stamp of 11/86. OEM replacement looks to be $450+. Haven't found the In-Line unit yet but I'll get the car up on some jackstands and start looking. In the mean time I will probably drain out the older gas while I decide what I want to do about the fuel pump.

[1986series6]

You can get a pump like this, GSS 341 or GSS342-- I forgot which one lines up better.
Don't forget to order filter and harness adapter.

https://walbrofuelpumps.com/universa...uel-pumps.html

and fab it like this to save a bunch

https://www.youtube.com/watch?v=6uogNILRt40

[OBwan]

You can get a pump like this, GSS 341 or GSS342-- I forgot which one lines up better.
Don't forget to order filter and harness adapter.

https://walbrofuelpumps.com/universa...uel-pumps.html

and fab it like this to save a bunch

https://www.youtube.com/watch?v=6uogNILRt40

Perfect, thanks. I was starting to look into the Single Pump conversion, this helps a ton.

[1986series6]

This is not a single pump conversion. It's to replace a failed primer pump even though
the new pumps output pressure is higher than the original in-tank pump.

[OBwan]

This is not a single pump conversion. It's to replace a failed primer pump even though
the new pumps output pressure is higher than the original in-tank pump.

If the stock dual pump setup is only putting out about 145 LPH @43psi, why would the single in tank high pressure pump ~220LPH @43psi not be a suitable replacement/conversion? You do not want to dead-head the walbro 255lph pump against the OEM 145LPH (High-Pressure In-line pump)

https://www.bimmerforums.com/forum/s...3880-Fuel-Pump
https://treperformance.com/i-593443-...1976-1989.html
https://www.bimmerforums.com/forum/s...ow-hard-starts (TLDR: Hard Starts were due to a faulty pump connection in the tank, thus not maintaining line pressure)

[RSheiman]

Sorry about your dad as well. He bought an M6 so he knew cars.

Don't think an Audi and BMW are similar in any way. I had an Audi, it was possessed by demons. BMW's are much more user friendly.

The grease in the tracks for all these windows turns into a thick slop that basically slows the windows to a crawl or they do not move at all. I suggest you pull all the door cards and clean and re-grease each track.

I have said before, my 635 is like a child that asks for a dollar, my M6 is like a child that goes into my wallet and takes a twenty without asking! They share some parts, others no. Just look at the difference in price between diff mounts and then ask why a chunk of rubber should cost so much.

[1986series6]

I guess if the in-tank Walbro pump is @ 60psi, it could work as a single pump system.
I've read about single systems but can't recall if was an external pump or an in-tank
pump doing all the work.

[Bert Poliakoff]

My 81 Euro, build date of 5/81. is just a single pump mounted under the car. I am using a Pierburg pump that I picked up new on eBay for $50 or so.

[Sansouci]

It's proper that you are restoring your dad's dream car as tomorrow is Father's Day. It's a tangible way to keep him in your thoughts. I wonder if the Florida contact was the late Dean Cains in Lutz. As was said, this is a friendly and helpful community. Glad you joined.


Sent from my SM-G955U using Tapatalk

[Sansouci]

One resource you should have as you are into the dashboard is the ETM. You may be able to find it on the web from a guy whose website is wedophones. Take a look.

Sent from my SM-G955U using Tapatalk

[DesktopDave]

I'm loving this thread, glad to have you on the board! These are lovely cars, although the learning curve can be a little steep. Many mechanical parts are still reasonably common, except for trim and S38 motor parts.

Your car appears to be fully loaded, as you'd expect for an M6. You seem to have the full leather option, looks like the "lotus white" leather, with an upholstered dash & maybe headliner? Those are quite rare; BMW commonly replaced the leather covered dash & upper door trims due to delamination issues. Most M6 I've seen ended up with the standard plastic dash & upper door trim and a partial leather interior.

I don't think you'll find coil packs. Later versions of the M5 did, but you should have a distributor with a single Bosch coil on the passenger inner fender.No cabin filter nor MAF. These cars run a similar device called an AFM. It's a fancy door connected to a variable resistor that measures the air volume instead. I do believe your S38 might have a chambered intake manifold with a rudimentary variable-length setup.
-He had mentioned the week before he passed away that the A/C compressor was bad and he either HAD or was GOING TO get a special replacement from a forum member out of FL (I think). I think the Freon needs to be updated or modernized it sounded like
I think the A/C unit is the same on all the M30 cars, they're pretty cheap. An r134 conversion typically causes mixed results, largely due to the small condenser. Just to make things more fun, BMW installed many different compressors. Hopefully it's a Bosch 'wingcell' those are relatively simple & durable. One of the members here even rebuilds them.


I see you've discovered your M6 has the once-desirable TRX wheel option. They are quite easily replaced with the quite similar E38 16" Style 5 wheels, a bolt-on option. You even got the sweet forged BBS cross-spokes. Definitely don't let those get away from you...they're worth quite a bit (just like the remainder of the car).

[OBwan]

Mini Update: I have the new walbro pump in the tank and the sending unit back together. I was able to drain most of the fuel out of the tank, and will flush the little that's left with some fresh gas. Next step is to delete the inline pump, flush and pressurize the lines to the FPR, change/check the spark plugs, then put some coolant in and see what happens.... hopefully this week. I went with the walbro GSS340 and did have to trim about .5" off the stock brass hard line to shorten the overall length.

Thanks everyone for the kind words and the many various tips. I really appreciate it. I found a hard copy of the 1987 L6/M6 ETM in his things, and my mom found the replacement ECU he had apparently already ordered in their closet, so I was pretty stoked about that. I'm hoping its just a faulty alarm system locking the starter out or something, and not the ECU. Time will tell

[DesktopDave]

Take some time to jump the main & fuel pump relay sockets to see if your crank position senders are bad before condemning the DME (ECU). These early Bosch DME have a crude safety system that will open the FP relay if the speed sensor signal isn't detected. These two relays are pretty reliable in general, but occasionally prone to internal failure. I make a new jumper set for every old Bimmer I get, leave it in the toolkit along with some known good main & FP relays.

As for the crank position sensors...your car should have two sensors on the bellhousing, they are identical in terms of specs, but quite independent in terms of function. The speed sensor counts flywheel teeth, the position sensor detects a single 'pin' on the flywheel. There are several failure modes:
The flywheel pin is noted for falling off at times, be sure that it's present & accounted for. Oddly, it's not machined into the flywheel, it's a little steel block that's retained by a very small roll pin.
The speed & ref sensors are accidentally swapped at the intake manifold bracket, or the rather delicate connectors are wasted, or the sensor heads are clogged up with ferrous magnetic debris. They are similar to ABS sensors AFAIK.
The sensors' resistance is out of spec (should be approx 1Kohm between pins 1&2).
The sensors' floating ground is damaged or shorted (look for open circuit or quite high resistance between pins 1&3 and 2&3).

[OBwan]

UPDATE:

Once the fuel tank and pumps were taken care of I finished flushing the fuel system and tried to turn the car over. To my amazement, it fired right up after 3-4 cranks. After taking care of some small things like coolant levels and "check lights" I was able to take it for a quick drive around the block. The power steering however was non-functional. I've now discovered that the PS Fluid reservoir is essentially empty. No idea why, but I guess that is the next rabbit hole. I'll try just simply filling it up and see what happens, then start digging deeper and doing a rebuild on the pump I guess. There a loud RPM dependent whine which I am assuming is the PS Pump screaming because there is "no" fluid in there.

Edit1:The hoses appear to be new with new aftermarket hose clamps, so I am working off the assumption that Dad just hadn't put fluid back in yet.
Edit2: Put some Dexron III compatible ATF fluid in and went for another drive, PS is perfectly fine and the whine is completely gone. Brakes still feel like they're dragging though

[MIKYZZ4]

A flush and bleed of the brake fluid in the brake system would be something I would do.
Considering that you classify this as a "barn find", I would have drained and replaced ALL fluids, but that's just me!

[Venom13132]

Sorry for your loss.

I have been wishing I had an E24 lately. I think they are such cool cars. I really hope you can make this car the best it can be. Excited to see you bring it back to life Such an awesome car.

[DesktopDave]

Sweet! Glad your DME is alright.

I'd check for a hung up parking brake shoe inside the rear rotor hats. FYI, the front brakes are special to the M6. You'll have quad piston fixed calipers and M6-only rotors instead of the single-piston sliders the 635CSi came with instead.

It's possible that the dragging brakes were due to low hydraulic fluid. I know that sounds odd...but the E24 got a hydroboost brake system too. Our hydraulic P/S system also boosts the hydraulic brake servo, and they share the same reservoir of ATF.

It's easy to overfill the reservoir, fluid levels can vary quite a bit. It's best to check the level after purging fluid from the "bomb". The system uses a black spherical hydraulic accumulator that looks like an old cartoon bomb, it's underneath the brake booster regulator on the driver's inner wheel well. MyE28 has a lot of info here. The bombs can fail and lose internal pressure on occasion. That can result in complete brake failure...I'm told that it can feel like overheating or fading brakes during the early stages.

[vonhummel]

Thrilling to bring one back to life.
After sitting for a few years, my M6's front caliper pistons would not release after the first drive. I was able to rebuild them and the have bee fine since.

[OBwan]

Now that the PS is sorted, I've moved onto the front brakes. The front right caliper is definitely dragging, and as it heats up, it begins to "seize". I looked into OEM replacement, which I've determined is simply just not possible, short of finding a junker and pulling potentially worse calipers off. I then looked into BBKs but didn't want to drop $3K on a BBK that would require me to go with 17" rims and new tires since I just got the 16" Style 5s painted and mounted with new Bridgestone Potenza's in 245/45-16, which is difficult size to find rubber for. Luckily I found a shop nearby that specializes in car restoration and specifically brake restorations too. (https://whitepost.com/brake-sleeving...ding-services/) About $350 per caliper depending on how many pistons need to be sleeved. Seems like my best and only option short of trying to rebuild them myself. The rears seem to be fine, the parking brake works and they don't seem to be dragging. I'll do a power flush with new DOT 4 fluid after I install the rebuilt calipers.

Now onto the next Mystery, the instrument cluster. The speedo, temp gauge, fuel gauge, and backlighting doesn't work. The tach and damn service light work though. This seems to have already been identified as there was another cluster from another M6 (I assume) with 115K miles on it, and also a completely new circuit board as well sitting in the trunk. Anyone have any guesses on that?

[DesktopDave]

Overhaul is an excellent idea for your brakes. Those M6 fixed calipers are near-impossible to find used, regardless of condition. They are a very popular upgrade for many other BMWs, and were never that common to begin with. If you were looking for a superior & cheaper upgrade, I'd suggest E34 540i brakes. The rotors, calipers & carriers are a direct fit, front & rear. They're a good fit with your 16" style 5. The E32 740i is nearly identical, save for the rear rotors. I'm running that setup on mine (blog post), it's slightly heavier but quite an upgrade for an E24.

As for the gauges, it's likely minor corrosion or grounding issues inside the cluster. I've also found loose harness plugs not connected properly to the cluster. The two grounding nuts are also infamous for loosening up. They're on the rear of the cluster from the backplane/control board to the gauges (here's a great YouTube guide for the similar E30 setup). The SI board can also have damage from leaking batteries, and I've also occasionally found burned traces on these 80s circuit boards.
Hopefully your backlighting problem is just the bulbs being burned out. That circuit runs through the headlight switch, the integrated dimmer rheostat does occasionally fail. I've seen bulbs that fell out of their holders, dangling behind the cluster.

[e24mpwr]

Now that the PS is sorted, I've moved onto the front brakes. The front right caliper is definitely dragging, and as it heats up, it begins to "seize". I looked into OEM replacement, which I've determined is simply just not possible, short of finding a junker and pulling potentially worse calipers off. I then looked into BBKs but didn't want to drop $3K on a BBK that would require me to go with 17" rims and new tires since I just got the 16" Style 5s painted and mounted with new Bridgestone Potenza's in 245/45-16, which is difficult size to find rubber for. Luckily I found a shop nearby that specializes in car restoration and specifically brake restorations too. (https://whitepost.com/brake-sleeving...ding-services/) About $350 per caliper depending on how many pistons need to be sleeved. Seems like my best and only option short of trying to rebuild them myself. The rears seem to be fine, the parking brake works and they don't seem to be dragging. I'll do a power flush with new DOT 4 fluid after I install the rebuilt calipers.

Now onto the next Mystery, the instrument cluster. The speedo, temp gauge, fuel gauge, and backlighting doesn't work. The tach and damn service light work though. This seems to have already been identified as there was another cluster from another M6 (I assume) with 115K miles on it, and also a completely new circuit board as well sitting in the trunk. Anyone have any guesses on that?

Rebuild kits aren't expensive for the M6/M635 brakes. Might want to try that before deeper solutions. I had a dragging RF caliper recently also, and a $20-ish rebuild kit solved the issue (the shop did it, but it's not hard to do). I bought an extra for the other side - if you need a PN I can dig around and find it.