Rebuilding My 1988 US-spec M5

[vinceg101]

(Apologies for photo-bombing/cluttering your awesome build thread)

[Ricky535]

That's inspiring. Very clean. I'll have to dig out my B35 vibration dampener and pulse generator bracket.

[jhh925]

Way past time for an update.

Bottom line up front: She runs! Click that link for a very short YT video with poor sound. The bad sound is in part due to my lack of technical skills but also due to all the air that the PS pump is trying to compress. And if you said, "I thought the power steering pump is supposed to pump, you know, power steering fluid," you'd be right. Anyhow, that problem is now fixed: I pulled the PS pump belt and used a hand drill laced through the dangling belt to spin the pump till it was primed.

After getting the motor running, I turned to body, interior and other more cosmetic stuff.

First, the parcel shelf. I got a spare from the 528e I parted out a couple years ago so that I could keep the original one untouched. With my daughter's help, we stripped off the old covering, sanded it a bit, sealed it with poly, then glued new carpet on it. The carpet is 'saffron' from World Upholstery. I actually matches the unfaded carpet in the car pretty well. We also added a layer of felt to the back, though had I managed to remember that the old, large felt "blanket" actually starts on the parcel shelf we would have skipped that step. As it is, I now have two layers of felt under the parcel shelf.

Spraying the poly on the new pressboard:



Gluing the new carpet & felt on:



Result:



And sitting in the car with the old blanket in place. Don't you love the cool patchwork pattern I've made trying to fill in the holes left by all those no-doubt "professional" audio system installers?!?





I also fabbed a mounting plate for the ECU. The '179 ECU has the 55-pin connector in the opposite orientation from the 35-pin connector on the original ECU. Looking at the last pic below, the original ECU connector sits at the 9-o'clock position; the '179 has to have the connector at the 6-o'clock position.

I used a cardboard test pattern to cut this piece out of aluminum plate:



It mounts to the body above the glove box using the mounting holes from the original ECU:



And now the '179 sits like this:



Front & rear glass is in, sealed up with 3M Bedding & Glazing compound, and all the trim pieces & lock strips are in place. Unlike last time, I put the Bedding & Glazing compound in before doing the trim & lock strip. That made it a whole lot easier to run the bead under the rubber, but it also made things a lot messier as I was putting the trim & lock strip. No pics of the mess ... sorry! The upside of the mess (e.g., all the black goo squidging out) is that I know that the rubber is definitely sealed all the way around.





Next, in preparation for putting the front seats back in, I had bought new front seat belt receptacles ... about two years ago ... off of eBay ... where sellers think that E30 = E28. Hell, they're both old BMWs, right? Well, the E30 receptacle won't fit the E28 power sport seats because the "chicane" on the mounting end of the E28 part has an extra 15mm of offset.

Problem:



Solution:



Unbelievably, the local HW store had a 15mm tall spacer with a 14mm ID that fit perfectly over the mounting shoulder on the seat. So using a set of shoulder bolts, these spacers perfectly hold the E30 receptacles with the right stand off.

Happiness is four new OEM "fuzzy" door seals. The seals are cut correctly for the rear door openings, but have to be trimmed for the slightly smaller front doors. I made this jig to hold the seals in place so I could get a nice clean edge with a chop saw:



Result:



Next I turned to the euro front side lights. I modified the two-filament, three-wire US bulb holders to fit into the euro side lights:





Though, as you may know, the US bulb holder when combined with the plug that comes on the wiring harness gets pretty long and runs into the bodywork behind the valance. The easiest solution I could come up with was to de-pin the harness-side plug and put the spade-connectors directly into the side light. I used a zip-tie to hold the rubber boot on. This arrangement ended up fitting pretty well.



Here's the current state of the build. I think I'm really digging that yellow pinstripe stripe all the way around the front grill. Very period-correct.



And interior:





Next steps:

- Put hood back on
- Put Euro M5 front spoiler-chin on
- Re-bleed the brakes & clutch
- Figure out what to do about the ABS sensors; the old wire coating is completely disintegrated and new sensors seem to be about $200 per corner
- Complete the wiring connections in the dash in preparation for the first drive. Plan here is to mount the minimum that will allow me to safely drive around the block but still allow me to trouble shoot issues later without having to keep taking the driver side knee bolster & glove box off. I'm hoping not to put those on till the car really seems to be running right.
- Line up some kind of help to tune the Motronic 1.3 set up. I think I have a dyne guy in Seattle that's very familiar with these M30B35 & S38 motors. Fingers crossed. And fingers crossed we can do a good tune remotely. Trailering my car all the way to Seattle isn't realistic.

Slowly gettin' there ...

[milarsky]

PM

[sanships]

Jhh925, nice build, where were you able to get the “fuzzy door seal”? Would like to get a complete set for my car.

Thanks

[jhh925]

Jhh925, nice build, where were you able to get the “fuzzy door seal”? Would like to get a complete set for my car.

Thanks

I was able to get a full set ... but that was 2-3 years ago. (Yes, I started buying parts early.) And IIRC, I had to go to at least three places to buy a full set of four seals?

If you don't have luck, you might try this solution: https://www.mye28.com/viewtopic.php?p=1487074#p1487074. It's not the factory original, and you'll need to be handy enough to cut a clean 45 degree miter for the corners, but I believe this aftermarket solution was created specifically for this generation of BMWs.

[Collin380]

@jhh925

Great concept, work, and progress...Bravo!

I have the same stalled project with my M5, and have been inspired by your thread.

Looking forward to seeing the final result...

[jhh925]

This build is getting down to just the oh-so-very short strokes. Though, still on the "to do" list is one biggie: Getting the ECU chip tuned correctly for this motor.

First, the update:

I cut the oil cooler holes out of the OEM euro M5 chin and sprayed on a coat of SEM (a stain black intended for plastic, IIRC?) to cover the newly cut portions. The original pressed plastic part is actually a gray material that comes painted from the factory. So when you cut the oil cooler holes, you expose the gray. I spent some time to make sure the holes were cleaned up and I'm pretty pleased with the result.





I also modified the "low beam" connections for the H4 bulb & holder so that the high beam filament in the H4 bulb will light up when I put my high beams on. (In a euro car, the high beam filament in the H4 bulb never gets lit.) I did this by buying a spare back-plate and cannibalizing it for the missing connections, then digging out the sealer on my backplates, and using a hot Xacto knife blade to melt new slots where the cannibalized connections fit in. (This isn't my process; this was described in a couple of threads here in the forum.) After slotting in the new connectors, I put epoxy in to replace the removed sealer.





I've put new vapor barriers on all the doors. I bought about four meters of the stuff that W&N is currently offering, and I'm very happy with this material. Very strong, very sticky, easy to cut, mostly easy to pull off if you need to reposition (as long as you haven't really pressed it on hard yet). My method was to (i) put masking tape on the edge of the door so that the inside edge of the masking tape outlined where the final edge of the trimming foil should be; (ii) cut a section off the roll that is about the right length (30" in the rear, 32" for the fronts), (iii) pull a bit of the backing off and stick the foil onto the door just along the top edge; (iv) hold the foil against the door and cut the foil (with the backing still on there) along the inside edge of the masking tape (the yellow-on-black provided a very visible guide through the foil backing), and then (v) finally pull the backing off and pressing the foil into position. On most of the doors, I detached the inside door handles first then cut the foil in place.





So now you might say, "Hmm. Fabric in the door cards. Interesting. Not what the M5 had originally, is it?" Nope, it ain't. I gave this quite a bit of thought. First, the smooth leather door card inserts are one of my least favorite parts of these interiors. It's expensive material for sure, but it looks plain and gives me a "cold" impression of that surface. So what to do instead? I could have done perforated leather (one of the big suppliers offers a really nice perforated leather that would have perfectly matched the new 'natur' leather), but that would have looked just like the basic E28 interior, so that was a no-go. I could have done Alcantara, but I did that on the last car. I tried hard to find a nice wool houndstooth check pattern cloth as a way of doing a bit of a tip 'o the hat to the old BMW check pattern interiors, but I had no luck finding a material I liked. So with my daughter's help, we picked out a nice upholstery at a local place that we felt matched my interior. The cards are easy to modify, so this can be changed later if my mood changes (and more on that later).

I now have the entire interior in. A few notable items ... the two-part center section around the parking brake has always puzzled me. I glued the top to the bottom section and we upholstered it as one. It's stiffer and cleaner this way, though I assume that adjusting the parking brake will be very slightly more complicated in the future. And it looks nice next to the new (and very red!) seat belt receptacles.





A note on those receptacles. The solution I described above (use E30 parts, add spacers to accommodate the E28 sport seats) did not end up working. As it turns out, receptacles with the correct "offset" for E28 sport seats are readily available, but the PN is technically for the E24 seat. Puzzling. (Try 72111945991 if you want it with the seatbelt warning pigtail, or 72111945992 if you don't care about that. Or one for each side with I think is maybe what BMW had in mind?)

One bummer (for now at least), I wasn't able to get my replacement center "AC blower vent" section properly covered in natur leather. (The US M5 has the area around the ashtray covered in matching leather.) Although I like the black-on-tan look of that part, it's not correct. I have a plan on how to fix that (again, more on that later).

I ordered the wrong-wrong-wrong floor mats from Lloyds. That color doesn't match *at all* and the pattern I later discovered was for an M6, not an M5 (my mistake). I'll be offering a new set of Lloyds mats for an E24 shortly. Groan. I then did what I should have done in the first place - I ordered swatches from Lloyds. Here there are. Number 2 is the closest match in the pics, but in real life #1 is better, so that's what I ordered. And this time I double & triple checked that I was actually ordering mats for an E28 pattern.





OK, on the interior (as hinted above), here's what I'm thinking: If you look closely in the pics above, the seam stitching has a pretty long "pitch." That is, each individual stitch is maybe 3-4mm long, but the original seams were much tighter and shorter (maybe 1-1.5mm?). The parts I have in the car will have to do for now. I want to turn to engine tuning & get this car on the road! But longer-term, my thought is to source another set of interior parts to replace the ones that are currently covered in leather and that have or are supposed to have any seams (dash, door caps, armrests, center sections, glove box, knee bolster) and have them redone in the same leather by a new shop that can do the much closer "baseball stitching" seams and can also shave the leather so that it's thinner and can be worked onto these surfaces in a way that's closer to the original. I love my current guy, but he doesn't have the leather shaver tools or a sewing machine that can do the dense stitches.

Speaking of engine tuning, here's what's currently going on. The motor has been fully converted to Motronic 1.3. The only chip I have is for an M30-B35. With that chip, the car runs, drives & idles (in fact, here's a short driving video! The 'check engine light' was because the AFM wasn't connected, and the ABS light is because I have at least one bad sensor. The AFM issue is corrected; new ABS sensors are in-bound.), but I've found at least one odd issue. After the car is warmed up, the exhaust temps where the headers connect to the head are extremely hot. On my 535, I never saw temps over about 580-600 deg F. But on this car, the surface temps on the headers are getting up to 820 deg F. The best explanation I've heard is that the current timing is very retarded so that the air-fuel mixture is still in the process of burning as the exhaust valve opens and the pistons start the exhaust stroke. I have a company in Seattle (22nd RPD) that is going to try to do the chip tuning remotely, but I do have some concern that these super-high temps may warp the head before the timing is corrected. I've checked surface temps elsewhere on the motor and everything else looks normal. And the engine coolant temp gauge sits happily at about "noon," so this doesn't seem to be an oil or coolant issue.

Here are a couple of current pics as I start to work through my punch list.

[Ordnator]

I believe that the E21 316 (single headlight variety) item 11 Covering Cap (63.12.1.358.819) will perform this function out of the box.

The E21 single headlamp had the low beam & high beam function within the single lens. I have read somewhere that this is what you need to turn your Euro E28 low beam into a low & high beam setup. There is also some wiring upgrade and control circuitry to manage the additional current draw with 4 x high beams and low beams combined.

https://www.realoem.com/bmw/enUS/showpa ... Id=63_0023

On my list of potential upgrades for the Eta's.

I had my Diamantschwartz Eta re-trimmed back in 2016 by these guys:

https://www.dclass.co.uk/

A long way to send your parts but this is the end result for my Eta:

https://www.dclass.co.uk/gallery_images/bmw-525e/

Dave is a real artisan and I recommend his work without hesitation.

My daily beater E28 looked quite out of place with all the exotic cars at his shop but Dave took on my work as his personal task. He loves working on "coil sprung horse hair filled proper seats not the modern foam filled rubbish"

He mentioned shaving the back of the leather to assure that when folded the piping would match the original size. He also shaves the leather when fitting over dashboards, kick panels, hand brake consoles, glove boxes etc.

He scoured Germany for the older style thicker thread again to match the original but in the new colour for the re-trim.

Top drawer work and a top bloke to boot.

Best regards,

Mick

[Tiit]

Thanks for sharing. Curious to see how M1.3 tuning will work out.

[jhh925]

I believe that the E21 316 (single headlight variety) item 11 Covering Cap (63.12.1.358.819) will perform this function out of the box.

The E21 single headlamp had the low beam & high beam function within the single lens. I have read somewhere that this is what you need to turn your Euro E28 low beam into a low & high beam setup. There is also some wiring upgrade and control circuitry to manage the additional current draw with 4 x high beams and low beams combined.

https://www.realoem.com/bmw/enUS/showpa ... Id=63_0023

On my list of potential upgrades for the Eta's.

Good to know! I'm hoping not to have to upgrade wiring. In my case, I'm leaving the US system in pace (looking at just one side, I'll have one filament burning in the H4 for low beams, and one filament in the H4 and one in the H1 for high beams. I believe that should be the same wattage in each lens as the original US system (tho I have to admit I'm doing those numbers from memory) so it should be the same current draw. I'm not hoping to light both filaments in the H1 when I hit the high beams.

I had my Diamantschwartz Eta re-trimmed back in 2016 by these guys:

https://www.dclass.co.uk/

A long way to send your parts but this is the end result for my Eta:

https://www.dclass.co.uk/gallery_images/bmw-525e/

Dave is a real artisan and I recommend his work without hesitation.

My daily beater E28 looked quite out of place with all the exotic cars at his shop but Dave took on my work as his personal task. He loves working on "coil sprung horse hair filled proper seats not the modern foam filled rubbish"

He mentioned shaving the back of the leather to assure that when folded the piping would match the original size. He also shaves the leather when fitting over dashboards, kick panels, hand brake consoles, glove boxes etc.

He scoured Germany for the older style thicker thread again to match the original but in the new colour for the re-trim.

Top drawer work and a top bloke to boot.

Best regards,

Mick

That's some nice work for sure. And yeah, that would be a hell of a ways to send all those parts. Who knows. In a few months I may be desperate: I just got a messafge back from the Bay Area shop I was hoping to have do the work and among other things they said, "We really only do pre-war cars." WTH, it's all just leather, isn't it??

[Bret]

Very inspiring build. Discovered your 535i build from the BaT listing, and naturally ended up here. Can't wait to see more.

[jhh925]

Very inspiring build. Discovered your 535i build from the BaT listing, and naturally ended up here. Can't wait to see more.

Thanks. Unfortunately ... life. Project has been stalled. My sister and I finally convinced my parents to move into a retirement / assisted living place. The final straw involved a call my mom received from the "IRS" about an "unpaid tax bill" that my mother urgently had to pay. By cash. I'm OK laughing now because we managed to get the $9,500 back from UPS. Now, you might ask, "ninety-five hundred? Why didn't they ask for a nice round number, like ten grand?" Well, they did - and I'm sure that the "IRS" doesn't need to worry about factoring laws anyhow, but when we got the package back from UPS, there was only $9,500 in there. Apparently - and I'm dumfounded all over again as I write this - my mom enlists my dad's help to package up the money. Does he say, "Hey, honey, maybe this isn't such a good idea, maybe we should rethink this." NO! He palms $500 for himself - and then forgets where he stashed the money. So while my mom is getting ripped off by the over-seas branch of the IRS, my dad is ripping off my mom.

So, needless to say, that changed the priorities list a bit.

On the car, what I really need to be doing is focusing on getting the motor running right. It starts great and idles great when cold, but has odd behavior after it warms up. More on that in a later post when I'm able to turn to engine tuning tasks in earnest.

In the mean-time, as time allowed, I focused a bit more on some clean-up items - principally getting the trunk liner back in shape and installed.

Over the months (or maybe years at this point?), I've been collecting odd bits of M5 trunk kits with the goal in mind that eventually I'd end up with at least one full set of good parts. I think I mostly accomplished my mission except for the rear bullhead cover. In that case, I found a great regular E28 trim piece (no carpet, just plain gray cardboard). And although I had a full set of pretty good parts, in most cases the cardboard backer had been significantly damaged by water / humidity / use / etc. I got anthracite unbacked carpet from World Upholstery, which is really nice stuff, but it looks very obviously "new" when compared to the original 30-year-old carpet bits.

So, my strategy was:

- Gently separate any cardboard backing material from the carpet
- Steam clean the carpet
- Repair the contoured cardboard pieces (rear trim piece and the long piece that covers the taillights and rear tail panel)
- Replace the flat cardboard pieces with thin MDF that's been sealed & painted to match
- glue it all back together and put new carpet on the rear bulkhead trim piece

Here are some before pics:






And here are some in-process pics. The MDF was sealed using a gray paint that was pretty close to what I think the original cardboard color was. I also added a piano hinge to the first aid cubby door so that the old carpet wouldn't have to support the door anymore.







And here's what I did for the contoured cardboard. First, I got the cardboard a bit damp and lightly "sanded" the worst of the moldy mung off. Then I did sort of a "papier-mâché" layer using wood glue and onion skin paper. I cut sections of paper out (4x8 mostly - 8x8 was about as big as I could do without getting bubbles under the paper), thinned the glue out with water, brushed the mix onto the cardboard, got the paper lightly wet, then smoothed the paper into the glue on the cardboard, let it dry overnight, and trim the edges as needed. That let me actually re-create some of the missing cardboard at the corners, repair any rips & tears, and stiffen the piece up overall. I also gave them one coat of poly after drying so that they'd be more sealed from moisture in the future. Here are a couple of pics of the tail piece:




I also covered the edge of the cardboard tail piece where it goes around the trunk latch. It's always bugged me how BMW made a part that was supposed to make the trunk look classy, finished and expensive - then they leave a plain cardboard edge showing on the trim piece. C'mon. (Also, I managed to get rid of the residual glue you see in the pic with a bit of adhesive remover. Final product is a bit cleaner than you see here.)




And here are some pics of the pieces installed:





One issue I discovered is that the new MDF backing is a bit thicker than the original cardboard (about 2.5mm vs 2.0mm), so the cover for the emergency triangle (when the triangle sits in its cubby on top of the battery) won't sit securely on top of the battery box. That will be a fix for another day. I'll probably have to cut more MDF and thin it in a thickness planer. We'll see.

Oh, I also had a spare few minutes, so I figured I'd polish & reinstall the front strut brace. But this happened:



The engine vibrates against the bar when it's running. Not sure why it fit when I got the car but doesn't fit now. I've taken it off for now.

I also finally installed the windshield washer jets and accompanying washer fluid lines. Jets, tubing, clips and check valve are all new.



And you can't quire see it in that pic, but I fabbed a replacement hood ground strap. The E32 hood lifts are a great upgrade, but the original ground strap is too short to allow the hood to open all the way if you try to mount the ground strap in the original position. So I used some black wire (6ga IIRC - maybe 8ga - can't remember) and a couple of heavy gauge terminals from West Marine to make a pretty-close replacement. Here's a shitty screen shot zoomed in on the above pic. I'm told that these ground straps originally came with clear plastic insulation from the factory. Anyone know where to get clear insulated 6ga or 8go battery wire?



Anyhow, that's all for now. Gotta take this call about my car's extended warranty ...

[Fanclutchnut]

Re: strut bar, I’m betting you tried this, but does flipping the bar help with clearance? It might be parallax in the photo but it looks bowed down. Also a spacer/washer under the bar mounting flange might give needed clearance.

Loving the trunk work. Ours has water damage to the masonite/cardboard backing and your solutions look great.

[jhh925]

Re: strut bar, I’m betting you tried this, but does flipping the bar help with clearance? It might be parallax in the photo but it looks bowed down. Also a spacer/washer under the bar mounting flange might give needed clearance.

At the time, it was already late and I was out of time - the thought did occur to me then that "hey, maybe I should flip this over." This bar has an eccentric at one end that will only fit one way (IIRC), so at the time my thought was, "nope, can't flip it." But as I write this, it occurs to me that all I need to do is swap the mounting plates side-to-side. That should let me flip the bar the other way. Doh. Thanks for the mental prompt.

[EuroShark]

I have the same bar and it'll only clear my plenum with some thick washers between the strut tower and mounting plates.

[leadphut]

One of my favorite threads. Terrific job! More please

[SeattleGuy]

Gosh. Congratulations to you for your wondrous efforts on this Beast.

[tig]

<3

[e24mpwr]

This thread makes me:

A) Tingle
B) Realize I need to spend more time at MyE28

[jhh925]

Thanks for all the kind words! Move to Reno is pretty much complete ... and somehow after going from a two-car garage to a four-car garage, I still don't have enough room. Frick!



Yes, I know, the "M" is still to close to the "5." Other things that are still on the list:

• Get idle cleaned up. Likely need to readjust the butterflies.
• I'm not happy with the quality of the leather coverings on a bunch of the interior parts, especially the bunching on the dash. I'm collecting more parts to try to get a re-do on that stuff.
• I have the original basket weaves on the car. I have refinished BBS wheels that are ready to go on there as soon as the front end in properly aloigned ... but man, those original basket weaves look great. Need to reconsider the BBS wheels.
• I can't clear the "Rear Brake light" warning on the check panel. This one's a puzzle. Everything in the rear brake light check circuit is fine, and even shorting the pin on the check panel doesn't clear the light. I've tried to re-flow the solder on the board, but I haven't had a change to test my work yet.

And of course, the M5 project in the far stall (background in that pic) is taking most of my time.

[reesesboot]

Without knowing what BBS wheels you're thinking of putting on the car, I still vote for the originals. They really fit the understated vision of your build.

[jhh925]

Without knowing what BBS wheels you're thinking of putting on the car, I still vote for the originals. They really fit the understated vision of your build.

I just spent 30 min scrolling through years of pics on my phone ... I could have sworn at some point I took a pic. Regardless, they're refinished BBS Rs061 - so the correct size for the E28 M5. Refinished by FrankPoweder (lolz - I can't believe I managed to dodge that bullet). Here's a pic of BBS RS211 wheels on my old 535. The 061s for this car are finished essentially the same (maybe slightly darker centers).

My M5 has a slightly lower stance, so the blingyness might not be quite as, uh, bright.



Yeah, the originals are probably better.

[BDKawey]

the trunk refresh came out awesome. my tail light carpet piece is in rough shape, could definitely go for the same treatment.

[jhh925]

the trunk refresh came out awesome. my tail light carpet piece is in rough shape, could definitely go for the same treatment.

Not on Tetanus?!? Would a nice clean trunk go with that perfect name+aesthetic combo?