E34 M5 rescue

[Kowalski2011]

With the hectic holiday season in the rear view, I thought I would post up this account of my recently acquired E34 M5. I bought this car back in mid November and have driven it for exactly 36 miles and one car wash before garaging it for the winter. Now I really can't wait for spring!

I have to say from the onset that I am not a mechanic but a mid-level DIYer that enjoys the BMW platform, to be sure. This involves driving, detailing and routine maintenance along with keeping all systems functional, and occasionally enlisting the help of an indie shop when needed repairs are beyond my scope. I am not of unlimited resources and am now maintaining 4 BMWs, though the other 3 are basically sorted and modded to my liking, so this year’s budget will be mostly directed towards the M5.

I posted this initially on the M3 board because the day I bought the M5 I had to move the M3 out from winter storage in the garage stall where I have QJ and tools so I could work on the M5.

I repeat that post here.

So here’s the story-

The year was 2004. That summer I retired from the Navy, bought the house on the cul-de-sac in my hometown and bought my very first BMW, a 2004 330i ZHP. Later that same year the house next to mine sold. My new neighbor, Dr. C, was a family practice physician recently hired on at the clinic.

Some years went by and then one day there it was, a black 1991 E34 M5 parked in my neighbor’s driveway. Then it was gone. I later spoke with Dr. C and turns out the car is his and it’s been sitting in his garage since he moved in. After that I only rarely saw the M5 out in the driveway.

It was way back in April 2014 when I offered to purchase the 1991 M5 from my neighbor, Dr. C. He said that he seriously considered my offer, but decided not to sell. I think his wife was more motivated to sell the he was. I offered to assist him with whatever help or advice he may need getting the car out and driving. As we all know things come up and these cars can be needy, but very rewarding when cared for.

Later that year I sold the house and moved up to the lake.

As the years passed I ran into Dr. C. occasionally and we always spoke of the M5. No he hadn't been driving it. Work and call and family he said. I gave him my indie shop's contact info. He always seemed enthused about getting it back into shape and driving it.

Just this last summer when we ran into each other he told me he had the car hauled to the shop. He said they cleaned the gelled gas out of the tank, new lines and filter, couple of radiator hoses, belts, new battery and a new set of tires so the car would start and drive. He was getting the car ready to sell. I offered to help him detail it and list it on BaT if he wanted to try to sell it there. No he said he didn't care for the internet, preferred to talk to people.

I did some research to determine just what I would be getting myself into if I were to make an offer. I'm a fairly decent DIYer but now with 3 other BMWs my annual car budget would need a raise. She's gonna need some TLC!

I thought to myself, do I want to take this on? And do I want to add a 4th BMW to the garage? - I have more space now but to put the M5 in means my truck will be demoted to the driveway.

I called him up and made a first pass inspection. The battery was dead even though less than a year old, we used a jump starter. The car started and the engine sounded OK on cold start. There were no oil leaks on his garage floor.

I later mailed Dr. C. an offer based on Hagerty's valuation scale. A week later he called me and said that the mechanic at the shop offered him 'x' and his wife said 'sell'. He said he would rather see me get it for that, if I really wanted it. I bought the car the next day.

Here it is in his garage the day I came to pick it up. While I do not have any maintenance history on the car, I do know that it has been stored here just like this for the last 18 years. Ten of those years this was a mere 50 feet from my bedroom window!



The signed over title shows 79,233 in 2001. Dr. C never registered this car for the road as the plate that was on the car expired in June of 2001!



At the gas station about a mile away the day I bought the car shows 79,527. The car has only been driven 294 miles in 21 years! What a shame.



I drove it home in the snow.



Here's a motor shot.



Since I do not have a service history, I'll need to rely upon a thorough objective inspection in which the mysteries of her former life 1991-2001 can only be surmised. My intentions are to freshen her up and drive her as intended, but with respect. As a long time BMW fan and owner/driver, I feel truly blessed to have this rare opportunity to experience one of the last hand-built M5s.

And so the bond between man and machine begins.

[Chappers 71]

Very nice…enjoy.
I used to have a Lagoon Green 1991 3.6, you’re gonna love it

[SW111]

Cool story. I had one and I loved it!

[M-technik-3]

Love the Whitewall's System II's with fans look great, such an understated car. Buddy of mine just bought EU spec Daytona Violet one.

[IcewaterPete]

What a great story! That is going to provide you with a ton of enjoyment. Can’t wait to see the updates as you fully sort it out.

[grannyknot]

Congrats, not many of those left, 1991 so that could be the S38B36 3.6L engine, 311hp or possibly the S38B38, 3.8L 335hp.

I've owned an e24 M6 with an earlier version of the S38 and a e34 535 and I wish I had never sold the e34, one of the best highway cars I ever drove.
Both of those cars were known for some electrical gremlins so it would be worth spending some time cleaning all of the electrical body grounds down to bare metal.

The 6 independent throttle bodies are the same across all of the S38 engines and I can almost guaranty you the 15 needle bearings supporting the throttle shafts and linkage shaft are by now seized with hardened grease and dirt.

Your car is still fairly low mileage so hopefully the hard chrome covering the soft brass shafts won't have worn through yet but if it has you'll want to free up those bearings soon before the wear gets bad.
The only real way to do that is to remove them from the intake manifold and disassemble them.
I know that sounds like a daunting task but really it's pretty straight forward, here is a link to my DIY on the S54 ITBs but the procedure is pretty much identical.
https://www.zpost.com/forums/showthread.php?t=1962915

The first set I rebuilt were from the S38 in the M6 and at 176,000mi the shafts were badly worn and had started to allow vacuum leaks.

Looking forward to pics of your restore.

[Kowalski2011]

^^Thanks for the great advice and DIY! Definitely going in the file for future reference.

Check out this ad I found in Car and Driver from 1987:

M5 Hettel 100.pdf

Yep, that's what I got right there:



I also found remnants of an old HOFCO car alarm:



I checked and the black box has been removed.

" If you were around in the late 70's and 80's then you know these alarms and the patented Hofco passive kill switch saved many Porsche owners from having their cars pinched. It was very common to have stripped out 930's show up on fire in vacant lots around LA and OC, nothing left but the tub. They are inherently easy to steal but putting a small hurdle between the thief and a running engine worked most of the time. Sometimes insurance companies required anti-theft devices before they would provide coverage. The Hofco installation was very sanitary and could be removed without harming factory wiring, ask technicians from that era and they will verify this important detail. There were lots of hacks but Hofco was the only dealer installed alarm system in the LA area from the late 70's through the 80's."

Since the car has a title history starting in California I'm gonna bet she lived some of her early days in the greater LA area. Somebody surely didn't want his baby getting boosted!

[grannyknot]

The Hettle 100, does it still work? Very cool.

[Kowalski2011]

Yes still works! I have never heard of such a device before I saw this and googled it. I've thought about replacing the entire handbrake with a stock one but have yet to source the leather boot - no way the current one is coming off over that lock device. So I guess I'm keeping it.

[KevinC]

[Kowalski2011]

With the M5 laid up for the winter I'll do what I can in my garage.



Where to start? Replacing all fluids with new and known to be correct, and a good inspection underneath. The diff fluid that came out looked like shit - chocolate brown. New fluid and a test drive determined that the shaft input diff seal is leaking. I have some shop time scheduled for mid April for this and some other work.



New ATF in the transmission - the old also looked like shit.

New coolant flushed and filled with BMW blue. The old coolant was the green stuff (?) and didn't look bad, just green. Now I know and trust what is in there.

The oil was clean and golden, the sticker in the windshield listed 0w40. I replaced that with Redline 15w50. In the future I would not hesitate to use TWS same as in the S65.

I replaced the air filter and cleaned the MAF.

WTF here? I contemplated not even replacing this screen that is in line after the MAF. Why is this even here? There is also a screen in place before the MAF so this second one seems useless. And if metal wire bits ever got sucked into the intake it could be a disaster for the motor.

[grannyknot]

Originally Posted by Kowalski2011

WTF here? I contemplated not even replacing this screen that is in line after the MAF. Why is this even here? There is also a screen in place before the MAF so this second one seems useless. And if metal wire bits ever got sucked into the intake it could be a disaster for the motor.

I've heard a couple of explanations but an air straightener makes the most sense to me, that ripped one isn't doing much straightening though.

[Almuliman]

"Air straightener". Sounds like blinker fluid

Were I in your place—and boy, do I wish I were the one with an E34 M5—would not leave the ripped one in place for sure.

[grannyknot]

Originally Posted by Almuliman

"Air straightener". Sounds like blinker fluid

That's just term they use, from what I've read the screens are suppose to smooth out the air turbulence so there is a clean linear flow moving past the MAF sensor and then in to the throttle trumpets.
BMW says they are necessary although anyone with a Evolve or Afe modified intake is running their engine without the benefit of those screens, so

[Mani59]

Thanks for sharing this awesome story! Look forward to further updates.

[Llarry]

Two words: Throwing stars.

[positiveions]

Congrats.
Welcome to the BMW classic club. I would love to own one, but the angel (my wife) on my right shoulder keeps reminding me that I own too many cars (only 4).

[TriumphTim]

Looks awesome, in my opinion the best M5, just the right mix of size, engine, and excitement. Sure the newer ones are faster but are bigger and less raw.

[Kowalski2011]

Originally Posted by Llarry

Two words: Throwing stars.

Agreed! Those are my favorite wheel for this car and would be my first choice.
However a decent set is going to cost a pretty penny!

For now I'm going to clean up the style 20 turbines and run them. A little spit shine and new roundels. Dr. C. placed a new set of 'performance all-season' tires just before sale so these will be good to go.





Meanwhile, I'll focus my resources ($$) on drive-ability and reliability items.

I found the SLS rear shocks to be DOA. I'm not messing with these, they gotta go.



I chose to re-circulate the SLS at the firewall just below the driver. I'll also cap the the SLS system in the rear at the accumulators.







Here are the replacement parts. What’s missing are the rear shocks, Bilstein B46-1247s. Seems I won’t get these until May

[Kowalski2011]

6-5-23 update

My apologies for ghosting this thread, my attention was drawn away for personal reasons.
However, I have managed some time to work on the M5 a bit more lately.

Like I mentioned there was no service history other than Dr. C’s verbal regarding the fuel tank, etc. Everything is a review and discovery.
The M5s first life was in LA where I think she was dressed for the ball.
Her second life was in South Dakota where I believe she saw her share of back roading.

Here is the Good, the Bad and the Ugly.

The Good

- No rust. Doors sills, undercarriage, etc.
- Leather seats are in excellent shape
- Dash perfect no cracks
- Mileage at about 80K
- Paintwork not bad, just a couple scratches and dings
- Motor, tranny, cooling no issues, stable for over 1K miles now
- The NLA M5 grill badge is in good shape
- AC Schnitzer side skirts
- Not a 'breadbox' style rear seat (or maybe this is a bad/ugly thing)

The Bad

- Evidence of prior front end incident. The hood has been replaced and has a different VIN than the rest of the car.
- Undercarraige covers missing
- The trim panel on the front bumper is not the M-Technic that came on all M5s.

The Ugly

- Headlight/foglight glass is pitted pretty badly
- Paintwork needs a full detail
- A/C doesn’t work
- Glass-pack exhaust - cherry bombs
- Dirt everywhere in every nook and cranny (South Dakota backroads I presume)
- Evidence of street mods (LA boulevard cruiser I’m guessing)
- Aftermarket head unit, amps and speakers
- Hofco alarm and Hettel 100 park brake lock
- Shadowline trim appears to have been wrapped at one time
- Brake calipers were once painted ‘gold’ easy to see now that the flat black is flaking off
- Window tint good but slightly faded to a purplish hue
- AC Schnitzer side skirts

I had some shop time scheduled for the suspension refresh including the input drive shaft seal on the diff that was leaking. The Bilsteins remained unavailable so I opted for Koni Yellow Sports with the H & R springs. While only some suspension parts were obviously worn, I replaced all wear parts as a ‘while you're in there’ thing, now I know it’s mostly all new – I didn’t replace the beer cans.

The SLS shocks and accumulators are out. Ride height with the Konis and H&Rs is much better, some lowering but not too much.

As for wheels and tires, my plan is to refurb the M-system style 20 turbines so in the meanwhile I located a set of BBS style 5s and mounted PS4s. I gotta say they give the car that retro gangster look. I like it! Reminds me of Tupoc's murder car.

After review I’ve decided that I will not move toward a ‘stock’ set-up here. The car has been modified before so I decided a return to the former Resto Mod type refurb is the best plan moving forward.

Meanwhile in the garage I went after some other minor function and cosmetic details.

- New gas shocks hood and trunk, they were failing
- New under body covers, they were missing
- New wiper blades
- Various caps and covers in the engine bay
- Painted some plastic trim pieces and grills
- Replaced front bumper guards with euro style no side marker lights
- New headlight units, darked out style, while I try to refurbish the originals
- Clear corner/blinker lights with amber stealth bulbs
- New lighted ///M shift knob, the old one was in pretty rough shape
- Full detail, paint correction, sealant, glass polish, door handle gaskets
- Re-traced and encapsulated the amplifier wiring in the trunk
- Replaced the old ‘purpled’ tint with Llumar 15
- Leatherique treatment of leather seats.
- Fresh badges and roundels

Apologies for the long wordy post, but if you've read this far...let's look at some pictures.

I found this mess in the trunk. That crossover with an index card and duct tape - really?








In the glove box I found this EQ installed.


I replaced the worn and damaged shift knob here





New brakes and suspension parts



I replaced the cherry bombs with a new Super Sprint Exhaust system



At the shop with the Z3


Next a needed step detail. My Porter Cable RO developed a bad bearing so I upgraded to the Griot's garage G8 and G9 RO polishers. I can now run 2,3,5 and 6 inch pads. I also used their BOSS system polishes and wax/sealants. I'm very satisfied with this upgrade










More details. I painted the plastic grill and trunk pieces. Turned out great.




More shots



By the way, I've road tested the audio system, all stock speakers have been replaced and I am please to report that this set up sounds frickin' awesome! From Led Zeppelin to Robert Cray Band. WOW! OK the fact that I'm cruising down the highway in an e34 M5 might have something to do with it. I'm glad I don't have to dick around with re-wiring and/or replacing speakers.

[erickonphoenix]

Great read! Also, gross applause to your neighbor recognizing the car needed to go to a good home. I think the restomod target was spot on and really well executed. Congratz and enjoy

[lordnikon]

Very cool