Road trip story & Project thread: 2001 Titanium Silver e39 M5

[fredo]

+1. Congrats on your great progress !

[ZHPizza]

Damn that is some amazing investigative work and rebuilding. I don't know how you're getting anything done over there right now with your 5 hours of daylight.

[Sreten]

Dude. I’m in awe of your ability to not only fix the issues you fix, but to seemingly do so with such calm and logic. If I found that hack job you just resolved I probably would’ve gone inside, defeated, and consumed a large quantity of beer. Meanwhile I’m still driving around without an ambient temp sensor because the carport is too cold and damp for my sensitive bitch-self to crawl under one corner of the car for 15 minutes and splice the wires back together.

Marvelous update, as always, my good man.

Thank you, Spenser!

It wasn't going swimmingly as it may seem and after finding this hack job, consuming large quantities of beer is exactly what I did while kicking myself trying to understand the reasoning behind this idiocy. Still got nothing... I tackled it another day after doing some reading up and ordering new parts.

I honestly wasn't sure if I was going to get the car up and running, the fact alone that is was parked for 10 years or so and then to find hack jobs wasn't encouraging, but I persevered and it was a proud fuck yes moment when I drove the car out of the garage. Totally worth it.

I can relate, when the weather is like this you just don't have the motivation to go out and fiddle around the car.

+1. Congrats on your great progress !

Thank you, Fredo!

Damn that is some amazing investigative work and rebuilding. I don't know how you're getting anything done over there right now with your 5 hours of daylight.

Danke schön, Herr Pizza! We are past daylight son, just me after work in a stinky ass underground garage with my trusty magnetic torch light tinkering away while normal people walk past me with the word lunatic in their mind, I shall imagine.

I told myself this is the last time I'm starting this type of a project in a miserable not well-ventilated space. Poisoning myself with all that crap just doesn't bode well for my health.

[704sw]

Information on the “trusty magnetic torch light?” Sounds like a good solution to my work-lighting problems.

[Sreten]

I bought an equivalent to this one on German Amazon. Pretty good light output, easy to maneuver and the magnet is very handy.
I think I can get around 3 hours of usage with full light output and I'm planning to get another one to use while the other one is recharging.
https://www.amazon.com/gp/aw/d/B07BQ...L65&th=1&psc=1

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[johnrando]

Wow, awesome detective work and mechanical skillz.

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[BMWCurves]

+1 on Spenser's comment. I would like to think I would persevere like you did, but let's be honest, I would have flung my hands up in annoyance and just given up.

It's awesome you're bringing this thing back to life, outstanding work, especially considering your work space/environment. Simply top notch stuff, bud!

[Sreten]

Wow, awesome detective work and mechanical skillz.

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Thanks, John! Been a while since I had to do so much troubleshooting and testing, usually you just plug in the scanner and it'll tell you what's wrong. Not always the case with this old beast.

+1 on Spenser's comment. I would like to think I would persevere like you did, but let's be honest, I would have flung my hands up in annoyance and just given up.

It's awesome you're bringing this thing back to life, outstanding work, especially considering your work space/environment. Simply top notch stuff, bud!

Appreciate it, Will! There were moments when it crossed my mind to throw in the towel but I'm glad I didn't. I learned a lot about E31 and common weak spots on the M70 engine in the process, makes me feel a bit more comfortable working on it. Would love to get my hands on E38 with M73 lump in the front too.

I have to move both of my cars out of the garage by 15th of Jan due to renovation and I haven't found anything promising yet, should be fun.

[Sreten]

Update on the M5.

A couple a weeks ago we went to France for the opening of the Christmas market in Strasbourg and Colmar.

On the way there M5 decided to greet me with its own set of Christmas lights.



Pulled to the gas station, restarted the car and lights went off and didn't come back until following weekend when we went to Heidelberg to drink more Glühwein.

In the meantime, I pulled the codes and it was for the front right wheel speed sensor. Quick visual inspection revealed exposed wires on both sides so time for a new set. These are likey the original sensors.





There are various brands for wheel speeds sensors in Germany. I went with Bosch: part # 0 986 594 508 - around $40 per side. Great quality and surprisingly made in Germany.



Didn't take any pictures here since this a straightforward DIY. Instead here's a complementary picture of lovely D2Racing 8 piston brakes.



Hood struts were getting weaker, that was a nice-easy-cheap fix.



When I had the belts off last time, I noticed that the alternator bearings were noisy when I spin the alternator pulley. They weren't particularly bad and I couldn't hear them with the car running but I wanted to sort that out before getting worse.

On this side of the pond, cheapest rebuilt M5 alternator starts in the 4 digit range which I thought was hilarious so I opted to replace just the bearings and voltage regulator just like Ed China did. Besides, this is a perfectly good working alternator so scraping it would be a crime.

This isn't a terrible job but it quickly becomes annoying if you don't have the right tools which tends to happen to me. I had to make a run to the hardware store a couple of times so I'll include some tips if anyone else attempts this job and hopefully make it a bit easier.

Before getting started, I measured the voltage with the car running for before/after comparison. Readings of a healthy alternator.



Removing the alternator is the easy bit - remove the fun clutch, drive belt and upper belt pulley to get access to the alternator bolt. Unbolting the PS pump is so easy that I didn't want to try it any other way, there are only 3 bolts holding it and then you can slide the pump out of the way and wiggle the alternator out. Trickest part is to loosen the negative cable on the back of the alternator but it's doable with an open-ended 17 mm wrench.



It's heavy so don't drop it on your face if lying under the car as I did.



I bought a set of el cheapo gear pullers for this job. The nut holding the pulley removed with an impact wrench and ready to pull off the pulley.



It comes off rather easy.



Working on the back of the alternator, plastic cover and voltage regulator removed.





There are 4 bolts holding the case together and once those are removed, it comes apart easily by prying and separating two halves with a flathead screwdriver.

With the rear case of the alternator removed, the rear smaller bearing is exposed. The plastic cap needs to be taken care of which is visible on the right side of the picture.



Removing the bearing with a puller.



Original bearing made by NSK. This one wasn't that bad and was spinning okayish.



I ordered new Bosch bearings, but as Bosch doesn't make them the bigger one is made by NSK and the smaller one by SKF. Both are good quality bearings.

Part numbers:

Bigger bearing - Bosch Part# 1 120 905 510 is common part# B17-99D (17x52x17)
Smaller bearing - Bosch Part# 1 120 905 525 is common part# 6203-2RS (17X40X12)



New bearing gently tapped on.



Coming back to the front of the alternator, we have 4 Philips screws securing the front bearing to the case. Before I started this job, I read that these screws are a pain and almost always melt.
Despite that, I didn't get screw extractors, so learn from my mistake and be sure to have them for this job.

I approached them with care, soaking them in WD-40 but they still melted on me. This is where I had to stop, get a beer and make a run to the hardware store on Monday when they open.

image uploader

Equipped with proper tools, got the bastards out.



Original screws are odd length, 22-23 mm and the replacement once I got are M4 x 20.

25 mm should also fit, but the hardware store didn't have them in stock. This was the 2nd run to store as I didn't know their spec prior to pulling them out.



With these removed, the rotor can be tapped out from the front case, a steady surface is needed for this.



I always find my self in work with what you have type situation and in spirit with that tradition, I decided to use my girlfriend's yoga blocks as a soft surface to prop the rotor while I work on the bearings.

Totally ruined them.



Next tip - there is very little space to grab the front bearing and jaws on my cheap puller were too thick to fit. Wanting to avoid another delay and ordering of new tools, I ground down the surface on my puller and I was able to fit it properly.





The big bearing is stuck on there pretty good and this is where you need to grow a third hand. I had to employ help of my girlfriend to turn the ratchet while I was holding the guts of the alternator.

Front bearing removed.



This one is made by NTN. It was in poor state and main source of the noise.



Repeated the same gently tapping installation for the new bearing and then assembled the casing back together.



Lastly, I bought a new voltage regulator since I'm already in there and the old one was bound to have worn.

I got really lucky and stumbled upon original Bosch regulator on German Amazon for unbelievable $45! Last one and these are normally well over $400 from the dealer for the same Bosch part.

BMW part # 12311713491 / Bosch part # 1 197 311 545











One noise free alternator ready to go back in the car.



Reinstallation went swimmingly to the point I almost couldn't believe how smooth I was able to pop back the alternator. That never happens.

Verified that the alternator is doing what it's supposed to do and went for a shakedown on die Autobahn. It didn't fall out and was still charging properly, job completed.



Few christmassy pictures from France.

























Happy holidays, folks!

[san]

I admire how you have the patients to take pictures even when things are not going right. I just can’t be bothered to take pictures even if it’s smooth sailing...


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