E28 technical advice asked and given! Troubleshooting, modifications and more.
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Post by nnarth212 »

Forgive me-- I snatched a bit of another users post, DJM1986-5, I believe.

I would find it useful to take this list and provide a link to the best known procedure for each... Once we have it sorted, perhaps a sticky would be in order. Or it may belong in the TECH FAQ.

Recommendations appreciated and thanks for any support.

From the forum:

"Someone please start a sticky that says "BASE LINE YOUR E28 BEFORE POSTING - HERE'S HOW"
A1 - Replace all fluids and filters - diff, trans, master, engine, coolant.
1. Replace all vacuum/intake rubber

2. Replace all engine comp. fuel hoses

3. Replace cap, rotor, inspect plugs etc.

4. Inspect and tighten every fuse in the block + main and FP

5. Replace CTS, test TTS.
Test TTS: ... t=test+tts
6. Clean IASV - test, reclean etc ... clean+iasv
7. Retrack and/or test AFM for dead spots
8. Replace air filter

9. Adjust valves and tighten oiler bar

10. Unscrew, clean and re-tighten all grounds on car.

Rod Paine:

E28 Ground Distribution

Compiled by Rod Paine from the
1983 BMW 528e / 533i Electrical
Troubleshooting Manual Circuit
Diagrams, July 2004

G102, on LH fender behind LH headlights
is ground for:

- Battery
- LH Turn/Park Light
- LH Horn
- LH High Beam
- LH Dual Beam
- RH Horn
- LH Fog Light
- RH Fog Light
- RH Dual Beam
- RH High Beam
- Coolent Level Switch (528e ONLY)
- Washer Fluid Level Switch
- RH Front Turn/Park Light
- LH Front Marker Light
- RH Front Marker Light
- High Beam Relay
- Low Beam Check Relay
- Aux Radiator Fan Motor
- High Speed Motor Relay
- Normal Speed Motor Relay

G103, above starter motor on engine block
or intake manifold stud is ground for:

- Purge Valve
- Throttle Switch
- Main Relay
- Idle Speed Control Unit (533i ONLY)
- Idle Speed Control Unit (528e)
- Motronic Control Unit (7 ground wires)
- Flywheel Sensors cable shield
- Coolant Temperature Switch
- Coolant Temperature Sensor
- Filter Capacitor
- Oil Pressure Switch

G200, under LH side of dash near brake
pedal, is ground for:

- Auto Trans Range Switch
- Instrument Cluster Circuit Board
- Cruise Control Actuator
- Cruise Control Control Unit
- Rear Defogger Switch
- Power Window Relay
- Light Switch
- Ignition Switch
- Wiper Washer Switch
- Flasher Switch and connection to G201 ground point.
- Passenger Mirrior
- Drivers Mirror
- LH Front Door Lock Actuator
- Lock Heater Control Unit
- Mirror Control Switch
- Seatbelt Warning Timer
- Coolant Level Switch (533i ONLY)
- Hydraulic Pressure Switch (533i ONLY)
- Brake Accumulator Switch (5331 ONLY)
- Brake Fluid Level Switch
- LH Front Brake Rotor
- Wiper Motor
- Interior Temp Sensor
- Drivers Window Console Switch
- LH Rear Window Console Switch
- Trunk Lock Actuator
- Central Locking Control Unit
- RH Front Window Console Switch
- RH Rear Window Console Switch
- Glove Box Light
- Evaporator Temp Regulator
- Evaporator Temp Sensor
- Heater Temp Sensor
- Heater Regulator
- On-Board Computer
- Blower Speed Switch
- Evaporator Blower Resistors
- Hazard Switch
- Digital Radio
- Chime
- Cigar Lighter
- Auto Charging Flashlight

G301, under LH side of rear seat
is ground for:

- LH Rear Light Assy.
- LH License Light
- RH License Light
- Rear Lights Check Relay
- RH Rear Light Assy.
- LH Rear Side Marker Light
- RH Rear Side Marker Light
- RH Rear Brake Rotor
- Fuel Tank Sender
- Main Fuel Pump
- Auxiliary Fuel Pump
- Rear Window Defogger Element
- Interior Lights Timer Control

11. Flush coolant system, ensure fan clutch works, replace t-stat, test aux fan sensors, replace water pump.
Mileage? ... sh+coolant
12. Flush power steering fluid, replace filter, check hoses for leaks, replace top low pressure hoses.

Nnarth212:Rebuild shop?
FOR Nor Cal
W K Hydraulics Inc
1820 Arnold Industrial Wy Ste F
Concord, CA 94520
(925) 676-6047

13. Replace fuel lines 8mm and 12 mm ID at tank

14. Now read Rod Paine's site about suspension work.
15. Replace suspension brake components as necessary:
>Inspect, clean, replace rebuild brakes, calipers, rotors and lines if cracked or stiff.
>Subframe bushings - Meyle or Lems
>dog bones - Meyle or Lems
>Diff Mount
>sway bar links rear
>S. B. links front
>tie rod ends or complete unit -test and replace
>Idler arm
>Upper control arms - Meyle HD or better, 750 bushings
>Center link
>Lower control arms
>Check shocks/struts/springs - replace with Boge or Billies depending on your flavor
>Check springs - Eibach, H & R, etc.
>Replace strut bearings, spring pads, inspect perches, clean weep holes etc etc.

16. Lather, rinse, repeat.

OK, I have office work to do. Someone may pick this up and run with it. I may price this out some time. List is somewhat in order of immediate importance, but that varies by car upon inspection."

17: Steering box mount repair: ... sc&start=0
Last edited by nnarth212 on Jun 15, 2011 4:05 PM, edited 1 time in total.
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Post by Sparkeysf »

Great idea! I've had this list stickied on my own desktop and have been slowly working my way through.
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Post by lmc337 »

X2 for sticky, and surprised a) I missed it and b) there aren't any additional posts. Excellent start, DJM1986-5 and V1cut were the two I recall from a few months back putting the lists together. I know David (djm) has a spreadsheet off the costs somewhere, and I'll threaten to lock him out of the shop if he doesn't jump in and put the faq together properly :D
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Post by DJM1986-5 »

ok, I'm working on it! Actually I'm workng on a spreadsheet with this list and sevice intervals on it - what to do when for newer owners and older ones to. 535, 528e. and costs too...cross referenced with where to buy and what brand(s)

Sound good?

DJM(can i get back in the shop?)
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Post by Dan_Wright »

I just copied this from an old thread to a notepad, this is great stuff.
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Post by rodpaine »

Last edited by rodpaine on Sep 30, 2010 7:20 AM, edited 2 times in total.
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Post by rodpaine »

Very good idea!
This file shows the grounds typically associated with the various devices. You may also want to include this link which talks about other common electrical problems.
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Post by tock172 »

DJM1986-5 wrote:ok, I'm working on it! Actually I'm workng on a spreadsheet with this list and sevice intervals on it - what to do when for newer owners and older ones to. 535, 528e. and costs too...cross referenced with where to buy and what brand(s)

Sound good?

DJM(can i get back in the shop?)
That would be awesome! I am looking forward to seeing this.
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Post by TSMacNeil »

I remember having this conversation awhile back and forgot to print it for my records( I'm a geek that way)
I finally found the original, courtesy of DJM1986-5 enjoy:

"OK, pardon us while we momentarily hijack the thread. To all new and some current owners of E28s, please inspect the obvious upon taking delivery of your E28 and certainly in the days and weeks following...unless you bought it from Gray635 or wkholer or other noteworthy, otherwise famous and reputable owners on this site... "

Check and replace suspect:
Spark plugs
Cap and rotor
Spark plug wires
Vacuum hoses
Intake boot and IASV hoses/connections
Fuel lines - engine compartment
Fuel line to cold start valve
Fuel lines - rear gas tank
Gas Tank for rust
Fuel filter
Air Filter
Change oil regardless
Inspect for oil leaks
Inspect PS hoses and switches for leaks
Inspect Master cylinder and connections for leaks
Test Alternator output 13.7 - 14.8 V
Test alternator shaft for wobble
Test battery for proper voltage 12.6 - 8 V
Coolant hoses
Water pump - test shaft for play or slight wobble
Radiator (drain, flush with engine block drain removed)
Inspect and/or replace T-stat
Clean Idle air stabilizer valve
Inspect and clean (if necessary) AFM
Test TPS switch
Test every sensor on the T-stat housing as applicable:
Coolant Temp Sensor (blue on 535/528, white on 533)
Thermo Time switch (brown plug)
Engine Temp sensor (one or tab brass dep. on E28)
Purge valve (2 small hoses on it)
Adjust valves (eventually)
Check for leaks at injectors and eventually have reconditioned.
Inspect fuses for correct Amp 8, 16, 25 and tighten connections.
Inspect all belts for condition and tension/deflection
M20 - timing belt & tensioner

This is outside of inspecting the suspension (UCAs, LCAs, steering linkage, dog bones, sub-frame bushings, brakes and brake lines, rotors, brake bleeding especially if car's been sitting for a while), etc etc.
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Thread resurrection

Post by Mab1957 »

Resurrecting this after talking to David & John at The Vintage about base line efforts to our e28. We'd still love to see a spreadsheet or table with all the links to processes and parts. I don't find it searching on 'base line' in Tech Talk or Tech FAQ.

If nothing else David's list is very helpful.

Thank you.
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Post by tn535i »

Somewhere before all this time and expense there should be a compression (maybe leakdown) test to make sure it's not a waste of time and expense.

Then while replacing all this stuff above you should also send out your injectors for cleaning and balance test then install with new caps and o-rings.

We talking about bringing a good example of an e28 back to 100% right? Not for the faint of heart or those with a thin wallet.

Be clear that brake fluid needs to be bled till clear at each wheel and the clutch slave not just the master replaced.
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Post by nik77356 »

Found this thread while searching for info on diff mounts. Seems like this could be a good thread for the Tech FAQ section?
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Post by shagrath »

This is almost like recreating a service interval checklist for modern use of e28's. Keeping the service info updated for keeping an e28 in the modern age. I like it!
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Post by unt0uchable »

I search PARTICULARLY for this thread for about a week and then finally gave up. Me wonders why it never came up.... weird. Thank you for finding it for me! I now have a checklist. :banana:

Paul in N FL
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Post by Paul in N FL »

Beamters please apply tape to this thread and post it at the top!
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Post by tn535i »

Might add check brush length on voltage regulator ?
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Post by TSMacNeil »

This is brilliant. A baseline crib sheet with links for all the tests?
Priceless. Do you realize how many newbs we could just point to this one living document? We need to finish it up and sticky this bad boy.
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Post by Chimi-Changa »

hmmm- also heard to replace all relay's ( I write date on them) keep good one in glove box?

These places may also help with tips and technique, thought it would be nice to have on this thread for quick access-
Good place for maint and known things to look for and replace:

Rod Paine's page has been a constant great source too:

idle info by Sam Chien-shin Lin:
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Re: Baselining...

Post by Burnze »

Re-Re-Resurrecting thread. This is great stuff for all new owners. I've been slowly going down the checklist the past 3 months.
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Re: Baselining...

Post by EricF »

Great info and links in here! Thanks!
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Re: Baselining...

Post by davintosh »

Back up from the depths... Did anybody ever assemble & publish a reasonably comprehensive baselining checklist? I've been searching, but not coming up with much of anything. Lots of tidbits, but...
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