BMW 20-pin Diagnostic Socket Pin-Out Diagram

Handy pin-out diagram for the pre-OBD 20-pin round diagnostic connector on 80s and 90s BMWs from PinOutGuides.com [https://pinoutguide.com/CarElectronics/car_diag_pinout.shtml] 

 

1       Engine rotation speed [TD]
2       CAN-High     
3       CAN-Low
4       Shielding
7       Oil service and Inspection reset    
11     External starter turn on
12     Battery indicator
14     Battery power     +12V
15     ISO 9141-2 L Line     
16     Ignition +12V     
17     ISO 9141-2 K Line
18     Programming line [PGSP]
19     Ground [GND]     
20     ISO 9141-2 K Line [TXD]

 

https://pinoutguide.com/CarElectronics/car_diag_pinout.shtml

BMW mid-90s E39 Coupe Concept... forerunner to the new 6 Series... and a bit of Rover 75

Another concept BMW from the mid-90s, showcasing the initial idea of a new 5er coupe based on the E39. This was also during the Rover 75 development era and I believe was even considered as a sporty version of that or the MG ZT. In the end it went on to become the E63/E64 6 Series, though those headlights sure made it on to the Rover.

BMW E30 323i Spec Comparison to contemporary early-80s rivals...

How does the E30 stack up next to its five most common early 1980s stablemates, the MG Montego Turbo, Peugeot 505 GTi, Renault 25 GTX, Saab 900 Turbo and Subaru RX Turbo?

Great review from MOTOR Magazine, November 1985.

Disguised BMW E30 concept during testing, circa-1980

Grainy pic of a quite heavily disguised BMW E30 3-Series test-mule undergoing tests in Germany circa-1980. The square headlights and covered up Hoffmeister-kink lend an interesting look to this concept, but the roofline and rear-end give it away.

Ironically, it isnt a far cry away from BMWs latest 'Neue Klasse' design language, with the forthcoming 3 seriesredesign and new electric models.

 

F10 530d: New O/S / driver’s side rear spring.

Did both of the rear struts and springs a few years ago, but find the right side one has broken right at the top and will need doing for this years MOT test. As usual with 5 Series models when the spring snaps at the top or bottom, there was no tell-tale clunking or change in driving characteristics, so who knows how long it's been like that. At least it is not a big job.

*GUIDE: F10 Rear Shock / Spring Replacement*

*GUIDE: F10/F11 Front Shock / Spring Replacement*

The rear struts were replaced several years ago from a car with 80k miles. Their combined run in both cars has still added up to less than the mileage on the original ones!

F10 530d Manual: Replaced leaking clutch slave-cylinder.

At the end of 2018 when I replaced the clutch on the F10 I threw on a new slave-cylinder while I was there, but I used a cheap spurious part, not OEM. It has been leaking for a while but I’ve started to lose my pedal and the topping up is becoming frequent, so time has come to replace it again. This time I went for an OEM Febi slave-cyl.

The spurious part from 2018 cost just £18 and is made from cast aluminium. You can see it’s poorly made compared to the OEM part, which is made of high-quality plastic. The Febi part was £57 still in 2024, but you can clearly see the improvement in build-quality. For such a critical part as the slave-cylinder it’s worth just paying the extra and avoid having to redo a messy, fiddly job!

*GUIDE: Replacing / Clutch Slave-cylinder on F10/F11*

*GUIDE: Bleeding Clutch on F10/F11*

As you can see, the cast-alloy slave-cylinder does not have the same look of build quality that the OEM plastic one does. It lasted 5 years and only about 25k miles, but was still good value for the price!

*GUIDE: Clutch Slave-cylinder replacement and bleeding guide for E30 / E28 / early E34 and E34*

BMW Option: RHD to LHD switchable controls… available to UK in the 1980s. How have I never seen this before?!

Yes, this is not sci-fi, but an actual option available to UK BMW buyers in the 80s. Driving to Europe in your E30? No problem, just fold the glove box down to reveal a left-hand dashboard, swap the steering-wheel over and off you go, all ready for continental motoring!

Belive it or not this was a common idea manufacturers were toying with back then, quite a few other marques producing concept cars with the feature, but I am surprised BMW actually built it. I doubt this was a common option and am not aware of any surviving examples.