SOLD Z3 rear springs, twin green paint marks £40

[Andyboy]

As above in very good condition and not that old. From a 1.9 but clearly not the originals from 1997 and almost certainly not Sport springs - I've no idea what the paint marks signify.

 

[Nodzed]

The splashes of paint or coloured dots on factory vehicle coil springs are part identification codes. They tell factory workers and mechanics the exact spring rate, wire thickness, length, and load capacity meant for a specific vehicle model, engine size, or package option

 

[Andyboy]

I was referring to what two green marks actually mean in terms of the car spec.

 

[Nodzed]

I was referring to what two green marks actually mean in terms of the car spec.

Yes I realise that. Good luck trying to find that out, best I could find was stock springs for a 1.9 on some random thread on a site I'd never seen before that wasn't overly convincing

 

[Andyboy]

Realoem and BMW Fans doesn't tell you anything either.

 

[Peewee]

These could well be genuine BMW springs. Part numbers 3353 9070476 or 3353 1094169 from a standard 1.9.
A clue to being OEM is that they are not constant wire diameter (thinner wire at the ends) which gives a progressive spring action. Aftermarket springs are nearly always constant wire diameter, as they're easier to make. What the green paint marks actually mean I don't know either!

 

[Mazza]

PM sent

 

[Peewee]

I've managed to do some detective work. Colour coded paint marks on the springs relate to the spring stiffness. There are different colour codes for springs of different stiffnesses but all under the same part number. This allows a spring stiffness to be selected to match the weight of the car so that the ride height meets specification- i.e. options such as manual/automatic, air conditioning or not etc. which affecr the weight.

I haven't been able to crack the colour codes, but I suppose this is where the mysterious BMW Z3 spring configurator comes in (BMW dealer?)

However, as far as I can see, the double green on these springs relates to a standard 1.9 manual with air conditioning. Clearly they are not the original springs though.

Hope this helps.
Peter

 

[Andyboy]

Thanks!