i was wondering where that wire that goes on the complete opposite side of the engine it looks like a rpm pickup id like to change my wires on my 1990 525i but i dont want to even start pulling them off unless i know there the other wire goes to.

thanks

On my 89 525i it goes over to a connector on the intake side of the engine under the intake manifold. Like you, I think it is a "pickup" wire to pull pulses off of one of the spark plugs, probably for feedback to the computer.

My new plug wires (Bosch from AllEurasianparts online) came complete with new pickup wire, and a new coil wire also so it was no problem to trace the wire over and just connect the new one.

Regards,

ShadeTreeBill