This is a genuine BMW spacer, part number 13 51 2 245 251. The number stamped on the part is 13512245251; BMW's catalog files it under the short number 2245251. You will find it on our Air Intake shelf, under Injection pump, control part, mixture c..
It fits the E36 sedan and touring (325td and 325tds, 1991–1996), with the M51 engine. It also fits every E46 body style (316i, 316ti, 318i and 318ti, 2001–2003), with the N42 engine.
BMW draws it on 5 diagrams, among them Engine block (11_1177) and Engine block (11_4822). It weighs about 60 g (0.1 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.