The 50mm asbestos-free exhaust flange gasket (Part #18301716888) is common across classic BMW platforms. It primarily fits 1991 to 2001 BMWs equipped with inline-six (M50, M52, S50, S52) engines, as well as the flagship V12 (M73) models. It serves as the critical crush seal where the exhaust headers collect and dump into the catalytic converter inlet pipes. While the official internal factory bore spec is exactly 50mm, the actual stamping of the metal reinforcement rings or the flared tail of the exhaust piping itself can occasionally measure out closer to 51mm or 52mm with a digital caliper.
I have 2 standard material 3-bolt gaskets and 2 that are a heavy duty version made of steel (see pics). A steel gasket is being supplied at no charge with the fiber gasket. Buy both and I'm sending you 4 gaskets.
| Chassis |
Model |
Model Years |
Engine Spec |
| E36 |
325i / 325is / 325ic |
1992 – 1995 |
2.5L L6 (M50) |
| E36 |
323is / 323ic |
1998 – 1999 |
2.5L L6 (M52) |
| E36 |
328i / 328is / 328ic |
1996 – 1999 |
2.8L L6 (M52) |
| E36 |
M3 (US Models) |
1995 – 1999 |
3.0L / 3.2L L6 (S50/S52) |
| E34 |
525i |
1991 – 1995 |
2.5L L6 (M50) |
| E39 |
528i |
1997 – 1998 |
2.8L L6 (M52) |
| Z3 (E36/7) |
Z3 2.8 Roadster / Coupe |
1997 – 1998 |
2.8L L6 (M52) |
| Z3 (E36/8) |
M Roadster / M Coupe |
1998 – 2000 |
3.2L L6 (S52) |
| E38 |
750i / 750iL |
1995 – 2001 |
5.4L V12 (M73) |
| E31 |
850Ci |
1995 – 1997 |
5.4L V12 (M73) |
Quantity Required - Inline-six models feature a dual downpipe layout and require two of these gaskets to complete an exhaust drop. V12 platforms utilize four headers collecting into dual exhaust runs, similarly utilizing multiple rings.
