Pistons And Piston Rings
WARNING: This page is about a different car, the 2018 BMW 330i xDrive, 2018 BMW 330i, 2017 BMW 330i xDrive, and 2017 BMW 330i. However, it is still accessible from the selected car via links, so may be relevant.
| Original piston dimension (new piston) |
81.978... 82.016 mm |
| Piston installation clearance (new piston) |
0.03...0.17 mm |
| Piston installation clearance (worn piston) |
0.2...0.20 mm |
| Permissible total wear tolerance between piston and cylinder (engine operated) |
0.25 mm |
| End clearance of center piston ring |
| Before measuring the end clearance, make sure the cylinder is within the permissible tolerance. |
0.30 mm...0.45 mm |
| End clearance of upper piston ring |
| Before measuring the end clearance, make sure the cylinder is within the permissible tolerance. |
0.15 mm...0.25 mm |
| Side clearance of center piston ring |
| Clean all components before measuring the side clearance. |
0.07 mm...0.11 mm |
| Side clearance of upper piston ring |
| Clean all components before measuring the side clearance. |
0.07 mm...0.11 mm |
| Original piston dimension (new piston) |
81.978... 82.016 mm |
| Piston installation clearance (new piston) |
0.03...0.17 mm |
| Piston installation clearance (worn piston) |
0.2...0.20 mm |
| Permissible total wear tolerance between piston and cylinder (engine operated) |
0.25 mm |