All parts › BMW M4 CSL › S58 engine › Belt drive › Belt tensioner
Belt tensioner
Part of Belt drive · about $120 to replace
What it is
Spring-loaded arm with idler.
What it does
Keeps belt tension constant as the belt stretches.
How it fails
Bearing noise at idle.
| Material | Steel spring, plastic pulley |
|---|---|
| Spec | 400 N nominal |