A failing fan clutch might cause:
* Increased engine noise: A bad clutch might make the fan freewheel at high speeds, causing a whining or howling sound.
* Overheating: The fan won't engage properly to cool the engine, leading to overheating. This could eventually cause rough running if the engine suffers damage due to the heat, but it's an indirect effect.
While a severely damaged fan clutch *could* indirectly lead to rough running by causing engine overheating and subsequent damage, it's not a direct cause. If your Astro is running rough, focus your diagnostic efforts on the more likely culprits mentioned above.
