What happens if the tensioner doesn't spring back?

If the tensioner doesn't spring back, it can lead to insufficient tension on the timing belt or chain, potentially causing slippage or misalignment. This can result in poor engine performance, increased wear on components, or even catastrophic engine failure if the timing is disrupted. Additionally, a stuck tensioner may cause abnormal noises or vibrations in the engine. Regular maintenance and inspection can help identify and address tensioner issues before they lead to serious problems.