Over time Porsche timing chain tensioners may weaken, causing a rattle for about 5 seconds at startup.
One of the most common issues that cause Porsche engine noise for about 5 to 10 seconds on startup is a weak timing chain tensioner that is not maintaining hydraulic pressure when the engine is turned off and parked for an extended time.
In this guide, we go over the instructions on how to change Porsche left lower timing chain tensioner with the engine in the car.
Pictures in this guide are from a Porsche Cayenne with V8 engine, but the procedure should help you change the tensioners on other Porsche models as well.
Always replace one tensioner at a time. Check your work by turning the engine by hand two full revolutions.
In some cases, a rattle noise is present when the vehicle is parked for several weeks or months. This is normal unlesss you experience engine noise on start up when the vehicle is parked overnight.
It is recommended to get your car diagnosed by a professional Porsche mechanic to confirm the tensioners are the culprit.
Another common problem on Porsche vehciles is IMS bearing failing and is often misdiagnosed as a bad timing chain tensionner.