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My 2001 2.7 had a similar problem, and it had a bit of a rattle on start up. A Porsche mechanic told me my IMS bearing was going and I shouldn’t drive the car and get the bearing changed immediately. So I pulled the engine out and took the IMS out, guess what the bearing was perfect, not even the slightest play or wear, unfortunately it had to be replaced with a new one after pulling it out. So what was the rattle? Well I pulled the Timing Chain Tensioners out (3 of them) and sure enough 2 of the 3 weren’t holding pressure, so I decided to change all 3. Then I decided while I had the engine stripped own this far I should looked at the tensioners paddles and the ‘Variocam’ tensioners. The timing chain tensioner paddles were fine with hardly any wear, I’m guessing because the ‘Tensioners’ weren’t working properly they weren’t forcing the timing chains onto the paddles so they didn’t really wear. But the biggest surprise was the ‘Variocam Tensioners’, they were both stuffed! And after pulling them out I decided to cut them in half (they’re a sealed unit) to see what had happened. When I cut them open the first thing I noticed was the deterioration of the ‘O’ rings, and there was thick phenolic seal that had worn the case hardening on the bore of the tensioners, and this affected the operation of the Tensioners. After replacing all 3 timing chain Tensioners and the 2 Variocam Tensioners plus the wear pads on the Variocam Tensioners, the car was like new again, NO rattle on start up and when I took it for a run I noticed straight away the ‘increase’ in low down ‘torque’, it was truly astounding what a difference it made to the car’s performance!
The variocam tensioners and timing chain tensioners are as big if not a bigger issue than the IMS. As I said with 150,000kms on my Boxster, the IMS was in perfect condition, but the tensioners were shot!
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