Hello,
My 996TT has developed an intermittent rattling noise. It comes and goes suddenly and it is hard to pinpoint what conditions cause it. If anyone has experience with this issue, I would really appreciate your insights.
So far, I have gathered the following data and observations using the Durametric tool:
• Actual Angle of Camshaft on Bank 1 and Bank 2 are similar (see below).
• Cam Position Deviation on Bank 1 and Bank 2 are very different (see below).
• Fault Code P0021 (Porsche Fault Code 325) - Camshaft position with respect to camshaft bank 2.
• When I activate the Valve Lift control test there is quite a bit of noise, and it is more pronounced from Bank 2. (I tested them individually by disconnecting the Valve Lift Solenoids on either side).
• I disconnected both Bank 1 and Bank 2 variable valve timing solenoid and there was no change.
From what I have researched the issues could be caused by:
• Bank 2 intake camshaft has loosened
• Bank 2 intake camshaft sleeve has rotated causing the blockage of the oil passages
• Bank 2 camshaft oil housing is worn
• Bank 2 chain has stretched
• Bank 2 chain tensioner has collapsed
• Chain ramps are worn out
• Intake tappets are sticky or defective
I will pull the motor in the next week and inspect the cam timing, tappets, chain guides, etc. In the meantime would really appreciate any insights from anyone with experience with these issues. If this is of interest to anyone I will post my progress.
Thank you,
Jeff
