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smokintr6 smokintr6 is offline
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1: If it is piston slap you will be able to tell without a doubt by placing a stethoscope on the cylinder fins... or use the "screw driver trick" if you don't have listening tools.

2: Steve, it's interesting that you say the Mahle pistons run dead silent, when I was doing some research post build (on my 964 3.6) I seemed to find people saying that the stock pistons would slap if they were any looser than center spec on the piston to wall clearance. I have some piston noise on mine, again only when it's cold, and when I went back and checked the data all the pistons were out to the loose side of the clearance, and one was actually in spec due to rounding at the .000X" decimal place. I assume this is why I get some cold piston slap, and I will end up tearing it down at some point for P&C work.

3: If they reused your P&Cs I don't see how you can really come back to them for warranty work on the used parts, IF it is a piston slap noise. It doesn't make sense to me that the noise is new, unless they botched the cylinders up trying to recondition for new parts.

4: Ask them what the piston to wall clearances were, and what they would accept for reusing parts. Technically what you paid them for in this are was their expertise in part fitting, You might have paid for bad advice, but unless they were negligent, I'm not sure you have recourse to try to make it quieter. The fact is if you wanted nee P&C the rebuild would have been MUCH more costly. You could possibly ask for help with the added labor, but I think you'll be on the hook for the parts cost.

5: since they did do bearings you want to make darn sure it's not a rod noise. There have been Glyco rod bearing problems on these engines. Ask if they were Porsche OEM bearings, or Glyco, and ask what clearances they targeted. Double check for piston slap noise with your stethoscope and make sure its not coming from the case!!

6: I'm not pretending to know more about these things then steve... he's built a LOOOT more of these engines than I ever will!
Old 04-03-2018, 11:58 AM
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