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1989 964 C4 Reseal Followup


Vehicle Information: Year: 1989; Body Type: Coupe; Total Mileage: 120000;

This is a followup question I submitted on 3/26/04 on a reseal job that has metal in the crankcase oil drain.The original shop has the car and after taking off the timing chain found the master link that is missing an e clip. Further, they took off the cam housing&Valve assembly as one unit and took off the #2 cylinder spring with some older 911 tool. Having found no cause of the problem they split the case which showed no failing part but did have metal in it and the filter. They removed the valve assembly and determined that the number 2 exhaust valve did not move smoothly and that the valve stem seal was most likely gone versus removed by them. They further noticed that a couple of valve stem seals were moved up on the valve guide. They further talked with Memphis MotorWerks and they said the only way the valve stem seals could be high on the valve guide was if the engine was over-rev'd. They further detemined that the valve fit 2 marks (not shiny marks) on all the pistons where the valves supposedly struck the pistons.I did not over'rev this car. But won't an over rev situation whereby the piston was struck make the car idle very rough and not rev up smoothly. This car was initially driven to the Porsche Dealership and they said the engine was running smoothly.Are their "fly cuts" in the 3.6L 1989 964 engine and that is what this shop is looking at?This 911 shop is now going to send the valves back to Memphis MotorWerks to check if the valves are bent and if the valve guides were the wrong length.Again, do valve stem seals move up the guides if the engine is overrev'd? And would the engine run smoothly although have tapping noise if the valves struck the pistons? This seems too weird for me. The only additional response they offered was that since I have a Patricks Motorsports lightweight pressure plate my engine revs up fast and can overrev.

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