Q: I have a 2001 Carrera and I wonder why my clutch is working poorly following a service. I never had any problem with it before I took it in for the 30 K service but the advisor mentioned that it felt “grainy” and weak. I wasn’t too worried about it since I was going to put the car away for the winter but when I went to pick it up, it was noticeably slipping and it wasn’t doing that before.
When I got the car I was warned that the clutch and brakes are two areas that I should plan to fix but I wasn’t expecting to get the car back with a clutch that didn’t work. I never track the car and I thought I was easy on the clutch. I trust the guy but I have to wonder if he is playing me straight. – Charley
A: Charley, thirty thousand miles on a clutch is not normal but since you bought the car used, it’s possible that the first owner abused it and you just inherited the problem. So don’ t beat yourself up, but I wonder about your comment that you are “easy on it”.
From my perspective, being easy on it means getting your foot off the pedal as quickly as possible and not allowing the clutch to slip. But to most folks this is counter intuitive. If you believe the revving the engine up and slowly releasing the clutch pedal is being kind to the clutch, you are dead wrong!
The only time a clutch wears is when you are starting off or during shifts while you rev the engine. When the car is in any gear, with the clutch fully engaged, it undergoes no wear whatsoever. It just spins merrily around connecting the crankshaft to the transmission. And the “easier” you are with it, and the more throttle you feed it while it is slipping it, the more wear that occurs. I have seen clutches live 7 thousand miles, 12 thousand miles or 170 thousand miles. It all depends on the driver, not the clutch. As an aside, automatic transmissions have clutches too. The reason that they don’t fail, is that the computer controls how much slip or grip to apply, not the driver.
When a clutch pedal starts feeling rough or vibrates that usually means that the clutch has been abused or overheated. The pedal should feel smooth as glass when depressed or when released, never grainy. Roughness can be caused by clutch system components which lose their integrity due to heat. My hunch is that your clutch was weak when the car was serviced and then it was probably stall tested. That will bring out the worst in a marginal clutch.
Technicians perform a stall test to determine the relative strength of the clutch. At about 30 miles per hour, the clutch is depressed, fifth gear is selected, the engine rpm’s are held at about 3,000 and then the clutch pedal is quickly released. If the clutch is healthy, the engine rpm’s will immediately drop as the clutch is “loaded”. If the clutch is weak, the rpm’s will not drop and the car may actually slow down while the engine revs up. What follows is an acrid odor of roasted clutch friction material. And that is a very nasty odor…like the smell of burning money.
When the clutch is dismantled, the disc will probably be worn down to the rivets or oil soaked. The damage should be obvious. If you have concerns about the advice that you are given, ask to see the parts and take them with you. A second opinion should ease your mind.
If the clutch has oil on it, don’t be surprised. Whenever the transmission is removed from your generation Porsche, request that applicable technical service bulletins be accessed to nip any other related problems in the bud. On this model, there is one in particular that recommends resealing of another potential leak source at the end of the engine block. Don’t be surprised if the engine main oil seal has failed since the original part number has been superseded three times! The latest and best seal is a new design Teflon seal that is used in many applications in Porsche, VW and Audi. I have no doubt that this seal will be the last one your engine will need if properly installed. – MC