Sounds like a decent mechanic..
I said about a week ago:
I'm surprised he didn't mention a warped clutch disk, that isn't really uncommon.. and has the same effect as a warped pressure plate.
Sounds like a decent mechanic..That is a good point. The shop changed the trans fluid 200 mi ago. I assumed they added it correctly but it wouldn't hurt to check. I think I'll do that over the weekend.
I spoke to my buddy who's a Porsche mechanic. Based on the summary above, he said the trans needs to come out to inspect the clutch assembly. He suspects a defect or cracked pressure plate, hence the intermittent issues described above. If there is nothing worn in the clutch assembly then the transmission is the culprit.
Porsche does not service transmissions, they just replace them🥺.
He gave me the name of a reputable shop owner in Santa Monica who I will call in the morning to discuss the next steps.
I'm surprised he didn't mention a warped clutch disk, that isn't really uncommon.. and has the same effect as a warped pressure plate.the OP also said "The squeaking noise disappeared but the clutch has a weird springy binding sensation when you push it in slowly. " - that rather obviously indicates some issue with the clutch releasing. A bad pressure plate? A warped clutch disk? A bad slave cylinder? Lots of possibilities, just needs someone who knows what they're looking at to sort it out.
I want to correct this ancient bit of misinformation that gets repeated ad infinitum on the Internet. GL-5 fluids are fine, and in fact Porsche issued a TSB in 1988 stating that "Transmission oil labeled API Service Classification GL 5 or MIL-L 2105 B must be used on all Porsche models," their bulletin 8813. The issue with the chemistry of really early GL-5 fluids was resolved a long time ago.Did the original shop ever change the transmission oil? (You mentioned it in the original post, but it's not clear when they did this.) If so - is there any record of what they used? As a general point - use of GL5 oils is not encouraged in transmissions. Most GL5 oils have a large dose of sulphur in them that will eat up the syncro's. It might also cause the symptoms you're seeing. Given the incompetence shown by the shop already it wouldn't surprise me at all if they put the wrong oil in. What should be in there is GL4 oil. Ask your friend what oil his Porsche dealership uses when they change transmission oil, and you might want to consider a DIY on changing it.
Hi Kevin, good to have an authoritative voice speaking up...Do not use ATF in your transmission, unless you want to hasten its demise! Use a quality 75W90 manual transmission fluid such as Mobil 1 LS 75W90, Motul 300 75W90, or Porsche or Audi's branded fluid.
Another possible cause for your clutch to drag is air in the clutch hydraulics. A positive-pressure bleed would help purge air from the system. Could be a bad master or slave cylinder as well. Good luck,
I'm not a lubrication scientist or engineer and so cannot give a very deep answer. Different viscosity, different base chemistry, additives, etc. Yes, some manual transmissions have been designed for ATF: I owned a Mercedes 190E2.3-16 that used ATF in its manual transmission. They key notion here is that they were designed for ATF.What's the issue with ATF in a manual transmission? I seem to recall some manual transmissions actually called for ATF. It would seem the needs of the two would be very similar. Gear and bearing lubrication. In the automatic - the fluid has to work with the friction clutches, in the manual, it would have to work with the synchronizer rings. What issues have you seen? My experience with it in the 1983 Toyota Supra was it solved a lubrication problem, where I got an awful-sounding squeal with a cold transmission on the 1st-2nd gear shift. My mechanic thought that it might be the transmission fluid drained down off a component - and using ATF the lanolin in it stayed in place better. Whatever - it was quiet and smooth shifting for the rest of the time I owned it.
No - I don't think that's a good analogy really. The analogy would be closer if the runner sprained his ankle, and was given the choice of finishing the race with aspirin or finishing the race without aspirin and with the ankle still causing pain, or being shot right there (as one does with horses..)If you use a different type of fluid, or a heavier grade (eg, 75W140) and it appears to "solve" the problem, chances are that it's just hidden the problem at the expensive of accelerated wear and damage to parts of the transmission that were designed and tested for the original fluid. If you were running a marathon, and you sprained your ankle at mile 10, would you pop a few pain killers and finish the race? I hope not. But it is a fair analogy to what is likely happening with a variant fluid in a transmission that shows issues with the designed-for fluid. Cheers,
The plot thickens, I looked through the records of the shop and they are not using oem fluids and I have no idea if they used an oe shifter cable revision, slave or what.Two things I’m getting out of this discussion: I agree with ‘schwinn’ here about checking the clutch/pressure plate, maybe even a warped or deformed flywheel. And secondly, I would NOT bring my car back to this mechanic. I wouldn’t trust him to put air in my tires.
.Good find. I don't think non-OEM is necessarily bad, but whatever it is should match the required specs... so it would be good to check. If it doesn't match, then that's a good lead on the matter. If the specs match (GL rating as well as anti-slip additives and weights), then it may not be the issue, and you could skip that step/cost. Of course, you could change it anyway if you really wanted to... but I'm of the belief that if the specs match then you should be fine.
Of course, a fluid change would be cheaper than the clutch work, but I really feel that's where the issue lies...
Both shops worked the cables, the 1st shop who installed them 10k mi ago, never adjusted them properly.Welp, at least someone finally seems to have solved it. I figured you'd find something like that.
When the clutch pedal is down, the engine should be physically disconnected from the transmission. So if the clutch is working right there's absolutely no way for anything aft of the clutch (transmission, shifter assembly, shift cables, fluid, gears, synchros, whatever) to cause the car to creep with the clutch pedal down. Any competent mechanic should have understood that right off the bat, and honestly it's pretty disturbing that their first thought after verifying that symptom was "let's check the shift cables".
Is this the same shop as before? Because if what you're saying about their troubleshooting capabilities is accurate then you really need to find another shop. I'm purely shade-tree but apparently I'm a lot better than your guys!
Anyway, once isolated to the clutch then it's got to be either the hydraulic release mechanism or, failing that, the clutch assembly is f-ed in some way.
Okay, that's better, I thought you were still at the first place, lol. As long as he didn't try to blame the latter on the former you're all right.The current mechanic told me that he knew there were 2 issues, one being the disengagement issues and second, something wrong with the cables.
No blame games, it difficult to pin point how the disengagement issues started but it's pretty obvious the first shop who installed the cables are incompetent. When the first shop installed the cables, I had to go back because I was having issues with shifting. I had to go for a ride with them and show them what it was doing. They adjusted something and it seemed better.Okay, that's better, I thought you were still at the first place, lol. As long as he didn't try to blame the latter on the former you're all right.
I would think the starting without a clutch issue is the switch.I had an incident this morning that made me think of this thread. I am in the process of doing a brake job (pads & rotors followed by flush) on my 2010 Cayman 2.9L MT. The car is up on Quick Jack with wheels off. I just finished the last (left rear) wheel and wanted to test that the new wear sensors were all working, so I started the car and stepped out. It was in neutral. I noticed the left rear rear hub/rotor as slowly spinning. That's what reminded me of this thread. The right rear was stationary. After double checking it was in neutral, I put a gloved hand on the rotor and easily stopped it. When I let go, it remain stationary, but with a slight nudge, it started again. Is this normal?
Oh, one other odd thing associated with the above. I was able to start the engine without getting in and pressing the clutch or brake. I assumed my clutch switch is faulty and don't think it is related to the rotation.