997.1 Trans or clutch or slave cylinder noise? Maybe exhaust?
11-16-2018, 08:25 PM
#1
Three Wheelin'
Thread Starter
997.1 Trans or clutch or slave cylinder noise? Maybe exhaust?
Ok folks. Here's the scene: one of the annual 10 nice days of the year in Houston. I take my 997 to work (a rarity). Driving home, decide to do it with the windows down (it's really nice outside, after all!). Radio is off, climate control is off. Just me and the car. Shift from stop to 1st a couple times and I hear a weird "scrape" type noise only after my foot is off the clutch and car is engaged in first gear. I thought it was a car next to me at first, but it's definitely mine. It does not happen at all (to my knowledge) in the other gears, only after engaging first.
There are no other symptoms. The clutch grab feels totally normal, there is no vibration, and if I don't have the windows down, I cannot hear it - certainly cannot hear it with windows up, radio on, climate control on.
So I took it out again after I got home and made some videos. It's mostly intermittent but it happens more often than not. It happens after my foot is completely off the clutch. You can hear it for the first time 2 seconds into the video and it does not happen each time - it happens on the first 3 rolls, you can barely hear it on the 5th, and then you can hear it on the second to last roll. Can anyone diagnose the noise? Trans/clutch/exhaust/cats? The transmission is maybe 1.5k miles old, brand new Porsche box. The clutch was in perfect condition so I wasn't recommended to replace it, and I was also told the flywheel was in excellent shape.
There are no other symptoms. The clutch grab feels totally normal, there is no vibration, and if I don't have the windows down, I cannot hear it - certainly cannot hear it with windows up, radio on, climate control on.
So I took it out again after I got home and made some videos. It's mostly intermittent but it happens more often than not. It happens after my foot is completely off the clutch. You can hear it for the first time 2 seconds into the video and it does not happen each time - it happens on the first 3 rolls, you can barely hear it on the 5th, and then you can hear it on the second to last roll. Can anyone diagnose the noise? Trans/clutch/exhaust/cats? The transmission is maybe 1.5k miles old, brand new Porsche box. The clutch was in perfect condition so I wasn't recommended to replace it, and I was also told the flywheel was in excellent shape.
11-17-2018, 01:21 AM
#2
Three Wheelin'
Thread Starter
Did some more empirical data gathering on a shakedown run tonight.
The sound is resonant, likes to occur when decelerating in gear through ~2500 RPM and ~1250 RPM in any gear. I can make it occur by driving in second gear past 2500 RPM and then engine braking. So I think it's a loose bracket bolt somewhere. Hopefully nothing more than that!
The sound is resonant, likes to occur when decelerating in gear through ~2500 RPM and ~1250 RPM in any gear. I can make it occur by driving in second gear past 2500 RPM and then engine braking. So I think it's a loose bracket bolt somewhere. Hopefully nothing more than that!
11-17-2018, 10:24 AM
#3
RL Community Team
Rennlist Member
Rennlist Member
Isn't there a helper spring on the clutch pedal to help it come back up. Sounds like the spring popping as you let out the clutch. Check the little button switch that's installed on on the clutch pedal too. This is fun as you have to lower the front of the seat all the way down, recline the back a little then flip yourself upside down so you can put your head under there laying on your shoulder blades to really see what's going on under there
.... or I guess you could use a scope camera, but the first way is more engaging.
.... or I guess you could use a scope camera, but the first way is more engaging.
11-17-2018, 02:05 PM
#4
Three Wheelin'
Thread Starter
As most things, this one was mea culpa. Turns out I never bolted up the dual tip on the passenger side. At least it's a cheap fix!
