What's that sound? Slapping noise with clutch depressed
05-27-2018, 03:16 PM
#1
Three Wheelin'
Thread Starter
What's that sound? Slapping noise with clutch depressed
I was installing the eibach pro kit springs on my 997.1 C4 last week and when I had the car up on jackstands, I decided to fire it up for kicks. I had recently installed what I like to call the super gundo exhaust, which has the PSE and inlet/outlet pipes both welded in. It sounds great! You can hear it in the beginning of the video.
Interestingly, I found that when I pressed the clutch in, I heard a slapping/tapping noise. It's best heard once the idle settles in at about 1:30 mark. The noise is only heard when the clutch pedal is depressed. When I let off the clutch it goes away. Notably, I had my transmission replaced about 500 miles ago due to worn synchros and a bad bearing (attributed to prior owner, perhaps). When the shop that did the work inspected the clutch, they said it was nearly brand new with about 75-80% meat left on it and the flywheel looked new as well, so they did not recommend replacing.
What do y'all think this is?
Interestingly, I found that when I pressed the clutch in, I heard a slapping/tapping noise. It's best heard once the idle settles in at about 1:30 mark. The noise is only heard when the clutch pedal is depressed. When I let off the clutch it goes away. Notably, I had my transmission replaced about 500 miles ago due to worn synchros and a bad bearing (attributed to prior owner, perhaps). When the shop that did the work inspected the clutch, they said it was nearly brand new with about 75-80% meat left on it and the flywheel looked new as well, so they did not recommend replacing.
What do y'all think this is?
05-30-2018, 07:59 PM
#2
Three Wheelin'
Thread Starter
Bumping this up. Noise seems to go away when engine is warm. Weird...
05-31-2018, 10:45 AM
#3
Three Wheelin'
No idea on that one but seems likely related to the flywheel. Hopefully some others have more educated opinions.
Let us know what your indy thinks.
Ps - what was the symptoms of the worn synchros? Have never heard that before on a 997.
Let us know what your indy thinks.
Ps - what was the symptoms of the worn synchros? Have never heard that before on a 997.
05-31-2018, 11:46 AM
#4
Three Wheelin'
Thread Starter
I did not notice any symptoms for the worn synchros. In fact, when I took the car in to get the left side of the engine resealed (I had a weaping cam case cover), I asked about replacing the clutch since the engine was going to be dropped anyway. My indy put the car on the lift and noticed the transmission was shaking at idle. They felt it was a bad bearing shaft and I gave them the go ahead to investigate further. When they removed the gear fluid it was filled with metal particles. In retrospect, I did have significant shaking of the front seats especially at idle that went away almost completed with the new trans.
Re: the tapping - I believe it might be flywheel related vs throwout bearing.
Re: the tapping - I believe it might be flywheel related vs throwout bearing.
06-01-2018, 04:10 PM
#5
Rennlist Member
interesting...i think i have the same thing. altho mine is sometimes noticeable when clutch is out but def more so when clutch in. just to make sure i am hearing it correctly, it's almost like an intermittent, random "ticking", right? and it's not necessarily dependent on RPM (as would be valve issue, etc)?
06-01-2018, 04:34 PM
#6
Three Wheelin'
Thread Starter
interesting...i think i have the same thing. altho mine is sometimes noticeable when clutch is out but def more so when clutch in. just to make sure i am hearing it correctly, it's almost like an intermittent, random "ticking", right? and it's not necessarily dependent on RPM (as would be valve issue, etc)?
i didn’t have the stones to rev the car on jack stands but I will test it in neutral in my garage as soon as I get a chance to see if it’s RPM dependent
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06-05-2018, 11:25 PM
#8
Three Wheelin'
Thread Starter
Not yet - just got back from traveling. Hopefully will get a chance to take in soon (again).
07-08-2018, 05:19 PM
#9
Three Wheelin'
Thread Starter
Welp, turned out to be much ado about nothing. I didn't tighten the exhaust bracket bolts well enough when I installed my super Gundo mufflers and I guess with the clutch disengaged, they were chattering. Tightened it up and all good now; no more noise!
This car is so much fun to drive with a brand new trans - buttery smooth and simply sublime. No issues going into first and even 1-2 is relatively smooth.
This car is so much fun to drive with a brand new trans - buttery smooth and simply sublime. No issues going into first and even 1-2 is relatively smooth.