CRAP! New Clutch/Flywheel?
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 866
Likes: 0
From: Madison Wisconsin
CRAP! New Clutch/Flywheel?
Ok guys,
There is a weird rattling noise coming from where the tranny is. I originally thought it was just an exhaust rattle, but I asked the guys at jiffy lube if I could take a look under my car. It doesn't look like an exhaust rattle at all! It sounds like it's coming from the tranny. The guys there told me it's probably my clutch and/or flywheel. The noise occurs when the engine revs at about 1.5k and come back down. I'll probably take it to a transmission shop sometime soon.
Question about the clutch. Is it normal for the clutch to feel extremely weird when the car revs up to 5+ k? The clutch changes its gripping point and take a while to change back to the way I'm accustomed to driving it.
Vince
There is a weird rattling noise coming from where the tranny is. I originally thought it was just an exhaust rattle, but I asked the guys at jiffy lube if I could take a look under my car. It doesn't look like an exhaust rattle at all! It sounds like it's coming from the tranny. The guys there told me it's probably my clutch and/or flywheel. The noise occurs when the engine revs at about 1.5k and come back down. I'll probably take it to a transmission shop sometime soon.
Question about the clutch. Is it normal for the clutch to feel extremely weird when the car revs up to 5+ k? The clutch changes its gripping point and take a while to change back to the way I'm accustomed to driving it.
Vince
Instructor
Joined: Dec 2006
Posts: 134
Likes: 0
From: Charlotte North Carolina
My son (2001 Z06 466+ rwhp)just boogered a new clutch 
and had disregarded the subtle changes he noticed before loosing the whole kaboodle 
at the track. IMO Have the clutch looked at before you end up buying a whole new set-up! Good luck!
and had disregarded the subtle changes he noticed before loosing the whole kaboodle at the track. IMO Have the clutch looked at before you end up buying a whole new set-up! Good luck!
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Does the rattling happen with the clutch engaged (in neutral), or just with your foot in it. It may be the throwout bearing. Also the clutch engagement height sounds like it could possibly be the sticking clutch issue many C5's have. Do a search on sticking clutch.
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 866
Likes: 0
From: Madison Wisconsin
Alright. Will do. The sound happens in any gear. W/ or W/O the clutch engaged the sound occurs. Does this mean it is probably the fly wheel? I wouldn't see how it could be the tranny considering the sound comes regardless of if I am moving or not.
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
It still could be the throwout bearing. It's mounted right at the end of the crankshaft. If the bearing is shot it wil make a rattling sound. The sound I was refering to is the 'marbles in a can' sound. If it sounds like that it could be your throwout bearing. I doubt it is the flywheel, no moving parts there. A bolt could be loose on the pressure plate though. That would be the easiest fix, as you can get to them by removing the inspection cover. A throwout bearing requires pulling the propeller shaft back and removing the pressure plate.
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Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
First step I'd suggest is doing some rigorous maintenance of your clutch fluid. Taking Care of Your Clutch
I'll predict that the clutch fluid in your is serious black and gooey and is boiling when you hammer the car.
The sound you're hearing at 1500 rpm can be many things that are not related to the clutch. First thing I'd look at would be the exhaust runs from the collector to the rear of the car, checking for loose connections and clearance between the components and the under-carriage of the car.
Good luck and let us know what you find.
Ranger
I'll predict that the clutch fluid in your is serious black and gooey and is boiling when you hammer the car.
The sound you're hearing at 1500 rpm can be many things that are not related to the clutch. First thing I'd look at would be the exhaust runs from the collector to the rear of the car, checking for loose connections and clearance between the components and the under-carriage of the car.
Good luck and let us know what you find.
Ranger
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
^^^ I'd suggest you do the checking of the fluid yourself and then follow the procedure I wrote up.
On the other hand, if cost is not a concern, prepare for bleeding the clutch three or four times at $125 per. Also prepare for a botched bleed, because shops hate doing the procedure. They'd rather sell you a clutch plus install. Many of those are unnecessary.
Ranger
On the other hand, if cost is not a concern, prepare for bleeding the clutch three or four times at $125 per. Also prepare for a botched bleed, because shops hate doing the procedure. They'd rather sell you a clutch plus install. Many of those are unnecessary.
Ranger
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 866
Likes: 0
From: Madison Wisconsin
Hmm... Well I went to a transmission shop.... They never put it on a lift but they sounded confident that it was just an exhaust rattle. I'm changing out my exhaust with some SLP's this weekend and we'll see if that fixes anything. If not... 
Burning Brakes
Joined: Aug 2004
Posts: 770
Likes: 0
You have two different and seperate problems.
1) The rattle at 1500 rpm
Does it make the noise only as you let off and the rpms drop?
If so, one of the cats has a broken ceramic element.
The broken element gets forced downstream as rpm and exhaust flow rises and then becomes loose and rattles when you let off and rpms drop.
Replace the cat with the broken element.
2) Clutch engagement point changes after shifting at 5k plus rpm
I agree with Ranger - But if you added a remote bleeder when you put in the new clutch, bleed the system thru the remote bleeder. If you don't have a remote bleeder - just r & r the clutch master cyl. fluid. Change the fluid, drive a few days, change it again, repeat until the fluid stays clear and the problem is resolved.
1) The rattle at 1500 rpm
Does it make the noise only as you let off and the rpms drop?
If so, one of the cats has a broken ceramic element.
The broken element gets forced downstream as rpm and exhaust flow rises and then becomes loose and rattles when you let off and rpms drop.
Replace the cat with the broken element.
2) Clutch engagement point changes after shifting at 5k plus rpm
I agree with Ranger - But if you added a remote bleeder when you put in the new clutch, bleed the system thru the remote bleeder. If you don't have a remote bleeder - just r & r the clutch master cyl. fluid. Change the fluid, drive a few days, change it again, repeat until the fluid stays clear and the problem is resolved.
Racer
Joined: Nov 2006
Posts: 436
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From: Chatham Ontario
Burning Brakes
Joined: May 2003
Posts: 850
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From: Green Lane Pennsylvania
Thread Starter
Burning Brakes
Joined: Aug 2007
Posts: 866
Likes: 0
From: Madison Wisconsin
. I was scrambling to find a jack and got pissed... Got some taco bell... and took my car next door and asked to see if I could take a look.... They just came downstairs w/ me 
.
1st Gear
Joined: Jan 2008
Posts: 1
Likes: 0
Noise at 1500RPM at aceleration only
I have 99 Vette w/automatic transmission with this similar rattling or buzzing noise at 1500RPM at aceleration only.
I have replaced the exhaust and cats. The harmonic balancer has been replaced too. The noise is still present. There is no loss in power. I have had my Vette performance guy check everything and he cannot find it. Any other ideas?
Thanks
I have replaced the exhaust and cats. The harmonic balancer has been replaced too. The noise is still present. There is no loss in power. I have had my Vette performance guy check everything and he cannot find it. Any other ideas?
Thanks
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Theres TWO things that I recommend doing:
1. Jack the car and use a rubber mallet and bang on the CATs and see if they rattle on the inside. If they do,, the brick inside id damaged. Then work your way down the exhaust system and listen for rattles. If the brick is damaged in the cats, the crap will collect in the muffler and make noise there too.
2. Theres a removable plate on the bottom of the bell housing. Remove that cover and see if you see anything out of the ordinary.
Bill
1. Jack the car and use a rubber mallet and bang on the CATs and see if they rattle on the inside. If they do,, the brick inside id damaged. Then work your way down the exhaust system and listen for rattles. If the brick is damaged in the cats, the crap will collect in the muffler and make noise there too.
2. Theres a removable plate on the bottom of the bell housing. Remove that cover and see if you see anything out of the ordinary.
Bill
Last edited by Bill Curlee; Jan 26, 2008 at 08:32 AM.