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Clunk when driving off from a stop

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Old 08-14-2010, 08:35 PM
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PasPar2
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Default Clunk when driving off from a stop

2002 c2 tip 87k miles.

This started happening after my DE of last week. When I apply the gas from a full stop - the car starts rolling and I get a one time clunk from the rear. Only happens when I gas it a bit not when I just roll off like grandma...

shop is closed and I wont be able to make it till next weekend - any ideas before I get it looked it (sort of **** about things being wrong with the car)

thanks
Old 08-16-2010, 01:29 PM
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jcan
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I'm trying to track down a similar problem. When I got under the car I noticed that the transmission bracket which attaches to the car has two bolts/studs and the bracket had shifted back and forth leaving a shiny wear spot. I loosened it/ aligned it( let it go back to where it wanted) and tightened it up. I haven't had the metallic clunk anymore, just a softer one. I'm going to pick up some engine mounts and see if that helps.
Old 08-16-2010, 01:55 PM
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Dervish
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Check your nuts! I know this sounds weird but I had the exact same sound, almost like a rock in the engine bay. Only happened when pulling forward or in reverse. Turned out I had 2 nuts missing from 1 rear and all other nuts were loose!! Result of a (very) bad wheel refurb and then a DE. Heat cycle had melted the paint that was (wrongly) in the bolt holes, the nuts had worked loose on drive home...

It's probably something else but check them nuts...
Old 08-16-2010, 10:09 PM
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Pac996
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Sounds like motor mounts. Not sure if you have had a life of busting motor mounts but if it sounds like that big chunk of engine bumping up against a solid body or frame of the car then check your motor mounts. Look for oil leaked near mounts or off balanced exhaust tips. What ever the case have fun.
Old 08-17-2010, 01:47 AM
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htny
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trans mounts, pain in the ***, i've had mine done twice under warranty
Old 08-17-2010, 09:30 AM
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PasPar2
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thanks all. Its bugging me so I will try to leave early and make it to the shop. I am cutting it close to my next DE so this needs to get done asap.

I read up on the trans mount and seems that the only way to know if its bad is to remove it and inspect it but its holding on via 4 bolts so its not a biggie. My exhaust tips were always abit off - I had fabspeeds and now I have fister Ds and I could never get them to align properly - but I never had vibration before which is indicative of bad motor mounts. This thump is something new and from reading up is more likley to be the trans mount...

Ill update this when I get it looked at

thanks
Old 08-17-2010, 07:41 PM
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PasPar2
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tranny mount.... got the updated 997 part on order from pelican
Old 08-17-2010, 08:02 PM
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Tippy
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Originally Posted by htny
trans mounts, pain in the ***, i've had mine done twice under warranty
Yep. They are known ti fail at low miles. Never replaced mine. It stopping clunking after awhile so I never changed it.
Old 08-17-2010, 09:47 PM
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Barn996
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Originally Posted by PasPar2
tranny mount.... got the updated 997 part on order from pelican

Nice to know you found the problem.
Old 08-17-2010, 10:04 PM
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cannon1000
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Transmission mount for sure. Here is a piece of advice from the shop that fixed mine. Don't replace the bushing (they may inspect and say you have one broken) get the whole mount replaced. Here's why.

Bushing only is 3 hours labor (per bushing). If they find both need replacing...that is a lot of $ for a cheap part and lots of labor.

Entire Mount - includes new bushings: $228 (part) + 2 hours labor.
My "Porsche Only" repair shop did the whole thing for $178 Labor + 228 Parts.

Get this fixed as it does cause the transmission to twist...and it can cause stress on other mounts and the engine.
Old 08-18-2010, 12:27 AM
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jcan
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Originally Posted by PasPar2
tranny mount.... got the updated 997 part on order from pelican
Which part # is that from Pelican as I've got a suspect transmission mount on mine...
As you know to change just the mount is a MAJOR deal in getting a press and popping the old one out, not to mention removal of the transmission. If I can just replace the whole tranny mount with an updated 997 part number.... This is sounding good.
Old 08-18-2010, 03:19 AM
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Pac996
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"A clunk when driving off from a stop" That's your beer can on the roof falling off.
Old 08-18-2010, 04:24 AM
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cannon1000
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Feel free to call Matt @ Motorwerks Racing in Cumming, GA. He replaced mine...perhaps he can give you some advice.
Old 08-18-2010, 09:44 AM
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PasPar2
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Originally Posted by jcan
Which part # is that from Pelican as I've got a suspect transmission mount on mine...
As you know to change just the mount is a MAJOR deal in getting a press and popping the old one out, not to mention removal of the transmission. If I can just replace the whole tranny mount with an updated 997 part number.... This is sounding good.
not on a tip... 1 mount + 4 bolts + 30 minutes
Old 08-18-2010, 01:15 PM
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Dervish
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Originally Posted by PasPar2
not on a tip... 1 mount + 4 bolts + 30 minutes
Think you can follow this for DIY... http://www.renntrack.com/forums/show...t=transmission

?


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