996 Engine Vibration-Seats Shake at Idle
12-03-2002, 10:41 PM
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996 Engine Vibration-Seats Shake at Idle
My 99 996 Coupe has been at a N. Cal dealer since 11/13/02 with a mysterious engine vibration. The symptoms (seats shake, humming noise) aren't affected by clutch being in or out, nor does the AC on or off make much of a difference. Dealership
said a replacement engine would be provided, however I was informed today (12/3) that Porsche
Tech Assistance (Atlanta) wanted to have the engine opened up at the dealership for "more analysis". Dealership says no definite date given
for final action. Have any other 99 996 owners
have this problem ? Any solutions ? Advice ?
said a replacement engine would be provided, however I was informed today (12/3) that Porsche
Tech Assistance (Atlanta) wanted to have the engine opened up at the dealership for "more analysis". Dealership says no definite date given
for final action. Have any other 99 996 owners
have this problem ? Any solutions ? Advice ?
12-04-2002, 12:28 AM
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YES! I just purchased my '99 C4 five days ago and mine has the EXACT same problem!!! I just purchased a bottle of Chevron Techron fuel system cleaner tonight hoping it might just be something of that nature, but now maybe I should have it looked at anyway! As you said, it's completely independant of the cluth being in or out, AC compressor (it's only 13 degrees here in Canton, OH right now so I'm certainly not using it! <img src="graemlins/crying.gif" border="0" alt="[crying]" /> ), etc... Feels "sort of" like the vibration you get when a car is ready to stall or something sometimes. I will be very interested to know what you find out!
And sorry everybody for not posting to let you know I've finally purchased my new baby but I've been too busy driving!!! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" /> BUT, you'll be happy to know I became a real Rennlist Member yesterday so I hope that makes up for it! The car is an Arctic Silver '99 C4 with black leather seats front and rear, comfort seats with full power/lumbar, litronic lights, hi-fi sound, onboard computer, rear wiper, carbon shift ****/handbrake and the standard 17" C4 wheels. And I'm in love!!! Much nicer to "me" than my 964-series C4 I sold a year ago!
And sorry everybody for not posting to let you know I've finally purchased my new baby but I've been too busy driving!!! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" /> BUT, you'll be happy to know I became a real Rennlist Member yesterday so I hope that makes up for it! The car is an Arctic Silver '99 C4 with black leather seats front and rear, comfort seats with full power/lumbar, litronic lights, hi-fi sound, onboard computer, rear wiper, carbon shift ****/handbrake and the standard 17" C4 wheels. And I'm in love!!! Much nicer to "me" than my 964-series C4 I sold a year ago!
12-04-2002, 01:26 AM
#4
Drifting
There is at least one TSB that talks about vibration. Here is part of that TSB (10/99 1379):
Vehicle Type: 911 Carrera (996), 911 Carrera 4 (996)
Model Year: As of 1999 (X)
Concern: Torn or damaged drive belt
Information: Certain driving conditions (very low engine RPMs with high engine load) can bring about engine
vibrations/oscillations that may cause the engine drive belt to derail from the crankshaft pulley. Should
this occur, the lip of the crankshaft pulley can damage the engine drive belt....
The fix is to replace the belt and guide.
996 102 235 01 New/drive belt guide clip
996 102 151 64 Polyrib drive belt (M573)
Vehicle Type: 911 Carrera (996), 911 Carrera 4 (996)
Model Year: As of 1999 (X)
Concern: Torn or damaged drive belt
Information: Certain driving conditions (very low engine RPMs with high engine load) can bring about engine
vibrations/oscillations that may cause the engine drive belt to derail from the crankshaft pulley. Should
this occur, the lip of the crankshaft pulley can damage the engine drive belt....
The fix is to replace the belt and guide.
996 102 235 01 New/drive belt guide clip
996 102 151 64 Polyrib drive belt (M573)
12-05-2002, 12:04 AM
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I have an '02 996 C2. I do notice a very, very
slight vibration of the seats. I chalk it up
to the stiff chasis of such a sports car where
you're going to feel every bump from the road
and engine rumble.
I want to hear from others that this very slight
vibration happens with their cars as well--that
this is pretty normal... How about it guys?
slight vibration of the seats. I chalk it up
to the stiff chasis of such a sports car where
you're going to feel every bump from the road
and engine rumble.
I want to hear from others that this very slight
vibration happens with their cars as well--that
this is pretty normal... How about it guys?
12-05-2002, 12:34 AM
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rushing23,
This vibration we're referring to does not occur while driving (or at least mine doesn't), only when sitting at idle, and it is definately not normal sports car engine rumble, I'm talking about a bad vibration almost like when a car is just ready to stall that shakes everything, even the mirrors. If I tap on the gas it immediately goes away but it returns again right after the engine falls back to idle speed. AveryII, is this what yours does as well?
This vibration we're referring to does not occur while driving (or at least mine doesn't), only when sitting at idle, and it is definately not normal sports car engine rumble, I'm talking about a bad vibration almost like when a car is just ready to stall that shakes everything, even the mirrors. If I tap on the gas it immediately goes away but it returns again right after the engine falls back to idle speed. AveryII, is this what yours does as well?
12-05-2002, 02:28 AM
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Marc: Yes, the symptoms and patterns of your engine vibration on your 99 996 C2 are identical to mine. You may want to check your warranty for
an expiration date and (then) go to a nearby dealer to have this problem assessed. Please let me know if I can be of further assistance.
Avery
an expiration date and (then) go to a nearby dealer to have this problem assessed. Please let me know if I can be of further assistance.
Avery
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12-05-2002, 11:21 AM
#8
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I have a 2001 and the tach at idle never really sits still. It continues to oscillate between 750 - 800 rpms w/o any load and w/o being in any gear. It is annoying but certainly nothing like the sensation that the engine is about to stall. I took mine to have it checked out and the dealer said that it's a Porsche, it's engine is not going to be the smoothest in the world. 
12-05-2002, 05:04 PM
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[quote]it's a Porsche, it's engine is not going to be the smoothest in the world.<hr></blockquote>
My car exhibits the same behavior as urs
Chicago996, but I just tell myself it's the Fabspeed exhaust.
When I drove a boxster loaner, the engine in that car was perfectly rock solid when idling. The needle didn't move at all, and there was no vibration to be felt.
And I also remember reading that the flat 6 and inline 6 configurations have the least vibration of all, so I kinda doubt what your dealer said. Think a stock 996 should be as vibration-free as the boxster.
My car exhibits the same behavior as urs
Chicago996, but I just tell myself it's the Fabspeed exhaust.
When I drove a boxster loaner, the engine in that car was perfectly rock solid when idling. The needle didn't move at all, and there was no vibration to be felt.
And I also remember reading that the flat 6 and inline 6 configurations have the least vibration of all, so I kinda doubt what your dealer said. Think a stock 996 should be as vibration-free as the boxster.
12-05-2002, 06:04 PM
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I too have driver both Boxster and Boxster S and neither felt that vibration nor saw the tach needle fidgeting. But the $65K question is what can we do about it as it is more of a nuisance than anything else (I hope and per the dealer)?
05-08-2024, 08:24 PM
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