Strange Engine Sound
10-05-2011, 06:01 PM
#16
Drifting
Thread Starter
I agree, great idea! I assume that's how they make money anyway by putting in a warranty claim to Porsche. I'm optimistic they will do something and hopefully won't say they all do that...
10-06-2011, 09:58 AM
#17
Rennlist Member
Erm sorry to say this but.... erm...
.....most of them do that.
See, I didnt say all...
Here is a relevant post, which talks about this issue in detail. And from your original description, I think it is exactly the same sound.
POST ON 997 TURBO NOISE
.....most of them do that.
See, I didnt say all...
Here is a relevant post, which talks about this issue in detail. And from your original description, I think it is exactly the same sound.
POST ON 997 TURBO NOISE
10-06-2011, 10:35 AM
#18
Drifting
Thread Starter
Erm sorry to say this but.... erm...
.....most of them do that.
See, I didnt say all...
Here is a relevant post, which talks about this issue in detail. And from your original description, I think it is exactly the same sound.
POST ON 997 TURBO NOISE
.....most of them do that.
See, I didnt say all...
Here is a relevant post, which talks about this issue in detail. And from your original description, I think it is exactly the same sound.
POST ON 997 TURBO NOISE
10-07-2011, 11:50 AM
#19
Intermediate
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If it sounds something like this:
It's normal. That's your intermediate shaft. 996tt and 997tt have this sound, some worse than others. From my research it's a result of tolerance stack up. Backlash between the gear interface of the crank shaft and the intermediate shaft. Some gears are just matched up better than others. The guy in the video was freaked out about the noise so he tore down his engine to see inside. There was some minor wear on his IMS bearing but nothing out of the ordinary. He replaced all the slightly worn components and the engine noise disappeared only to come back a few thousand miles later.
Personally I think it's kind of pathetic for an engine of this caliber to make this noise. Makes it sound like a cheap VW. The noise only manifests itself once the engine is warm and disappears after about 1800 RPM. You shouldn't hear it on a cold start. At least these things sound beautiful at WOT
It's normal. That's your intermediate shaft. 996tt and 997tt have this sound, some worse than others. From my research it's a result of tolerance stack up. Backlash between the gear interface of the crank shaft and the intermediate shaft. Some gears are just matched up better than others. The guy in the video was freaked out about the noise so he tore down his engine to see inside. There was some minor wear on his IMS bearing but nothing out of the ordinary. He replaced all the slightly worn components and the engine noise disappeared only to come back a few thousand miles later.
Personally I think it's kind of pathetic for an engine of this caliber to make this noise. Makes it sound like a cheap VW. The noise only manifests itself once the engine is warm and disappears after about 1800 RPM. You shouldn't hear it on a cold start. At least these things sound beautiful at WOT
10-08-2011, 11:16 AM
#20
Race Director
It is the engine's caliber, its performance, that this noise comes from. That is the gear drive from the crank to the IMS is a very efficient drive system and reliable (no chain tensioners/guides).
Just to back up a bit these are high performance engines and the designers have pulled out quite a few stops to gain/extract this performance. And I think the consenous is they've done this rather well.
The trade off is the engine is a bit more raw, read noisier, than other engines.
There are ways to cut down on the noise but these ways -- chain or rubber belt drives -- bring with them their on set of problems. Chain drive I believe takes a bit more hp while a rubber drive belt requires periodic replacement.
When I get into a luxury sedan I expect quiet. When I get in my Turbo I expect the car to be a bit more raw, visceral and thus not as quiet. But oh my any issue with the noise is gone when the hammer gets dropped! Yeee Haw!
Sincerely,
Macster.
Just to back up a bit these are high performance engines and the designers have pulled out quite a few stops to gain/extract this performance. And I think the consenous is they've done this rather well.
The trade off is the engine is a bit more raw, read noisier, than other engines.
There are ways to cut down on the noise but these ways -- chain or rubber belt drives -- bring with them their on set of problems. Chain drive I believe takes a bit more hp while a rubber drive belt requires periodic replacement.
When I get into a luxury sedan I expect quiet. When I get in my Turbo I expect the car to be a bit more raw, visceral and thus not as quiet. But oh my any issue with the noise is gone when the hammer gets dropped! Yeee Haw!
Sincerely,
Macster.
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Robocop305 (12-24-2021)
10-11-2011, 12:57 PM
#21
Drifting
Thread Starter
Visited the dealer this morning. The mechanic came over and told me the car is perfect and the noise is normal in all 996 and 997 Turbo's. He also told me he's been a Porsche mechanic for 25 years and he's certain of his findings. I have no reason not to believe him and at least it's documented should I have an issue in the future. The car runs great so I'm not going to worry about it. Thanks for feedback everyone.
10-11-2011, 02:18 PM
#22
10-12-2011, 12:35 PM
#23
Race Director
It is the engine's caliber, its performance, that this noise comes from. That is the gear drive from the crank to the IMS is a very efficient drive system and reliable (no chain tensioners/guides).
Just to back up a bit these are high performance engines and the designers have pulled out quite a few stops to gain/extract this performance. And I think the consenous is they've done this rather well.
The trade off is the engine is a bit more raw, read noisier, than other engines.
There are ways to cut down on the noise but these ways -- chain or rubber belt drives -- bring with them their on set of problems. Chain drive I believe takes a bit more hp while a rubber drive belt requires periodic replacement.
When I get into a luxury sedan I expect quiet. When I get in my Turbo I expect the car to be a bit more raw, visceral and thus not as quiet. But oh my any issue with the noise is gone when the hammer gets dropped! Yeee Haw!
Sincerely,
Macster.
Just to back up a bit these are high performance engines and the designers have pulled out quite a few stops to gain/extract this performance. And I think the consenous is they've done this rather well.
The trade off is the engine is a bit more raw, read noisier, than other engines.
There are ways to cut down on the noise but these ways -- chain or rubber belt drives -- bring with them their on set of problems. Chain drive I believe takes a bit more hp while a rubber drive belt requires periodic replacement.
When I get into a luxury sedan I expect quiet. When I get in my Turbo I expect the car to be a bit more raw, visceral and thus not as quiet. But oh my any issue with the noise is gone when the hammer gets dropped! Yeee Haw!
Sincerely,
Macster.
yes, there always be a little gear noise from the crank to IMS gears. I don't think anybody is going to cry about that. The fact that you bring up chain drives is irrelevant given that thousands of engines, including those in high end luxury sedans, use chains.
The air cooled mezger motors are naturally louder because they have no material between the cylinders to dampen the noise. But my 993TT doesn't have this rattle, and not all 996TT/997TT, GT3, GT2 or other mezger motors have this rattle.
Yes, there will be some tolerance stack, but given that these are flagship cars from a company known for this engineering prowess, this should not occur. If my brand new $130k 911 turbo sounded like a VW bus with a bad rod bearing, I'd be pissed.
Bob, I'd be interested in listening to this thing. While this may not be indicative of a dangerous problem, it would sure **** me off.
10-12-2011, 12:44 PM
#24
Drifting
Thread Starter
sorry, no.
yes, there always be a little gear noise from the crank to IMS gears. I don't think anybody is going to cry about that. The fact that you bring up chain drives is irrelevant given that thousands of engines, including those in high end luxury sedans, use chains.
The air cooled mezger motors are naturally louder because they have no material between the cylinders to dampen the noise. But my 993TT doesn't have this rattle, and not all 996TT/997TT, GT3, GT2 or other mezger motors have this rattle.
Yes, there will be some tolerance stack, but given that these are flagship cars from a company known for this engineering prowess, this should not occur. If my brand new $130k 911 turbo sounded like a VW bus with a bad rod bearing, I'd be pissed.
Bob, I'd be interested in listening to this thing. While this may not be indicative of a dangerous problem, it would sure **** me off.
yes, there always be a little gear noise from the crank to IMS gears. I don't think anybody is going to cry about that. The fact that you bring up chain drives is irrelevant given that thousands of engines, including those in high end luxury sedans, use chains.
The air cooled mezger motors are naturally louder because they have no material between the cylinders to dampen the noise. But my 993TT doesn't have this rattle, and not all 996TT/997TT, GT3, GT2 or other mezger motors have this rattle.
Yes, there will be some tolerance stack, but given that these are flagship cars from a company known for this engineering prowess, this should not occur. If my brand new $130k 911 turbo sounded like a VW bus with a bad rod bearing, I'd be pissed.
Bob, I'd be interested in listening to this thing. While this may not be indicative of a dangerous problem, it would sure **** me off.
10-12-2011, 02:30 PM
#25
Race Director
like I said, I don't think it will ever present any problems, but man, I don't like unusual engine noises (well, I'm assuming most don't, but you know what I mean)
10-12-2011, 02:39 PM
#26
Drifting
Thread Starter
10-12-2011, 08:06 PM
#27
Race Director
sorry, no.
yes, there always be a little gear noise from the crank to IMS gears. I don't think anybody is going to cry about that. The fact that you bring up chain drives is irrelevant given that thousands of engines, including those in high end luxury sedans, use chains.
The air cooled mezger motors are naturally louder because they have no material between the cylinders to dampen the noise. But my 993TT doesn't have this rattle, and not all 996TT/997TT, GT3, GT2 or other mezger motors have this rattle.
Yes, there will be some tolerance stack, but given that these are flagship cars from a company known for this engineering prowess, this should not occur. If my brand new $130k 911 turbo sounded like a VW bus with a bad rod bearing, I'd be pissed.
Bob, I'd be interested in listening to this thing. While this may not be indicative of a dangerous problem, it would sure **** me off.
yes, there always be a little gear noise from the crank to IMS gears. I don't think anybody is going to cry about that. The fact that you bring up chain drives is irrelevant given that thousands of engines, including those in high end luxury sedans, use chains.
The air cooled mezger motors are naturally louder because they have no material between the cylinders to dampen the noise. But my 993TT doesn't have this rattle, and not all 996TT/997TT, GT3, GT2 or other mezger motors have this rattle.
Yes, there will be some tolerance stack, but given that these are flagship cars from a company known for this engineering prowess, this should not occur. If my brand new $130k 911 turbo sounded like a VW bus with a bad rod bearing, I'd be pissed.
Bob, I'd be interested in listening to this thing. While this may not be indicative of a dangerous problem, it would sure **** me off.
Many car makers fit rather exotic engine covers which dampen the noise from even these relatively quiet cam chain drive systems. I note the Turbo has nothing between the engine and blue sky other than an engine cover with lots of louvers.
The OP had the engine listened to by an experienced mechanic and the mechanic pronounced the noise normal. Which is another way of saying 'they all do that'. Which is where the OP had the chance to ask this be demo'd by hearing another engine fired up and run. Which he apparently chose not to have done, or least ask that it be done.
Anyhow, I do share some of your concern I think arising from the noise appearing suddenly. I would have no problems with the OP if he wanted to have this looked into further, get a second opinion, even go back to the tech and mention the noise level is new, that it has just appeared, and ask for more input based on that bit of additional information.
I will point out that sometimes an engine (car even) can get a bit noisier all of the sudden (so to speak) and this arises from a change in the weather, mainly when colder temps settle in.
Cars just get a bit noisier in colder weather because the pieces of the car fit together tighter, the rubber and other softer materials designed to dampen noise, curtail vibration, etc, are less good at this at lower temperatures and as a result these materials, the items made from them, transmit more noise and vibration and the car just emits a bit more noise. Some owners are more sensitive to this than others and it comes across as a drastic increase in noise.
Sincerely,
Macster.
