Knocking sound in my 997 - 2007
10-06-2015, 05:54 AM
#1
3rd Gear
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Knocking sound in my 997 - 2007
Hi all,
I have bought a 2007 carrera and there is a sound (knocking sound) in my car for a couple of secondes when I start it up cold.
The sound is gone after 5-10 seconds. When I start it up warm, there is no such sound. Only when it´s cold again after 7-8 hours.
Can anyone please help me?!
NP
I have bought a 2007 carrera and there is a sound (knocking sound) in my car for a couple of secondes when I start it up cold.
The sound is gone after 5-10 seconds. When I start it up warm, there is no such sound. Only when it´s cold again after 7-8 hours.
Can anyone please help me?!
NP
10-06-2015, 07:39 AM
#2
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Should be normal. Can you post a sound clip? Ask a local Porsche enthusiast to take a listen?
Mileage?
Last oil change?
What oil? Brand & viscosity?
Mileage?
Last oil change?
What oil? Brand & viscosity?
10-06-2015, 07:58 AM
#3
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Milage 70 000 km
Last oil change 10 000 km ago and one year
Done at Porsche center so I have to check the specification of the oil.
I have attached a film in my first post. Can´t you hear that?
Last oil change 10 000 km ago and one year
Done at Porsche center so I have to check the specification of the oil.
I have attached a film in my first post. Can´t you hear that?
10-06-2015, 09:32 AM
#4
Team Owner
The first thing you should know is this is not the correct forum for your question, although the odd guy on this forum may own a 997 the vast majority do not. You will get much better response in the water cooled section of this web site under 997.
Good Luck .
Good Luck .
10-06-2015, 09:37 AM
#5
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Good point. I miss that. I'll ask a mod to move this to the 997 forum.
10-06-2015, 09:55 AM
#6
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I hear a quick tapping/clicking and it's not even 5 secs, it's more like a second or two. It's really hard to say. It could be anything from a lifter stuck to a timing chain slapping something until the oil gets up to pressure. I don't think it's piston slap or anything like that.
The other sounds are normal cold start sounds.
Definitely have an indy or someone to look at it though.
Mike
The other sounds are normal cold start sounds.
Definitely have an indy or someone to look at it though.
Mike
10-06-2015, 10:05 AM
#7
When I read the first post I thought it was going to be bad.
The sound is pretty subtle.
I'll let the experts decide, not my 2 cents
Does your car have any mods ? Stock 997 (2007) ?
The sound is pretty subtle.
I'll let the experts decide, not my 2 cents
Does your car have any mods ? Stock 997 (2007) ?
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10-06-2015, 10:30 AM
#9
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That's kind of strange. I hear a normal start, then a couple seconds of slight tapping, then it clears quickly. I'd expect to hear the slight tapping almost instantly, not delayed like yours. Have it looked at by a knowledgeable person locally.
10-06-2015, 10:41 AM
#10
Instructor
Where is Sweden do you live? If you live near gothenburg and ever got a problem, I'd suggest you to visit rennsport for such matters. (http://www.rennsport.se/)
And are you reffering to the mechanic rattleound you can hear for a second or the "avgassmällar" from the exhaust system. If you're reffering to the exhaust part, then that's normal while the car is cold. I have them as well.
The rattle however is probably the chain stretchers. Common problem on the 996 using the same 3.6 L engine as your carrera. I know for a fact that the boxster has had some problem with it as well. My old 98 boxster I had a few years ago used to rattle a little for just a second or a half once I started the engine cold and would then dissapear.
You could always try a little thicker oil, might help.
And are you reffering to the mechanic rattleound you can hear for a second or the "avgassmällar" from the exhaust system. If you're reffering to the exhaust part, then that's normal while the car is cold. I have them as well.
The rattle however is probably the chain stretchers. Common problem on the 996 using the same 3.6 L engine as your carrera. I know for a fact that the boxster has had some problem with it as well. My old 98 boxster I had a few years ago used to rattle a little for just a second or a half once I started the engine cold and would then dissapear.
You could always try a little thicker oil, might help.
10-06-2015, 10:45 AM
#11
Three Wheelin'
If this car sat before sale, I'd add the highest octane fuel and quality fuel system cleaner.
Where do you live? If you have old fuel, which was barely 91 octane to begin with, and the tank was low, and it is summer blend and it's suddenly 40 degrees in the morning.... well... you don't have the best fuel.
This sounds like a cheap fuel problem to me. At start up, the computer has to set things up for a cold start and then react to whatever crap fuel is in there.
Highest octane fuel, plus high quality fuel treatment, then a thorough series of runs up to 6000+ RPM after the oil is up to hot operating temp (200+ Farenheit or near 100 C).
.
Where do you live? If you have old fuel, which was barely 91 octane to begin with, and the tank was low, and it is summer blend and it's suddenly 40 degrees in the morning.... well... you don't have the best fuel.
This sounds like a cheap fuel problem to me. At start up, the computer has to set things up for a cold start and then react to whatever crap fuel is in there.
Highest octane fuel, plus high quality fuel treatment, then a thorough series of runs up to 6000+ RPM after the oil is up to hot operating temp (200+ Farenheit or near 100 C).
.
10-06-2015, 11:19 AM
#12
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Hi again,
It is not the exhaustnoise which is bothering me it is the other sound which you can hear for a couple of seconds.
Holma I live in Motala and I wrote an email to rennsport and I attached the Movie.
No modifications on the car...all standard.
I have heard about a cold start valve??? What is that?
About the fuel. I allways fill it up with 98 octane and I have been driving it quite hard a few times. Same sound when I start it cold. No change at all.
It is not the exhaustnoise which is bothering me it is the other sound which you can hear for a couple of seconds.
Holma I live in Motala and I wrote an email to rennsport and I attached the Movie.
No modifications on the car...all standard.
I have heard about a cold start valve??? What is that?
About the fuel. I allways fill it up with 98 octane and I have been driving it quite hard a few times. Same sound when I start it cold. No change at all.
10-06-2015, 12:53 PM
#13
Instructor
He lives in sweden, currently quite cold in the country over all. And as for the gasoline being sold, there's 3 options.
95, 98 and Shell v-power "99 octane".
95, 98 and Shell v-power "99 octane".
10-06-2015, 01:25 PM
#15
RL Community Team
Rennlist Member
Rennlist Member
I think it is classic rotted muffler supports. When you start the car, immediately put your foot on the tailpipe and press. If the sound stops, it is a simple tack weld.
Try it,
Peace
Bruce in Philly
Try it,
Peace
Bruce in Philly
