Odd metallic rattling noise with smell?
#1
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991.2 cabriolet with 37K miles. This morning, started the car up, lowered the top, and began driving down the street. Within the first 75 meters of driving, I started hearing a pretty loud rattling cacophony--it was loud enough that I thought it was a neighbor maybe having renovation work done or something. I stopped the car, the noise stopped. Started driving, the noise resumed. Then, within the next 30 seconds, the noise went away. I did detect a smell (hard to describe--perhaps something burning? but it was slight), but that went away, too.
Been driving the car around on a couple errands this morning--no more recurrence, even after startup.
Anyone have any clue what this might be? I've had this car for 1.5 years (I purchased it CPO with 30K miles on it) and have never experienced this phenomenon before.
Many thanks in advance for any insights anyone might have.
Been driving the car around on a couple errands this morning--no more recurrence, even after startup.
Anyone have any clue what this might be? I've had this car for 1.5 years (I purchased it CPO with 30K miles on it) and have never experienced this phenomenon before.
Many thanks in advance for any insights anyone might have.
Last edited by barrett; 10-28-2023 at 12:08 PM.
#2
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timing chain tensioner, perhaps?
#5
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Assuming that the noise started and stopped depending on the car moving (and not related to engine on/off), I would check the axles and see if you did not pick up something that wrapped around the axles/wheels?
#6
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OK - been thinking ... I should have asked the usual questions:
1. You were moving as you stated.
2. Was the engine warmed up?
3. Were you accelerating?
4. Turbo, right?
5. Manual or PDK?
6. Still under CPO warranty? (take it to check for codes, etc)
7. Any work been done to it recently?
1. You were moving as you stated.
2. Was the engine warmed up?
3. Were you accelerating?
4. Turbo, right?
5. Manual or PDK?
6. Still under CPO warranty? (take it to check for codes, etc)
7. Any work been done to it recently?
#7
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All good questions. Salient factors:
1. No work performed on the car recently.
2. Yes, noise occurred only when the car was moving--not correlated to the engine being merely on.
3. The engine was not warmed up. I was in my first drive of the way, within the first minute of driving.
4. Noise occurred while I was under throttle but not really accelerating. I was on my residential street with my 9-year old son in the back, just having backed out of our driveway.
5. 991.2 Carrera S, so yes, turbo model. PDK.
6. Still under CPO warranty.
Perhaps the most interesting factor is that, so far, other than that one instance, I have not experienced that noise again over the course of this weekend. Not while driving, not during a subsequent cold start, nothing. Odd.
1. No work performed on the car recently.
2. Yes, noise occurred only when the car was moving--not correlated to the engine being merely on.
3. The engine was not warmed up. I was in my first drive of the way, within the first minute of driving.
4. Noise occurred while I was under throttle but not really accelerating. I was on my residential street with my 9-year old son in the back, just having backed out of our driveway.
5. 991.2 Carrera S, so yes, turbo model. PDK.
6. Still under CPO warranty.
Perhaps the most interesting factor is that, so far, other than that one instance, I have not experienced that noise again over the course of this weekend. Not while driving, not during a subsequent cold start, nothing. Odd.