16 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHLoud Groan at first startup of the day.
Leading reported evidence
Replace serpentine belt
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed
I had this on my former 996, I replaced the serpentine belt with one from the brand Continental.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
You can remove the belt -- after you have carefully noted the routing and the direction the belt runs in so you can reinstall it the same as it was before you removed it -- and check all accessory drives for excessive bearing/shaft play.
Leading evidence: 'Replace serpentine belt' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'still present' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check accessory drives' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
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Suspected cause
If it always does this @ first start of the day, you could disconnect the pump's electrical connection and see if the problem is still present.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
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0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
You can remove the belt -- after you have carefully noted the routing and the direction the belt runs in so you can reinstall it the same as it was before you removed it -- and check all accessory drives for excessive bearing/shaft play.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Get it on a lift and check the water pump for leak sign and the serpentine belt for signs of wear/sharp edges.
Inspect without removing the transmission does not have
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
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Suggestion
Can also add that what might seem like an RMS leaking, inspected without removing the transmission does not have to be that.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check accessory drives
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
You can remove the belt -- after you have carefully noted the routing and the direction the belt runs in so you can reinstall it the same as it was before you removed it -- and check all accessory drives for excessive bearing/shaft play.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
16 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
2 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
I have tried it with HvAC on and off with no change.
I am getting a loud groan ( not like a rattle but sounds like accessory belt whine but deeper) at the first start up of the day. Won't donit again unless it has sat for more than 7 hours. Also it is not very consistent. I just left the car sitting for 8 hours and started it and it didn't do it. ( was going to film it)
Car runs really well, no crazy symptoms and the noise goes away in less than 3 seconds. Almost sounds like when a belt driven air compressor tries to crank in the cold.
I have had cars with timing chain rattle (bmw's and a mustang gt) and I dont believe this is that.. It sounds like rubber not metal or plastic.
It's hard to guess based on the description - but I'm going with the air injection pump. All in.
OP, this pump is used to help the catalytic converters work more efficiently when the engine is cold, which might explain why it only happens when the car is not warmed up.
If it always does this @ first start of the day, you could disconnect the pump's electrical connection and see if the problem is still present.
I have heard this sound also. I would describe it as a rubber eraser running on a chalk board for a second. Like an air pump or the like. Curious to see what others say - sounds like it comes from under the battery...
You have to, well make that should, get the car inspected. Get it on a lift and check the water pump for leak sign and the serpentine belt for signs of wear/sharp edges. You can remove the belt -- after you have carefully noted the routing and the direction the belt runs in so you can reinstall it the same as it was before you removed it -- and check all accessory drives for excessive bearing/shaft play.
The start up noise can be a dragging starter overrun clutch. My Boxster was making this noise sometime back but I haven't heard it for a long time, several months maybe more. But it is getting a bit cooler again here so maybe the noise will reappear.
A bad AOS can make a noise or in some cases it can cause extremely low pressure in the engine crankcase and the RMS (or the FMS) can let air past and this can make a noise.
The loose spark plug offered up by DB996Joe can't be overlooked either.
It's like that abdominal pain that goes away as soon as you make a doctor's appointment.
One Post on RennList. *POOF*
Did you give it a bit of gas when you started it ? Sounds like it. (Guessing you didnt). Cool recording. Very helpful for others.
Ahsai, Thank You SO Much for posting that video to ID the screeching sound as the starter. While I'm not the OP, just this AM my new-to-me (3 days!) C2 made the same sound. I was immediately thinking IMS bearing.
I feel much better now!
Carl
Do you experience this sound in any weather, wet and dry?
I had this on my former 996, I replaced the serpentine belt with one from the brand Continental. Which is a highly regarded brand in Europe. Started noticing that when raining or damp it started making noise on start-up. When I pull out of my driveway I need to manuver a bit causing some more water to hit the belt, making it squeak again. This did not happen when the motor was warm even during rain, only when cold.
Can also add that what might seem like an RMS leaking, inspected without removing the transmission does not have to be that.
My friend and me both had the same car, both thought the RMS was leaking, both had old and broken oil filler pipe. Upon replacing our oil filler pipes both discovered that the pipe was leaking at the base. The o-ring did not provide a sufficient seal making it seep oil, which again dripped the identical route as an RMS failure will. We both discovered a small puddle of oil on top of the engine due to this, when decelerating or parking in a steep downhill this puddle began to run down the transmission.
After the oil filler pipe and o-ring replacement no more leaks and we both concluded that it was not the RMS.
This is a source reference. Confirm exact model applicability in the original material.
