5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHIntermittent Engine Noise on Startup - Opinions?
Reported or suspected cause
1st (of 3) bad aos
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
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 report identifying a cause
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.
Reported cause
The only times my Boxster's idle speed varied was when what proved to be the 1st (of 3) bad AOS.
Leading evidence: '1st (of 3) bad aos' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is '1st (of 3) bad aos' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check scoring), intermix, etc' (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 report identifying a cause
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.
Reported cause
This proved to be a bad VarioCam solenoid/actuator.
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
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.
Performed · outcome unconfirmed · Original poster
It was tested for vacuum leaks and none were found.
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
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.
Suspected cause · Original poster
I believe it is due to a loose baffle in the exhaust or from the upper cam-chain tensioner (taking a moment to fill with oil).
Outcome qualification: Negation, uncertainty or missing explicit repair resolution overrides the raw extraction signal.
n/a 996 engine too)
Suggestion or failed attempt
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
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 suspect a cause
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.
Suspected cause
IIRC the factory says idle speed should be 740 +/-40 RPMs (and this is the same for my Turbo and I suspect for the N/A 996 engine too) but that is not to suggest the idle speed can vary.
Outcome qualification: Negation, uncertainty or missing explicit repair resolution overrides the raw extraction signal.
n/a 996 engine too)
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
Discussions that suspect a cause
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.
Suspected cause
IIRC the factory says idle speed should be 740 +/-40 RPMs (and this is the same for my Turbo and I suspect for the N/A 996 engine too) but that is not to suggest the idle speed can vary.
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.
5 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 · 1 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T205155Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Seller states the following:
1. On cold startup, after the car has been sitting for several days, there is a rattle for .5 seconds. This happens only on occasion. I believe it is due to a loose baffle in the exhaust or from the upper cam-chain tensioner (taking a moment to fill with oil). Either way, this is fairly normal and nothing to bring to concern.
2. It normally idles nicely between 740 and 760 rpm. Sometimes it drops down to 710 and feels a bit rough. Usually only for a moment but it does happen. No effect on drivability. It was tested for vacuum leaks and none were found.
Are these issues minor or a portent of some other serious issue to come down the road? What do you 996 experts think? Long time early 911 guy looking the purchase a 996 sometime.
It�s purely anecdotal evidence but I think a lot us on here experience some chain rattle after startup. If the noise doesn�t go away then you�ve potentially got bigger issues (bore scoring, etc.).
Porsche owners (including myself) can be oversensitive about start up noises. These noises are often normal for the start up procedure such fuel prime, SAI, and yes, the chain tensioners and become more pronounced as the car ages. On that note, I assume this is a car you're considering buyer since you said "seller"? If so, your best defense is a good offense. Have a PPI conducted by a respected Porsche shop in the area.
Your biggest concerns should be related to the core modes of failure such as IMS bearing, cylinder health (check for scoring), intermix, etc. Then, consider general engine health - metal in the filter/sump, any leaks, fuel trim/injectors issues, over-revs, etc. Those items would be higher on my priority lists. Things like cosmetics and easy DIY wear items (e.g. brakes, water pump, belts, switches, radio, etc.) can be fixed without a lot of costs.
Agree with the above. Particularly a good PPI at a qualified shop! Year of car could be valuable in guesstimates. Bore scoring from my experience doesn't just make noise on a "dry" start-up. Mine was a tick-tick-tick that got worse as the engine warmed up turning into a significant noise. PPI should include a look at the liners from the bottom if possible and allowed by seller.
You or someone that can make a high confidence judgement call regarding the noise at start must hear it. One man's normal and nothing to bring any concern engine startup noise is another man's engine death rattle.
IOWs, while some startup noise is common and normal I would not rely upon the seller's opinion.
My experience is with my 2002 Boxster the idle speed is pretty steady. IIRC the factory says idle speed should be 740 +/-40 RPMs (and this is the same for my Turbo and I suspect for the N/A 996 engine too) but that is not to suggest the idle speed can vary. The only times my Boxster's idle speed varied was when what proved to be the 1st (of 3) bad AOS. It was the slight (but noticeable) down and up albeit not a large swing in idle speed that clued me in something was wrong. It took other symptoms to appear -- which they did after not much time -- to make it clear that I was not going to fix this in my garage.
The other time the idle speed went down and up by larger amounts and on the low end the idle speed dropped to the point I thought the engine was going to die. This proved to be a bad VarioCam solenoid/actuator.
Surprisingly there was no CEL but there was a pending code which pointed to the VarioCam solenoid/actuator.
This is a source reference. Confirm exact model applicability in the original material.
