11 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH996 3.4 misbehaving
Reported or suspected cause
afm sensor
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
I had a similar issue with my 996.2 and after checkign with Durametic, it turned out to be an AFM sensor which was a $150 and 10 minutes with a torx bit to fix.
Leading evidence: 'afm sensor' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'afm sensor' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Clean with proper afm cleaner (supercheap 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 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
I ended up doing a AOS sometime later and also changed the waterpump as the bearing started to get quite noisy.
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
Driven on weekends only and serviced late last year (they said the AOS was leaking and tightened the clamp on one of the lines).
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
Can try to remove and clean with proper AFM cleaner (Supercheap etc.
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
Replace AOS (pain is the A** to do but common issue)
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
afm sensor
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
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
I had a similar issue with my 996.2 and after checkign with Durametic, it turned out to be an AFM sensor which was a $150 and 10 minutes with a torx bit to fix.
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.
11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Porsche Forum Australia: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
Durametric is the go, but I got one of the iCarsoft Por V2 units for $250 which reads all the general OBD codes as well as Porsche specific codes - it will also clear your codes once you've fixed the issue.
Hello all,
I have a misbehaving 996. Has developed symptoms where she wont idle - keeps hunting revs (between 1000-1900rpm) like I'm warming up a race car motor.. Did it a few times then stopped but now does it all the time, even after she is warmed up... It is as if the choke is stuck on or there is a vacuum issue somewhere.
I'm going to take her to Buiks but I wondered if anyone else here with a 3.4 has had similar issues.
996 - 1998 3.4 with about 160k on the clock. Driven on weekends only and serviced late last year (they said the AOS was leaking and tightened the clamp on one of the lines).
Its bloody embarrassing as it sounds like I'm a hoon at the lights - I have stopped driving her which I hate because what's the point...
Suspect might be plug packs? Should show up on scan tool? I was going to suggest might also be sticking variocam actuators, but unless I'm mistaken (quite possible!!) variocam not introduced until the 3.6L in the 6.2
First step would be to get am OBD2 diagnostic done. If you can get hold of a Durametric (IMHO the best ODB2 scan tool) or another scan tool you could see what error codes are being thrown if any. I had a similar issue with my 996.2 and after checkign with Durametic, it turned out to be an AFM sensor which was a $150 and 10 minutes with a torx bit to fix.
AFAIK, typical issues for poor idle on a 3.4 could be:
1: As mentioned by
@TwoHeadsTas
, coils and/or plugs.
2: AFM/MAF sensor failure - usually associated with an ABS / PSM failure. Can try to remove and clean with proper AFM cleaner (Supercheap etc. sell this one) see if it resolves ($20 and 10 mins to exclude or see if it makes a difference).
3: Idle control valve blocked/failed - if stuck open /blocked can cause lean running, inspect and clean.
4: Air/Oil seperator failure - intake post throttle very oily. Replace AOS (pain is the A** to do but common issue)
5: Vacumm leak due to cracked hose etc. - hard to run down, but visual insprection of hoses is a good start for crack or poor connection
6: Fuel system - If fuel pressure is waivering, pump or fuel filter could be on the way out or blocked.
My coil pack failure certainly gave similar symptoms as you've described - do you have a Check Engine Light (CEL) displayed? Coil failure throws the CEL up on the instrument panel. As suggested, grab some form of OBD tester. Durametric is the go, but I got one of the iCarsoft Por V2 units for $250 which reads all the general OBD codes as well as Porsche specific codes - it will also clear your codes once you've fixed the issue.
Hopefully it's one of the minor issues these cars get and is just a weekend fix.
I also have the iCarSoft which can be used in the car without computer interface. It does sound like a coil pack prob but could also been O2 sensor. Read those codes or it is just expensive guess work.
Thanks so much guys. I will try these out this weekend and report back - fingers crossed.
I have a Bosch oBD2 scanner - haven’t tried it on the 996 so will try that first.
No CEL and the throttle body is as clean as new.
Didn't realise I hadnt come back and posted what the issue was...
So after leaving it for a while I (long enough to need a new battery
😕
) Ifinally got time to take her to Buiks.
Guys there found that the airbox must have not been closed properly or a bump had opened it and hence a vacuum leak...
New battery and some labour and she was good to go again!
I ended up doing a AOS sometime later and also changed the waterpump as the bearing started to get quite noisy.
Just need some decent weather now to get her out more often...
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