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996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

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YOUR RESEARCH996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

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Clean /

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Discussions that performed work without a confirmed outcome: 1

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Performed · outcome unconfirmed
I have removed & cleaned/resealed a few over the years...it's a time consuming process but not too bad with the right tools.
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996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

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Leading evidence: 'Clean /' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Clean /' (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.

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Reseal few over the years...it's a time consuming process

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Discussions that performed work without a confirmed outcome: 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.

Performed · outcome unconfirmed
I have removed & cleaned/resealed a few over the years...it's a time consuming process but not too bad with the right tools.
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996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Replace aos breather valve (crankcase vent valve)

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Suggestion · Original poster
Anyone have a DIY guide on replacing the AOS Breather Valve (Crankcase vent valve) on the passenger side of the vehicle.
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996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Replace cracked breather tube is a much bigger job

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Unsuccessful attempts: 1
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Discussions that contain suggestions: 1

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Suggestion
Replacing a cracked breather tube is a much bigger job!
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996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Test blow-by

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Suggestion
Cap it off then Test the Blow-by using my procedure here ..
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996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Frequently discussed actions (7)

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Clean /

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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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
I have removed & cleaned/resealed a few over the years...it's a time consuming process but not too bad with the right tools.
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Replace aos breather valve (crankcase vent valve)

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 · Original poster
Anyone have a DIY guide on replacing the AOS Breather Valve (Crankcase vent valve) on the passenger side of the vehicle.
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Replace cracked breather tube is a much bigger job

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
Replacing a cracked breather tube is a much bigger job!
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Reseal few over the years...it's a time consuming process

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

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
I have removed & cleaned/resealed a few over the years...it's a time consuming process but not too bad with the right tools.
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Test blow-by

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
Cap it off then Test the Blow-by using my procedure here ..
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Test shows excessive crankcase pressure

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
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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
If the Blow-by Test shows excessive crankcase pressure then install the UAOS System (
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Use procedure here

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
Cap it off then Test the Blow-by using my procedure here ..
Original post Read captured discussion
996.1 3.4L AOS Breather Valve and O Ring Replacement Advice

Coverage and how to read this overview

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.

8 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.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T161109Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Hello, Anyone have a DIY guide on replacing the AOS Breather Valve (Crankcase vent valve) on the passenger side of the vehicle. It is a 1999 996.1 3.4L. There are some hoses in the way which make access tight. Anyone done this before and has a guide? It is this piece here: https://www.pelicanparts.com/More_In...SABEgJOQPD_BwE Thanks in advance

POST 2Original post

It's a PITA to get to due to much stuff in the way ... IF it is leaking oil my advice is to "Cap it off" ... the 996.2 doesn't have this over-pressure valve, it is suppose to only open if there is excessive crankcase pressure... Cap it off then Test the Blow-by using my procedure here .. https://rennlist.com/forums/996-foru...=engine+health If the Blow-by Test shows excessive crankcase pressure then install the UAOS System ( www.ultimateaos.com ) and drive on ...

POST 3 / ORIGINAL POSTEROriginal post

Appreciate the advice. Yes, it looks like a PITA to get to and exchange without removing a ton of stuff. Also would look like the same PITA for capping it off. Any suggestions there?

POST 4Original post

Quotes source post: 20148823

Patience...LOTS of patience... Some Beer, Bourbon may help also ....Long sleeves/gloves to keep your arm from getting greasy... Take the engine lid off/out of the way so you can get a better sight angle on it ... ( there is only one bolt holding it on )

POST 5 / ORIGINAL POSTEROriginal post

Quotes source post: 20148883

Good advice with regards to the engine lid. May try that

POST 6Original post

I have removed & cleaned/resealed a few over the years...it's a time consuming process but not too bad with the right tools. It's tricky getting to the hold-down bolt!

POST 7 / ORIGINAL POSTEROriginal post

Quotes source post: 20150357

Any advice or specific tools you can recommend?

POST 8Original post

Quotes source post: 20151454

I can't recall specific tools at the moment, but being gentle with the plactic pipe connected to the breather valve is critical. Replacing a cracked breather tube is a much bigger job!

This is a source reference. Confirm exact model applicability in the original material.