Rennlist

996 Heads & Valves - Recommendations

Add to repair workspace

New repair projectOpen repair workspace

Original source

5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCH996 Heads & Valves - Recommendations

Leading reported evidence

Replace lifters, chains, chain guides, chain tensioners, etc

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

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 changing lifters, chains, chain guides, chain tensioners, etc.
Original post Read captured discussion
996 Heads & Valves - Recommendations

Read full discussion summary

Leading evidence: 'Replace lifters, chains, chain guides, chain tensioners, etc' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace lifters, chains, chain guides, chain tensioners, 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.

Read captured replies

1 matching discussions · 5 captured posts examined · 0 partial discussions

Compare 1 other evidence results

Test leak down

Suggestion or failed attempt

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
Without cams, you should be able to test leak down on all cylinders.
Original post Read captured discussion
996 Heads & Valves - Recommendations

Frequently discussed actions (2)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Replace lifters, chains, chain guides, chain tensioners, etc

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 · Original poster
I ended up changing lifters, chains, chain guides, chain tensioners, etc.
Original post Read captured discussion
996 Heads & Valves - Recommendations

Test leak down

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
Without cams, you should be able to test leak down on all cylinders.
Original post Read captured discussion
996 Heads & Valves - Recommendations

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.

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 · 0 adjusted by outcome qualification.

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

Generation: 20261026T105141Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Have a 2000 996 C2 engine that I partially disassembled to correct timing, do IMS/RMS and eliminate potential issues found with metal in sump, which I fortunately ruled out concerns. I ended up changing lifters, chains, chain guides, chain tensioners, etc. Unfortunately upon reassembly, I'm getting air loss out of multiple cylinders (exhaust side), and now needing to take off heads to see if I did any damage to valves or if there was an issue simply revealed by disassembly / new parts. I'm not looking to do a full rebuild of heads, and certainly don't want to go any deeper at this point, so curious... - Any general recommendations of what to do at a minimum? - Anyone in the CA Bay Area have a machine shop they can recommend? - Are there things I can / should do before taking the heads to the shop? - In the work I've done, I've generally gone Porsche or OEM, with some OE on minor stuff. Any suggestions on valve related items what to go with?

POST 2Original post

Multiple cylinder air loss, I think you got your cam timing all wrong.

POST 3Original post

Could your hydraulic tappets be overfilled with oil? Or could be cam timing?

POST 4 / ORIGINAL POSTEROriginal post

Quotes source posts: 18254210, 18254833

That's what I thought, but same issue after removing cams. Thought a combination of these, but same thing after removing cams. Being new to this, not sure that doing leak down with cams out vs cams in is the same. Valves look closed with borescope / light, so can only think some carbon got loosened in process or valves stuck a minuscule level either because I inadvertently bent them slightly or for lack of lubrication. Before taking heads off, maybe I reassemble head again and check.

POST 5Original post

Quotes source post: 18258130

Without cams, you should be able to test leak down on all cylinders. A bent valve leaks without cam shaft. If you put cams back and they then leak, it's timing.

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