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Engine Tapping After Oil/ Muffler Change

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11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHEngine Tapping After Oil/ Muffler Change

Leading reported evidence

Check million times and i sufficient oil

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 have checked a million times and I sufficient oil.

Engine Tapping After Oil/ Muffler Change
Frequently discussed work

Check clamps

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

Check clamps on the cat

Engine Tapping After Oil/ Muffler Change
Read full discussion summary

Leading evidence: 'Check million times and i sufficient oil' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check clamps' (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.

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1 matching discussions · 11 captured posts examined · 0 partial discussions

Compare 4 other evidence results

Replace mufflers

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 also changed mufflers from 3.4l stock to 3.6l stock.

Engine Tapping After Oil/ Muffler Change

Performed · outcome unconfirmed · Original poster

I actually changed the mufflers because of a broken baffle in my old ones.

Engine Tapping After Oil/ Muffler Change

Replace oil in my 99 996 c2

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 recently changed the oil in my 99 996 c2.

Engine Tapping After Oil/ Muffler Change

Check clamps

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

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

Check clamps on the cat

Engine Tapping After Oil/ Muffler Change

Disconnect electrical

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

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

To eliminate this as the source of the noise, simply disconnect the electrical to the valve while engine is running.

Engine Tapping After Oil/ Muffler Change
Frequently discussed actions (8)

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

Check clamps

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

Check clamps on the cat

Engine Tapping After Oil/ Muffler Change

Check million times and i sufficient oil

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 have checked a million times and I sufficient oil.

Engine Tapping After Oil/ Muffler Change

Disconnect electrical

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

To eliminate this as the source of the noise, simply disconnect the electrical to the valve while engine is running.

Engine Tapping After Oil/ Muffler Change

Replace mufflers

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 also changed mufflers from 3.4l stock to 3.6l stock.

Engine Tapping After Oil/ Muffler Change

Performed · outcome unconfirmed · Original poster

I actually changed the mufflers because of a broken baffle in my old ones.

Engine Tapping After Oil/ Muffler Change

Replace oil in my 99 996 c2

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 recently changed the oil in my 99 996 c2.

Engine Tapping After Oil/ Muffler Change

Replace sound

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

On a lift, you can remove the heat shields and look and often, spraying a bad coil with water will change the sound.

Engine Tapping After Oil/ Muffler Change

Replace unless something went wrong

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

Oil related tapping sound are usually always present and not just because of an oil change unless something went wrong with the change that blocked an oil circuit which is unlikely.

Engine Tapping After Oil/ Muffler Change

Replace viscosity

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

I did change the viscosity from 0w-30 to 10w-40.

Engine Tapping After Oil/ Muffler Change
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.

11 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 think that you may have solved the problem.

No unique explicit quoted action; no causal link assigned

Generation: 20261026T203514Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I recently changed the oil in my 99 996 c2. I also changed mufflers from 3.4l stock to 3.6l stock. I now have a rpm related engine tapping sound. It is constant, faster with increased rpm's. Seems to be coming more from the passenger side of the engine. I read that if not enough oil is added after an oil change that you may here valve tapping. I have checked a million times and I sufficient oil. I have a 914, my 996 now sounds similar to the 914 (at least the valves). The car runs great. Other than the mufflers, everything is stock. Has about 55k miles. No known problems other than a minor RMS leak. Anybody familiar with this issue? I do not know if it is normal and I had never noticed it before or if it is related to the oil or muffler change? Thanks again for your help

POST 2Original post

I bet its the muffler. The baffles inside mught have came loose making a rattling sound. Oil related tapping sound are usually always present and not just because of an oil change unless something went wrong with the change that blocked an oil circuit which is unlikely.

POST 3 / ORIGINAL POSTEROriginal post

I've noticed that it will be there sometimes and not others. Sometimes it is louder than others. I have good oil pressure. If I clogged the oil system somehow, shouldn't I have a decrease in pressure? The sound really sounds like valve tapping however it is not characteristic. I actually changed the mufflers because of a broken baffle in my old ones. This sound is different- more of a tapping than a rattle. Is it possible that an exhaust leak could cause a tapping sound? Thanks

POST 4Original post

An arching ignition coil can also produce a tapping sound.

POST 5 / ORIGINAL POSTEROriginal post

Got any good ways to diagnose an arching coil other than just looking at it. I looked and I saw no eveidence of arching. Thanks for all of your help!!!

POST 6Original post

The flat six is harder since you can't look directly at the coils from above. If it was arching badly, you may see it in the dark. On a lift, you can remove the heat shields and look and often, spraying a bad coil with water will change the sound. Make sure you are not simply hearing the egr valve located inline to the throttlebody right above the alternator. To eliminate this as the source of the noise, simply disconnect the electrical to the valve while engine is running. Valve noise will also decrease when the viscosity of oil is increased.

POST 7 / ORIGINAL POSTEROriginal post

I think that you may have solved the problem. I did change the viscosity from 0w-30 to 10w-40. The sound doesn't really bother me- it reminds me of the air-cooled porsches. Thanks, Steve

POST 8 / ORIGINAL POSTEROriginal post

-Also, A good way to take a look at the coil is with a flexible borescope. It is somewhat hard to see details but it is fun to use.

POST 9Original post

Could be a small exhaust leak Check clamps on the cat Realign and retighten the exhaust tips Only thing that changed was the oil and exhaust

POST 10 / ORIGINAL POSTEROriginal post

Yes, only thing that changed was the oil and exhaust. I believe that I may have a slight leak from the cat clamp. Also, for some reason, I had an unusually difficult time aligning the tips. Does anybody have any hints for tip alignment, it is such a pain.

POST 11Original post

No tip, It's a pain in the A** I tighten it enough so that it's tight but still can move with a little force. Worked for me

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