fullymatted.
Back to search
986Forum

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Add to repair workspace
Open repair workspace
Original source
13 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHengine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Reported or suspected cause

alternator

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

Just to update the thread, my mechanic found out it was the alternator!

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Frequently discussed work

Replace with a bosch refurbished one

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

So getting that replaced with a Bosch refurbished one.

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Read full discussion summary

Leading evidence: 'alternator' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'alternator' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Replace with a bosch refurbished one' (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 · 13 captured posts examined · 0 partial discussions

Compare 2 other evidence results

Replace with a bosch refurbished one

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

So getting that replaced with a Bosch refurbished one.

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run mobil 1 0w40

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

Are you running Mobil 1 0W40?

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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 with a bosch refurbished one

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

So getting that replaced with a Bosch refurbished one.

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run mobil 1 0w40

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

Are you running Mobil 1 0W40?

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Reported and suspected causes (1)

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

alternator

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

Just to update the thread, my mechanic found out it was the alternator!

engine idle noise... - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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.

13 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • 986Forum: 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

Problem solved.

No unique explicit quoted action; no causal link assigned

Generation: 20261026T113718Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I've noticed recently that when my car is idling I hear a random clicking or ticking or various inconsistent tapping sounds from the car, I don't know for certain it's coming from the engine.......anyone encountered a similar experience. Is this serious? Sorry for the vague and general descrip. TIA.

POST 2Original post

What year is your car? Mileage? Model? Are you running Mobil 1 0W40? How is your oil level? Are you sure this is not the cats cooling off or heating up?

POST 3Original post

Sounds like your Cats and Exhaust heating and cooling.

POST 4 / ORIGINAL POSTEROriginal post

1999 boxster 52k M1 0w40 every 3-5k I haven't noticed any performance depreciation. You must be right about the cats. Thanks for the replies.

POST 5Original post

My neighbor had a cat crawl up into his car to keep warm one night and wow, it made a real racket when he was warming up the car the next day... but only for a little while and then it was all quiet and no more cat noises whatsoever. :dance:

POST 6Original post

Sorry to revive an old thread, but I have exactly the same issue on my 2001 986 S. It happens only at idle, and is an intermittent (ie. once every 1-3 seconds) clinking or tinking, metallic sound like flicking a thin piece of metal with your fingernail. This occurs well after the car is warmed up, and did not used to happen, so it is not normal metal expanding. Any ideas?

POST 7Original post

I had a similar noise on mine -did a big search on here and it could be one of three things: 1. Damaged CAT honeycomb - tap the cats with a rubber mallet when the car isn't running to see if they rattle. 2. Loose heat shield - give them a wobble to see if they've worked free. Or.. 3. (which I found myself) The sensors screwed into the top of the CATs can unscrew themselves, and will rattle like you describe - both my CATs did it one after the other (one twice). Reach up and check them (not when the car's warm though). Hope this helps!

POST 8Original post

Note that there are two kinds of heat shields around that area. The first is the shiny aluminum stuff that is easy to bend and can easily cut you if you graze it just right. If the edge of some of this stuff is touching part of your exhaust, it may buzz or make noise. The other heat shield is steel, which loosens with age and heat expansion/shrinking. It's found ahead and behind your cats. I had a vexing, tinny rattle at certain low rpm's that turned out to be one of these heat shields. I put the back of the car on ramps, started the engine, asked the wife to rev it a bit, slid under the car, found it, and whacked it real good with a hammer a few times to bend it and make it fit tightly against the piping after the cat. Problem solved. And whacking the crap out it with a hammer after six months of listening to it was very satisfying indeed

POST 9Original post

In general, I've found that any engine noise I really need to worry about makes itself known to me quickly and loudly. Make sure your oil level is correct and belts tensioned properly. Beyond that, any minor taps and clicks are best ignored, it's easy to get obsessed about them.

POST 10Original post

Thanks for info guys...I'm taking it to my mechanic tomorrow am to let him have a look/listen. I am wondering if it's maybe something to do with the clutch mechanism..just a gut feel. It seems my clutch is rather grabby lately, and I also notice that I hear the same type of rattling type of noise at a certain point as I engage it.

POST 11Original post

Just to update the thread, my mechanic found out it was the alternator! So getting that replaced with a Bosch refurbished one. As usual, not cheap, $700 for the whole job including the part.

POST 12Original post

Man that is a lot of money for a rebuilt unit. Glad you found out what the issue was.

POST 13Original post

He had to spend some time figuring out what exactly the problem was, so for that, and the part, and installing the new part, I am ok with it.

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