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Geflackt

Tapping noise - Hot and Idle.

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Another tapping noise post....

 

Picked up an '06 Boxster S at Christmas.  Decided on something more modern after racing a '35 MG special, 50's Alfas, and other British.  First time with Porsche!

 

There is a tapping noise at hot idle that is driving me nuts trying to find.  Here's what's known so far:

- Engine has 75k miles and doesn't seem abused.  Original owner car.

- The noise is not an accessory on the belt.  Tested briefly with belt removed.

- Updated the oil pressure piston and spring per the TSB.  The engine is just before the TSB was issued.

- Oil and filter changed recently by the dealer.

- Dealer listened for noise and said it's on bank 2 above oil filter somewhere.

- The noise goes away by 1krpm with light throttle.

- The engine is amazingly quiet at cold, even after sitting for a few days.  Very quiet up until it gets to normal operating temperature.  The injectors are the bulk of the noise.

- After revving the engine up around 3k and dropping, the tapping may not come back for 30 seconds.

- On restart at normal temperature, it may be up to a minute before it returns.

- The noise seems to go away when the oil cap is removed.  There is a slight draw on the cap but nothing keeping it from coming off easily.

- I disconnected the AOS from the intake and plugged the ports to the air intake.  No difference.

- With a stethoscope, the noise is most noticeable towards the front top area.  Not a lot of noise near the heads.

- Exhaust bolts tight.

- Cam angles look OK using a Durametric but I need to research this area a little more.

 

I have a set of plugs to change out as part of maintenance, but otherwise I'm stumped at the moment.  I'll record a file of the sound and post it soon.

 

Ideas or thoughts?
Thanks!
Jay.

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Have you checked that the spark plugs are all torqued correctly? There have been a few cases over the years where a loose plug caused an odd noise.

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Have you checked that the spark plugs are all torqued correctly? There have been a few cases over the years where a loose plug caused an odd noise.

 

If there was a plug issue, would I see a CEL or other codes?  There is no CEL and no stored codes.

Planning on starting to change plugs today.

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A few additional points:

- The frequency seems like it's on 1 cylinder.  The tap is approx 4 or 5 Hz.

- Going through the Excel sheet of the cam readings, the 2 banks are within 1 or 2 degrees of each other and are well within the 6 degrees nominal from idle to about 3k.

- No CEL's or codes.

- Once up to op temp, the engine does seem a little rough at idle, as if "out of tune".  Going to start a plug change today and clean the MAF.  The air filter was dirty and I have a replacement.

 

Jay.

 

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Have you checked that the spark plugs are all torqued correctly? There have been a few cases over the years where a loose plug caused an odd noise.

 

If there was a plug issue, would I see a CEL or other codes?  There is no CEL and no stored codes.

Planning on starting to change plugs today.

 

 

No, loose plugs typically cause a loss of compression and noise, but no CEL.  Quite often, the driver doesn't even notice a loss of performance.

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Changed out the plugs today.  Seemed to have even torque all around.  Plugs all looked even with just a hint of oil.  Found one coil pack having cracks starting, but it's not on the side that seems to have the tapping.  Idle is still a little "nervous", but I didn't disconnect the battery or reset anything.

 

The tapping is still there, though.  No difference after changing the plugs.  I captured a few sound clips and will be posting soon.  It really seems to be around the left side, bank 2.  With a stethoscope I can still only pinpoint it to that side, possibly towards the front(belt side) of the motor, although it's strangely the loudest(without s-scope) near the oil filter area.

 

Could it be one of the oil pumps?
Lifters?

Something in the sump?  Worth pulling that cover?

Is it time to pull the cam covers?  I need to get the proper tools first.  Anyone have any tips on changing lifters on a 987S?

Jay.

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While I'm working on getting the clips uploaded, I found this video which sounds quite like my car:

https://www.youtube.com/watch?v=cOCZsBIIXNA

 

I also only have about 50 miles after the oil change and lots of idle time.  Running M1 0W40 per the dealer but considering a switch to Edge 5W40 as a trial.

Jay.

Edited by Geflackt

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Changed out the plugs today.  Seemed to have even torque all around.  Plugs all looked even with just a hint of oil.  Found one coil pack having cracks starting, but it's not on the side that seems to have the tapping.  Idle is still a little "nervous", but I didn't disconnect the battery or reset anything.

 

The tapping is still there, though.  No difference after changing the plugs.  I captured a few sound clips and will be posting soon.  It really seems to be around the left side, bank 2.  With a stethoscope I can still only pinpoint it to that side, possibly towards the front(belt side) of the motor, although it's strangely the loudest(without s-scope) near the oil filter area.

 

Could it be one of the oil pumps?

Lifters?

Something in the sump?  Worth pulling that cover?

Is it time to pull the cam covers?  I need to get the proper tools first.  Anyone have any tips on changing lifters on a 987S?

Jay.

 

You cannot remove the cam covers without special tools as the covers also actually hold the cams in as well.  Do a search, there have been DIY's on how to do this and the tooling involved.

 

It could be one or more cam followers (lifter) which has collapsed (they are hydraulic).  Changing them out will require pulling the cams off to get at them.

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You cannot remove the cam covers without special tools as the covers also actually hold the cams in as well.  Do a search, there have been DIY's on how to do this and the tooling involved.

 

 

Yeah, wasn't planning on starting that cam-cover project until I had the tools to hold the cams.  Trying to exhaust all other possibilities before pulling the trigger on the tools and time.  Looks like an interesting project, just not something I wanted to do but will do it if needed.  Spent way too much time already looking at the process.  After doing the plugs today, it looks like the cam covers can be removed in-car.  Is that possible?  It's a little tight, but having it on the lift and panels removed it seems do-able.

Jay.

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You cannot remove the cam covers without special tools as the covers also actually hold the cams in as well.  Do a search, there have been DIY's on how to do this and the tooling involved.

 

 

Yeah, wasn't planning on starting that cam-cover project until I had the tools to hold the cams.  Trying to exhaust all other possibilities before pulling the trigger on the tools and time.  Looks like an interesting project, just not something I wanted to do but will do it if needed.  Spent way too much time already looking at the process.  After doing the plugs today, it looks like the cam covers can be removed in-car.  Is that possible?  It's a little tight, but having it on the lift and panels removed it seems do-able.

Jay.

 

 

The cam covers can come off with the engine still in the car.  It will be tight, but it is doable.

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Didn't solve it yet, but I've done a lot of work(never worked on a Porsche motor before, so it's been a learning experience with some help).  Found the engine internals to be very clean.  I even replaced a side of lifters myself - didn't solve it.  Waiting for one part which I should have this weekend.  Once fixed I'll post a full report of what I did and what solved it.  I'm looking again at chain tensioners at the moment.

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Are chain tensioners something that must be changed?

 

They are a "wear" item, like a clutch or brakes.

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In garage at moment, he has traced to bank 6

He suggests bore scope in and if that looks ok then valve train

I have put a fuel cleaner in and running a tank of shell v-power and must say it's much quieter today. It probably is the bores as has 75k miles on but doing limited mileage/summer car so should be fine for few years I hope then will sell and move on

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All checked and oil changed, instantly car was quieter and on drive home noise has almost gone...long story but car was serviced in July 2014, major including plugs before I bought by garage selling. I contacted garage to find out oil used and they said 10w40 Mobil super semi.. After few emails I advised this wasn't A40 approved and few days later received email to say think they used Mobil 3000 fully.

So not taking chance (cars only done 500 miles since July) decided to have oil and filter change using 5w40 fully A40 approved, after change and running with fuel pump fuse out to turnover, codes cleared and car starts no smoke, runs smoothly and ticking started to die away...fingers crossed that's it but will live in hope.

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Ticking comes back after car has been left idle, car sits in car all week and does very few miles..

Really thinking its a tappet going bad?

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Well, I'll post an update for any new ideas, even though I'm not sure it's solved yet.  I'm in the process of changing out the stock headunit for an Android based unit(rooted and sideloaded - ready to go!).  As a side note, this is the first Porsche I've worked on, but it's been a good learning project.  Many thanks to JFP for the support!

 

Again, this is a 2006 S with 75k miles, not driven much by the previous/original owner in the last year or so.  The tapping starts once the engine has dropped to 680rpm, which is not quite up to full operating temperature.  It's a single tap around the frequency of a cam revolution or valve.  May not start for a minute after hitting 680rpm, goes away by about 900rpm, and may not return for 30-60 seconds.  Seems to be around #6 cylinder and I can also hear it in the first cat on the exhaust using a stethoscope.

 

Here's what I did, roughly in order:

- Replaced oil pressure relief piston and spring

- Changed over to Driven 5w40 oil

- Tested without serpentine belt

- Checked torque on all exhaust bolts

- Changed spark plugs, which looked used but not fouled.

- Changed lifters on the cyl 4-6 side(the side with the noise)

- Took apart intake plenums, found loose vacuum control flap joint and fixed

- Cleaned MAF and throttle body

- Cleaned intake plenums.  The AOS was going bad, but still seemed OK.

- Replaced AOS

- Replaced all 3 chain tensioners(they didn't hold pressure while hot, showed a little wear, but not that far off the testing of new tensioners)

- Dropped the sump.  A little sludge in the bottom, but no pieces in sump or oil filter/housing.

- Added oil pressure sender and gauge.  Oil pressure decent(40lbs at hot idle).

- Scoped the 5 and 6 cylinders and look clean, except top of the piston is a little oil-wet.  Plugs are not fouled.

- Cam deviations before and after work look excellent

- No CEL's

- Can't tell adaptations yet, as it hasn't been driven

- Swapped #5 and #6 coil pack, but have not tested this yet.

 

However, I've not had a chance to really drive it since doing all this work!  Our roads in PA have been bad with weather and pot-holes.  So my next plan is to get out and give it some good miles.  Thinking it could still be an oil gallery issue around the lifters, but I'm running out of ideas.

 

Good thing is I have tricks for a ton of this stuff now.  Locking cams and pulling tensioners is down to a science.  While I'd rather not do lifters again, I don't think it would be that bad.

 

But man, I just want to get out and drive!

Jay.

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Let me know how you get on please very interested as sounds just same as mine, shame you have done everything really as can't pin point which one has sorted

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Geflackt how did you get on and if now sorted what do you think it was...

I have noise both sides so think it could be faulty lifter(s) the noise is worse when cold but soon settles to a barely audible tick with revs when warm, it is getting better as I use car after the oil change to 5w40.

I have checked the plugs on 3,5&6 (also replaced) and they looked fine. I am having terraclean/decarbonising done tomorrow and will see how it goes

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Haven't really done much in the last few weeks.  Just finished with the "infotainment" install and a full-up detail.  Our weather and roads are still too bad to drive out anywhere.  I am looking to get the car out by the weekend for a run, so I'll post back with an update!

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Geflackt, you are not alone and have just detailed essentially the same list of items I checked/replaced in my garage a few years ago based on the exact same symptoms on my '07 Cayman S.  I can appreciate the effort and learning curve you speak of.  I also did one more major thing and pulled the trans to check the DMF for excessive wear (which can make a somewhat similar noise) and found it to be out of spec.  I replaced it to no avail.  If you ever find the exact smoking gun I would love to hear what it is, but here is what I do know:

 

It is certainly related to the oil system flow/pressure conditions as I tried multiple oil weights/brands and 3 different oil filters and they change the nature of the noise.  The biggest change came from removing the LN Engineering spin on oil filter adapter with Napa Gold filter (exact filter LN recommends) and putting the stock filter system back on.  This helped dramatically.  I had also replaced the Sport Chrono stopwatch with a high quality Spek oil pressure gauge and upon putting the stock filter back on picked up more oil pressure across the board.  Following that I cut open the Napa Gold filter and found the filter element to be crushed/collapsed, presumably from over pressurization due to no bypass valve for relief (stock valve is inside the plastic filter housing, so it gets eliminated by LN's kit).  It is not my intent to blame LN whatsoever, you make your choices and accept risks, but my oil pressure data and crushed filter experience convinced me that that adapter kit is not safe and it certainly exacerbated that noise.  The last "tweak" was changing to Castrol 5W-40 which is Porsche A40 (I tried multiple 0W-40, 5W-40, and 5W-50 weight oils, some Porsche A40, some not).  The heavier the oil weight the worse it was, which is contrary to the usual advice of a heavier oil to fix a noisy lifter at cold idle, but then again this noise is always hot idle and never cold idle.

 

I'm not claiming its the best oil ever or that M1 is junk but using that oil with the stock filter essentially solved the problem.  After many thousand miles on rare occasion I hear a tap or two but nothing like it was.  Good luck, I know I pulled my hair out trying to solve it.

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This is a topic that I am experiencing here. I can't contribute much except:

The Porsche mechanic who serviced my car in the past; fixed transmission leak by rebuilding it and changed IMS bearing said these engines hold up well. Two years later, I have the same tapping or ticking or whatever you want to call the noise from the engine. I spoke to Jake Raby today and got a ear full of faults with Porsche engines and a hefty price for a replacement upgraded "tank-like" engine. He seems to know his stuff, but all things have faults unless design and money has no object. My advice is to find a good Porsche mechanic, I mean someone who really loves Porsches and see what they have to say. Then reflect on what it is you expect from and of your car, then decide what to so. Sorry if this does not help, but I am in the same situation as you. Just wanted to share some thoughts.

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