Tapping noise at idle query

I've noticed quite a few threads regarding an intermittent tapping at idle, my own car does this once it's been running for 10/15mins, it's is intermittent but does it more often than not. Now a good friend of mine has just bought a 996 and the tapping noise at idle is identical to mine. Reading some forums this is the end as its bore score and there's nothing else it can possibly be, I'm not sure if I believe this as there seems to be a fair few 3.4's do this so can't all be done. I do know the 3.4 is less prone to the bore score but still this is the answer on some forums. Ticking/tapping from idle engine is done. Mines is in bank 2, as is the other car I mention here. Could the chain tensioner that sits on the top and is difficult to get to that could cause this noise at all.

Don't think you should worry yet these noises can be caused by noisy tapers or timing chain, my first coarse of action would be to have a bore scope check you can only guess until this check is done. There are a lot of guys on here with more Experience then me so you should get a lot of good advice. IN THE MEANTIME DONT PANIC Steve

Post a sound clip please .. or if not take one and mail it to me and i'll post it .. [email removed] A ticking or tapping noise is usually a cam follower ( Tappet ) .. either cold or hot . Bore score is a much deeper tone and more akin to a knock .. to actually have this noise means its got severe damage to the bores as the noise is the piston slapping from side to side . It will also increase with RPM where as a tappet will normally go quiet . You would normally have excessive oil consumption and smoking should this be the case . In short .. it's pretty unlikely that both you and your friend both have this . Tappets tapping is not uncommon .

Cheers DeMort, your input is always appreciated. Just sent them to you direct as I couldn't get it to post here.

On my cars with hydraulic valve lifters, I always lob a tin of Wynn's Hydraulic Valve Lifter Treatment in the oil. It's great stuff for resolving this sort of issue. My 3.4 starts up quietly and has no tapping or knocking with a tin of this in Millers 10W50 Nanotech CFS NT+.

Sound clip of the noise .. https://youtu.be/cxx3-x2bbt4

Thanks De Mort, I asked him to send over directly to you as I couldn't get it to email at all. What's your thoughts on the sound, as I say mines sound similar and I've had no issues apart from the annoying noise.

I've answered via email as i was already there .. as mentioned you are welcome to copy paste it here if you wish . EDIT .. aghh .. theres 2 of you ! Ok ill copy paste here in a min . EDIT ... My Reply .. Always happy to help out . You need to upload videos to YouTube then post a link .. the forum cant handle files like this I'm afraid . The first few seconds of the video sound like the correct noise .. once behind the wheel it gets a bit muffled and sounds deeper .. The noise goes as soon as you rev the car .. once back at idle it takes a few seconds for the noise to start again .. this is consistent with something oil fed .. it takes a while for the pressure to drop enough so that there is more play and a noise basically . This is consistent with a tappet sticking .. tensioner noise tends to be from a cold start and only lasts a few seconds . I'm unsure of your level of knowledge here .. you may well understand this completely and if so i apologise but the basics if not .. Think of two buckets with one inside of the other .. oil pressure in between will push the two apart .. if enough pressure then it takes up the clearance between the valve and the camshaft .. If a slight blockage or a sticking of the buckets it cant press as much or it cant refill as quick as it needs to .. this would give a small clearance between the cam and valve which will in turn cause a tapping noise . It doesn't really cause any damage but over time it will slowly get worse . For us guys .. its a bit hard to nail down exactly which tappet needs changing .. we can just change the ones we think or feel wrong on stripping but as a general rule of thumb most garages would change the entire bank .. as thats not cheap then most people tend to live with this unless it gets really bad . For you .. i would tend to say just keep an eye on it .. i would not advise replacing anything at this point . I've posted the video without my comments as I'm keen for others to say what they think .. after all .. i can only say what i feel from a video . You are welcome to copy paste this into your forum thread if you wish though . You have what sounds like either a slight misfire or its the exhaust being a bit loud .. i would need to see the car to go further there .. you also have a slight whine .. for me i would be removing the air box , the drive belt and spinning the pulleys one at a time just to confirm they are all ok .. water pump being the main one to check .. give it a wiggle for play .. there should be none . iain.

Excellent De Mort, I fully understand what you mean regarding the tappets. So my original school of thought being chain tensioner has nothing to do with the idle knock. The dodgy tappet does make perfect sense, rattle comes on when engine oil heats up dropping the oil pressure bringing the knock on. I'll need to have a look at the wynns lifter additive for my own one. I've put up with knock/tapping for a few years and wasn't overly concerned just couldn't believe how similar the 2 different cars sounded with the same idle knock.

2 years kind confirms it .. bore score goes from bad to worse far sooner if its knocking .. it's also more unusual on a 996 . EDIT I'll just add that you have the early type 996 so the cam chain tensioner is also something to consider .. these don't tend to make a tapping noise though .. more rough running issues ... which does lead me back to the possible misfire i thought i heard . A quick check via drive links on a tester at your Indy the next time its in for work would help to confirm these are working ok .

I like that, turn the radio up. Luckily the exhaust on mine drowns out every noise near enough. I was just curious at why so much of these engine make this ticking noise. As YPVS, mentions would the lifter treatment be a possible option, I've never given that a thought before. I'm using Millers 10/50 nanodrive oil just now

It worked for me in my 996 and 2 former high mileage Beemers. At £10-15 a tin, what's to lose? I found the 10w50 a bit thick on cold startups and had tapping for a bit after switching to Millers CFS NT+, so popped a can of this in the oil and it's silent now.

Mine has been like that for 3 years and its never changed so doesn't bother me now.

...afternoon all and pleased that you are back in the fold Iain ( you legend :worship: ) Now many regular readers will know that I have banged on about my chocolate 996 3.6 shitting itself a few years ago leading to an extensive rebuild. In my garage ... Concrete floor and walls my engine when hot mine sounds similarly noisey (start of video) however I was concerned thus took it to Porsche specialist Williams Crawford whom had their engine builder and workshop foreman out to listen , poke around, crawl on the floor etc and their conclusion was it sounded perfectly normal to their ears...they then serviced it and of course it sounded exactly the same following a service... I don't worry now as this check plus Baz Hart stating that some care are noiser than others and Iain hinting if I have understood him that this is a Porsche 996 pecadillo !

Bless you young man . These cars do make noises and they are not young anymore .. I try to explain what i think but also hold people's hands a bit ... noises can be very worrying especially when you read the forum messages of what can go wrong .. It's the same as seeking online medical advice though .. it's always a brain hemorrhage you have !! If EVER in any doubt then get your local Indy to have a listen .. you can even send them a sound clip .. we get them at work asking for advice .. it's always freely given . Trust me when i say if i hear a video clip of a noise i don't like then i make it plainly obvious .. i have in the past told one guy to not start the car and get it recovered as i was that worried .. I was wrong but i would do the same again in a heartbeat . I had to google peccadillo