Clicking sound when idle

Hi all, Can anyone comment on whether this sound is normal? http://www.youtube.com/watch?v=LY10k6O6-gQ Thanks!

No, not normal for sure. Best case a noisy lifter. Worst case a scored cylinder To diagnose, use a mechanic's stethoscope and borescope the cylinders to check for bore scoring. Does it go away if you rev it a little bit?

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I think it's only there after some hard driving. I did a few mountain runs just now and when it was very hot, the sound was there. But now the car has calmed down a bit and it seems to be absent.

How long and how many miles on the current oil and what kind of oil? I would suggest an oil and oil filter change first. If it's not consistent during idle, probably it's not bore scoring. Also, how is the oil pressure? Above 1.5 bar at idle?

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Oil change done two days ago. Might have started around the same time, hmm. I used to be on Mobil 1 5W40, am on Castrol 0W40 now. Nothing bad found in old oil or filter. [edit] can oil level be an issue? Exactly 8L went in, cold it's exactly in the middle of the gauge/dipstick, very hot it's maybe 2 bars away from max.

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Those seem fine assuming the Castrol 0w40 has the Porsche A40 spec. Maybe just keep an eye on it and switch back to the previous oil and see if that changes anything. Your oil level is fine but how is the hot oil pressure at idle?

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Ah sorry forgot to answer - around 5 at cold, around 3 warm and around 1.5 or 1 when hot.

"1 when hot" is problematic (assuming the gauge is correct). Did you notice the actual pressure when the clicking happened? If the oil pressure is truly at 1bar, that could be your problem. How's the coolant temp and what year is your car?

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Coolant sits at around 90ish though higher under hard driving. I haven't linked the pressure to the clicking - I will look at that. Is it possible the oil is thinning out too much? Ambient temperature in the mid- to high 30s (Celsius, so 95-100 ish F).

I'm not familiar with Castrol 0w40 but if it's Porsche A40 spec, it should be fine.

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Definitely had A40 on it so I figured it should be okay. I'm going to go try another mountain drive and watch the pressure. Right now I let the car sit for about an hour, temperature gauge is at 82, pressure at 1.8 bar, no clicking.

Okay, so an update. I can't seem to find a reason for the clicking, it seems to come and go. - starting the car - it tends to happen quite frequently. goes away after a minute or so (this is with a hot car) - running the engine very hot - did a mountain climb, coolant is up to 100 degrees, pressure around 0.9 bar when idle. no clicking (?!) - during the mountain climb I'm pretty sure I heard the clicking as I was climbing (I think it echoed from the metal railings). Pressure was around 3bar then, engine running probably at around 3-4,000 rpm. Any ideas? Is it an imminent IMS failure? Heh.

Do you remember if your oil pressure was similar before the oil change or this kind of low oil pressure only happened after the oil change? 0.9bar at idle and 3bar at 3-4k rpm seems a bit low to me but maybe not for 0w-40 castrol. I'll let others chime in. Any chance you dropped a piece of oil bottle foil into the oil filler tube?

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Had a shop do the change (live in an apartment building so can't change oil myself ...), but I have confidence in their work so doubt it was aluminium foil. I'm trying to remember what pressure was at before. I'm almost tempted to say it was a little bit higher, but I wouldn't bet my house on it.

I'm running the Castrol also and I get 1 bar at hot idle, I'm changing to millers nanodrive cfs 10w50 next week as Hartech recommend it , hopefully this will bring my pressure up a bit , my car runs fine though, I get a little bit of lifter noise for a second on first cold start after being stood for a week or so but then fine, will let you know if I get improved hot idle pressure with he Millers!

if that was my car, I'd be getting under there and taking off the sump plate and checking cylinders 456 for scoring

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Hmm. But if it was scored, it would be consistently present, right? I found this video of some guy with a scored cylinder - it sounds more low pitched, almost like a thudding sound. Mine seems like a high pitched metal'ish sound, and it's intermittent - it comes and goes. (I'm obviously trying to stay optimistic here because a scored cylinder would seem to me to mean a rebuild, which isn't really something I'm looking at right now)

Already been said, but here it is again. Find a shop with a engine stethoscope and a guy who knows how to use it on a 911. Get the car hot, and take it there. Let the diagnosing narrow it down some. It sounds internal to the engine to me, could be lifter, scored jug, rod journal. Plenty of possibles. See if you can get an indication of the tempo being every rev, or once per two revs which would relate to valve train.

I recall the general rule of thumb for these engines being 1 bar hot oil pressure per 1000 revs. So, at idle it should be about 1 bar, 3k should be 3 bar. I run the same oil now, and my hot oil pressure at 3k is ~3.6 bar. What's your coolant temp reading when you are running it hard?

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I've gotten the coolant up to about 100C (~210F). At that point, I'm reading ~3-3.5bar at around 3K, so similar to yours (a little bit hard to tell since it's an uphill climb). At idle with oil that hot, I will hover at around 1bar, maybe 0.9. On the highway cruising in 5th (Tip) at 3K rpm I'm sitting at around 3 bars, coolant at ~85-90C (~190F).

If you look at my thread on center rad and 160F thermo, you'll see my hot idle pressure is a bit higher. This is due in part to keeping the engine a bit cooler. https://rennlist.com/forums/996-foru...with-pics.html But, I don't think this is oil related, no matter how much you want it to be that. If your pressure is about 1 bar per 1000 revs, I think you're getting enough lube where it's needed. I think this is a deeper problem. Your oil is rated at 13.5cSt @ 100C which is pretty darn good. I"m actually using the 5W-40 Edge OE which has the highest rating of 13.9, but yours should be fine. The VI of your oil is 169, and the OE is 174, so they are comparable, given that your winter weight is pretty much immaterial in this case. I can't read the Czech Nanodrive website to compare the values, so I can't help you there, except I doubt this is oil related.

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Doh, fair enough. Just sent an email to my indy with my video, let's see what he says. Probably will go in and have him look around the car. That said, I googled around and 996 clicking seems to be a very common subject - quite a number of people have had it with varying solutions from "I just left it like that" to "I rebuilt half of the engine." Heh.

Leakdown test with at least 80PSI in the jugs might be useful. It would have to be done hot which is a pain in the butt. A good mechanic can run the piston up and down in the bore while the leak tester is hooked up and maybe determine scoring, or maybe not. Will not generally help with a collapsed lifter as the valve will still close fully. A hot running comp test may help with valve train issues. Also will need a borescope to look in there at the bores.

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yeah, I get it. ...but hate to say it, I'm 99% sure that's a scored cylinder. engine sounds like mine when I had scored cyl 4 & 6. the knocking noise also went away above 2k rpm for me.

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What did you have to do? Replace the cylinder block? [edit] I guess the only thing I'm optimistically sceptical about is this - with a scored cylinder, shouldn't I have some consistency? In your case, you say the noise went away above 2K - but was it constantly present below that? In my case, for example, I start the engine, it clicks for a few seconds, then I hear it fade away, and the rpms don't drastically change. I'll video the next engine start to give an idea.

I went with LN engineering and their nickies pckg. rebuild it myself.

Okay, I spoke with my indy. In his opinion, first, check the cylinders for scoring. If no scoring is present, he's strongly advising to switch to a different/better oil. His strong recommendation at the moment is a Japanese local manufacturer's 10W40 called A.S.H. "FSE Racing" type oil, which is "100% ester, no polymers." He goes on to say that using that oil in a Cayenne, after a year / 10K kms, the oil that came out of the car wasn't even dark - it was the same original golden colour as what he put in. I'm not sure I'm convinced about using an unknown brand (even if he swears by it), but I am indeed wondering whether this ester snake oil thing and 10W40 is a smart idea or not. Google does seem to suggest that ester is present in M1 oils, for what it's worth.

Get it scoped before anything else. Remove sump plate and youll have acccess to see the cylinder walls. You may need ot turn the motor over by hand or something to move the piston to see the thrust side of the cylinder wall.

here is my bank 2 (cyl 4 5 6) 20150309_223405_zpsu8kyrood.jpg bank 1 20150309_223426_zpsrrqkopia.jpg

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If this is true, my car is not part of the rule. I watched Bar last night on drive home. It was generally 2X my revs. At 1000 it was at 2, at 2000 it was at 4. Interesting, no?

To me it sounds like a lifter. since lifters are injected with oil the sound can come and go.i would try switching to a different oil although the oil inside the lifters usually doesn't change very easily.

So the current situation is like this. * On start, the clicking sound is present for a few revolutions, appriximately 3-4 seconds at most. * Then it goes away and cannot be heard. * I haven't driven the car hard lately so I can't seem to replicate the sound anymore. I'm travelling for a few weeks from tomorrow and when I'm back, hopefully the heat will subside, I think I'm going to give another mountain run a go at that point and see if it still clicks. As a complete M96 n00b, I may be wrong about this, but I guess we will see?

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That's absolutely fascinating. The rule is generally for min hot oil pressure. Maybe your gauge or sender needs calibration. Or you are running 50wt oil, and not getting it fully warm. Or you are just plain special. I looked it up once long ago, and 'rule of thumb' really isn't something you want me to defend, is it?

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Mine clicks a tiny bit on starting after overnight. It's much more quiet than yours though. What's my point? Guess I don't have one. But these cars all seem to click. Hope it is all good for you.

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Running 10-40. I went back and searched a bit. Saw lots of post that had their bar running in the same zones, so not concerned about it. Just thought it was interesting.

Just a thought. Could oil level be an issue? They put in a single 8L container. Oil level shows at about half when cold. Should I add a half quart before changing back to Mobil 1?

youre at half on the digital guage?

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Cold, yes. Hard drive, it tends to go up to about 80%. Too low?

yes, should be full, even when cold.

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Well, I'm a turd then I'll go get 1L tomorrow, drop in about half and see how that goes. Maybe I'm just being a complete idiot about the whole thing.

Im not convinced that will fix your issue. Did you get the cylinders borescoped?

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Not yet. Was away on a trip for a few weeks, so didn't get a chance... going to try to schedule that in the next few weeks (rough travel schedule, sadly). That said, I'm still finding it odd that it will only click once in a blue moon. Like today, it was totally fine, until I got home, where it clicked in the garage for a bit. But not during the day, not on cold start, not on warm starts during the day and so on. Very odd.

If it goes away it's a lifter I would say, if the bore was scored it would tap all the time as once the clearance between piston skirt and bore goes over spec the piston can slap around in the bore when it goes up and down and the thrust switches from side to side on the piston, also there is a flat portion of the head that is very close to the piston crown and once the piston is allowed to **** over to one side more than normal the piston protrudes slightly out of the bore and touches the head also causing a tapping noise, but borescope would be a prudent move to check!

My '99 w/83K miles had some "lifter" noise upon cold start. The cause was diagnosed to a "lazy" chain tensioner (timing to IMS), which was then replaced...problem solved. (Boy, it sure sounded like a bad lifter though.) relinuca

An exhaust leak can also "tick" - in fact, it can sound exactly like a lifter tick depending on the location and size of the hole. Not saying this IS an exhaust leak, but there are other things besides horribly scored bores that can make a car tick...

i had the same thing after a harder run yesterday. I pulled in the garage and heard it. I turned off the car and checked the oil. it was a little low, so i put another quart in it but it still ticked. i let it cool down overnight. I restarted it once when i got up and still had some ticking but went away. I came out 30 minutes later and it went away. I vote a stuck lifter. After my 40 minute drive to work, it is still quiet. I was a bit worried.

Could it be water pump?

Ah the joys of P-car ownership. So here's the current status. I've not done a cylinder check yet; I added about 0.6 quarts of the same Castrol oil as the 8 quart fill I did before. I haven't heard any clicking in weeks now, with the occasional exception on startup, where it'll click for a few cycles (let's say, maybe 2-3 seconds), and that's all. So I don't know if it's fixed or not, but it doesn't seem to be recurring. Instead, I got white smoke now! Will post this as a new thread though and keep this one here updated if I have any further developments on the clicking.

Yea, post some images or video of the car producing the white smoke. Hope you find a solution!

Just another data point. I've been running Castrol Edge 5w40 for a few years now. The engine does seem to be noticeably quieter than when running Mobile 1. However on 2 occasions now my low-oil-pressure light came on while idling to the pits after a hard track session. The gauge was showing about 1 bar at the time (or slightly lower I'm not quite sure). The engine was ticking quite loudly at the time which didn't make me happy. No issues since then (about a month ago). I've stopped doing track days in the meantime. But I'm starting to wonder if I should be running a heavier oil.

Had same noise in my 04. Bad news it was a 2 scored cylinders. Well into a rebuild for 12500.00. I also had some white smoke on start up.