question about possible lifter noise
 

My 01 S developed a misfire several weeks ago. I shut it down and had it flat bedded to my house. It had a miss in cylinder 3. I didn't have time to tend to it and came back to it a week later. When I started it up, it no longer had a misfire-- I cleared the code and it was fine over several on/offs.

However, since that time it has developed a very distinct rpm-dependent tick that, based on my research, seems to fit the description of a stuck/underperforming lifter. Is it possible these two could be related, or that the miss could have created something else that would sound similar?

When was the last time that you change your oil?

It is due. 3k miles. I did read about how older oil could cause the lifter noise.

Is there a recommended additive to help with this? Or just change the oil and see how it goes?

These engines seem to be very hard on oil. I had a similar thing happen last summer, with one lifter that was suddenly loud enough that I thought I had a serious problem. An oil change seemed to cure all its ills. Give it a shot and see. I personally don't trust any of the additives.

Thanks very much. When I first heard the noise I heard large dollar signs. While that's still a possibility, it's encouraging to hear there are a few quick things to try.

Considering the time we spend (waste?) discussing oil/ oil change intervals/ UOA/ filters/ magnets /upgraded lifters/ stuck lifters/ engine rebuild costs .........
If the problem is in fact dirt plugging the tiny orifice in a lifter the chance of flushing it out with fresh oil/Marvel snake oil is very low. Take a few jammed/dirty INA lifters apart,you'll see the problem.
If the problem is dirty oil, you will never get all the sediment out from the nooks and crannies in the engine. Rebuild an M96 and you'll understand. So multiple flushes and oil +filter replacements may help but they may also dislodge debris and unless you have a upgraded full flow filter ,the dislodged dirt may flow onto another vital surface.
Which is why we "we spend (waste?) ....discussing oil/ oil change intervals/ UOA/ filters/ magnets /upgraded lifters/ stuck lifters/ engine rebuild costs ........."

Thanks Gelbster. Something like LN's adapter and the corresponding filters are what you're talking about, right? After seeing your post and reading about them that seems to be a smart path to take.

Spin-on Oil Filter Adapter for MY97-08 Boxster/Cayman/911 - Parts & Upgrades - Products LN Engineering

The down side to the spin-on filters is that it makes it harder to check the filter material, as you need to cut the filter can to get to it. That said, I use a spin on filter.

I think the key is to use a quality oil and change it every 5k or less, especially if you see track time or extended periods of high RPM running. My issue started after a cross-country trip with the engine at 3k+ RPM for about 14 hours each way.

Agreed, Cheap and easy PM - if it isn't too late.

could be lifter. could also be injector or piston slap - all tick. given the misfire condition (tied to fueling and air) i would suggest the injector is your first stop. try swapping injectors and see if your misfire moves.

And bearings start as a tick.....
If you are picking injectors to swap. avoid #4 - you'll see what I mean when you get in there.Removing Bank 2 injector rail is difficult access.
Much easier to use an Engine Ear and poke around.

It COULD be a lot of things. It is easiest to start with the simple and do an oil change, which it sounds like it needs anyway. If you still have noise, then you can get paranoid. I would recommend not getting paranoid too soon. BTDT. :)

If there is one thing that I have learned over the years, it is that you fix what you know is a problem first. It is sometimes surprising how things that you might not think are related actually are.

i agree - simple and principle of occams razor - the most likely culprit is probably the culprit. in this case i would argue that:
(a) injector is as likely or more likely than lifter
(b) swapping injectors is less expensive, and as simple, as oil change (open engine, two bolts, two electrical connectors, swap two injectors)

otherwise, i'd note that oil was changed only 3k ago, so should still be well within useful life. further, an oil change, spin on filter, etc., are preventative maintenance designed to stop problems from happening, not repair, which is designed to fix problems. if a lifter is screwed so bad that the engine is coding, then repair, not prevention, is most likely required.

"(b) swapping injectors is less expensive, and as simple, as oil change (open engine, two bolts, two electrical connectors, swap two injectors)"
Not on Bank 2 !
The Airbox is in the way even if you lower the engine slightly.If you drop it 6"+ O.K.
In theory you unbolt the intake manifold for Bank 2, move it inboard far enough to actually get at and move the entire injector rail. Then fiddle with the clips to remove an injector.Be careful -those clips really fly ! Remember which way around the clips go ! You did buy replacement O ring seals for the tops of the injectors ? Before you put them back ,carefully dig/inspect up in the bowels of the injector rail to make sure bits of decayed seal are not stuck there.
If your injectors are not 4 hole type - maybe upgrade time?
It may also be a good time to replace all the O rings and the filter basket - do a diy flow test and resistance measurement for the coil. Soak the tips(not the entire injector body ) in Techron or similar.Flush with Techron.There are some diy flush/test videos but remember 30 psi max !It is fun to make a test rig .Just be careful with the pressurized fuel.
Like so many things on the M96, it gets complicated fast because of access and deferred maintenance.

his misfire is #3 - more room on passenger side? i agree that stethoscope is probably a good investment.

Agreed -you know your way around the M96. That is why I mutter about Injector #4.
Yes - Steelman Engine Ear - diagnose ,don't flail !
I only participate in the "what's the problem?" questions because it is fun. Makes no sense commercially

IME, misfires are rarely caused by injector issues, but more often ignition related. I have probably seen 100 coils fail for every injector failure. If he was to go swapping anything, I would swap coils. He may have a ton of miles on his plugs and leaking plug tube O rings as well. There is not enough information to draw any conclusions.

But first I would change the oil...

Just my $.02. YMMV.

Agreed but the misfire disappeared in the 1st Post. The problem is ticking. But interestingly, a cracked coil could produce a sort of ticking (if you could hear it over the engine clatter) as it arcd to ground.maybe?

This back and forth is extremely helpful, guys-- thank you!

The engine runs smoothly and evenly now-- no misfire, just the loud tick. I will go get a stethoscope.

I just swapped to a 987 airbox and yes, that side is a PITA. Glad the miss wasn't over there.

TRK, I can't help but feel that there's an impending repair as you suggest, but I am going to do the oil and LN adapter, inspect coils due to the past misfire, and poke around with a listening device.

Is there any reason I should minimize the amount of time that the engine is running with this tick? I figure that a valve stuck open would probably impede a decent idle, wouldn't it? Since it's idling fine I think I'm ok there, but I thought I'd ask.

Oh, 60k service was 6k miles ago--
plugs, tubes, o rings were installed then. coils were inspected then and ok.