Byprodriver

Clean test & reinstall chain tensioner.

Zylinderkopfdichtung

Was there ever any resolution on this issue? I couldn't quite make out the noise to begin with, but I'm chasing my own noise issues and trying to cover all the bases.

paradigm79

No not yet. I simply haven't had time to work on it lately. I will be inspecting/cleaning/replacing chain tensioners soon. If that's doesn't work I will be removing the cam covers next to have a look around. I'll post again afterwards.

Zylinderkopfdichtung

Copy - thanks. FWIW, here's my "what the hell noise is this" thread: Clicking M97 with only 7300 miles - Help needed!

paradigm79

I finally got the time and parts all on hand to go check all 3 tensioners and replace them if needed. Is it necessary to lock the cams on a 3 chain motor if only removing one tensioner at a time? I have read mixed things on this topic but I do have a cam lock tool on hand if I really need it...just more work of course. And what exactly do you consider "testing" a chain tensioner while out of the car? Just submerging it in clean oil, pump it up, and see if it becomes incompressible? I'm leaning towards just replacing rather than testing just to be done with it.

Macster

Replacing the camchain tensioners is a pretty drastic step without some clear indication this is needed.

However, I'm not at the car, the car is not mine, and I'm not you, but I'm sure you'll do what's best for you.

I can't answer your question about locking the cams down. You need to know, that's for sure.

One might assume it needs to be done and do it, just to be safe, unless this locking down action interferes with the tensioner R&R.

Which to me puts the burden back on your shoulders of you having to know for sure whether it needs to be done.

As for testing the old tensioners, or even the new ones, the tensioners -- to state the obvious -- have to hold oil pressure under all operating conditions and there's no way I can think of you can easily subject these tensioners to real world conditions on any test bench you have access to.

Thus my WAG would be if you are there, if you have gone to the trouble to get at the tensioners they should be replaced, with new ones.

Not having access to the low-level steps involved in a tensioner R&R I can only guess, but the new tensioners might want to be submerged in oil and pumped up or somehow filled with oil to prevent the possibility of an air bubble forming in the tensionerthat might cause the tensioner to not properly tension a cam chain for a while.

I mean I think the last thing you want to hear after going through the trouble to replace the tensioners is the same noise even if it only proves to be temporary. The problem is you might give up and go back in the engine when all is needed is some more run time.

But there is still a risk: the tensioner runs sans a proper charge of oil and it suffers some degradation which hastens its demise and you are back at the engine again doing this for the 2nd time.

In replacing hydraulic valve lifters I would do this to pump the lifters up and at some level at least confirm the lifter held oil, that its check valves were functioning.

Of course, just to stress this, you want to be *darn* sure you have the proper replacement tensioners.

Porsche dealer parts managers tell me it is vital that parts -- in this case the tensioners and other parts required for this job, like the non-reusable camshaft cover bolts, or supplies (like camshaft cover sealant) -- are looked up based on the car's VIN and by someone who has an up-to-date parts number/VIN reference handy to consult.

This is not the time to try if some pseudo-randomly selected tensioner that some parts house had laying around works.

You want to stack the odds in your favor as much as you can that the job will be successful.

Tensioner replacement may not eliminate the noise, though I hope it does.

Whether it does or not, though at least you want to avoid doing any harm to the engine. IOWs, the engine (and you) may not be any better off after this work, but the engine (and you) do not want to be any worse off after this work.

Best of luck!

Sincerely,

Macster.

paradigm79

Not too drastic really, considering the symptoms fit and the spring debris I found is of the size typical of a check valve which the tensioners have. And all the pros have no idea what the noise is and all they want to do is tear into it at my expense. 2 hours of their labor poking around eats up the cost of 3 new tensioners.

Obviously short of any definitive data its best to take the safest route and lock the cams down, which is why I got a lock. Just hoping that someone out there may know for sure and save me the trouble but its really not that hard. I think you might be thinking of an older 5 chain motor. Mine is a variocam plus 3 chain motor and therefore the cam covers don't have to be removed.

paradigm79

Well, pulled out the 1-3 tensioner and found a ton more spring debris and the piston was scored pretty far up making it appear the tensioner had traveled close to its limits. Pretty confident I had found the source of the problem, but nope. Installed a new one and a new IMS tensioner while I was in there and the sound came right back. I also cut open the 1-3 tensioner and pulled out the check valve cartridge. It does not appear that the check valve inside uses a helper spring in this design, just gravity and the reverse flow of oil to hold the ball against its seat. So again, where did that spring debris come from?

Still need to pull the 4-6 tensioner and have a look. If that turns out to solve the problem, it will be a mystery to me how or where that debris I found came from.

Macster

Just a thought... The tensioner may have gone bad not due to some inherent problem with the tensioner, but due to an oil supply problem to that tensioner.

Whenever possible the oil line to the tensioner wants to be checked for any blockage that restricts oil flow.

After assembling and firing up for the 1st time a pick up truck engine I had a noisy lifter in the engine and I traced the noisy lifter to it getting insufficient oil. The reason was an oil galley plug that the engine machine shop has driven into the galley was blocking oil flow/pressure to the last lifter oil feed hole.

I made two mistakes. The 1st was I should have removed all water and galley plugs to make sure none could have been driven into the water jacket or oil galley/passages.

The 2nd was when I got the block back I didn't bother using my oil galley cleaning system -- a nice rifle/gun cleaning kit -- to ensure all oil passages were free of anything that could interfere with oil flow or pressure.

Sincerely,

Macster.

paradigm79

I agree on the oil supply comment, especially since it does not appear that the spring bits came from inside the tensioner. More debris could be blocking the flow or whatever it came from is now leaking flow/pressure and starving the tensioner or possibly something else like the vane cell adjuster and the noise is intermittent valve lash and not chain noise, etc.

No HTwo O

Paradigm, dude, regardless, you have some mad DIY skills Good for you. I'm only able to gas, wash & go. I don't even re-fill my washer fluid for fear of putting in the wrong place.

tikicaca

Do you get any solution for this issue? I've got the same tapping noise in my 65K miles 986 boxster It can be only heard in garage and on idle.. Till now I haven't got any idea...

paradigm79

No unfortunately not, but I'm still working on it. It is very difficult to pinpoint where the sound is coming from, many people have tried and even using a stethoscope. It sounded as it maybe was more on Bank 1 than 2, so I jumped in and tore the heads down to the valve springs. Opened up the vane cell adjuster, inspected all the lifters, blew out all the oil passages, etc, etc, etc. Found nothing except 3 weak and partially collapsed intake lifters. Replaced those and put it all back together. (All this work was done while the engine was still in the car for anyone that wants to try it.) This did nothing and the sound remains. Working on my next plan, which probably mean removing the transmission again to check for crankshaft end play and inspect the clutch. Got to figure out why pushing the clutch in changes or stops the sound most the time.

tikicaca

I'm thinking is this idle tapping sound is not coming from gearbox... It can be heard after the engine is pretty warm, so also the gearbox oil is getting thinner
Despite this idle tapping sound, which can be mostly heard from rear and underneath the body, I've got also clattering noise in range of 2000-3000rpm. It can be heard on video from my car below. I have heard that You also got similar noise on one from early videos posted here. Is this noise is normal? I'm just new in this cars and engines.

paradigm79

It may not be the gearbox in your case or mine. As I've said, in my case its been very difficult to tell for everyone who has tried (dealership mechanics, independent porsche mechanics, gearhead friends, etc. etc) and that's why I opened up the motor and had a look around. I think its possible the noise is from inside the engine, but the root cause is in the gearbox.

When an engine is idling there is not a lot of load forcing everything tight in one general direction, and all the small gaps between moving parts may jiggle around and knock into each other. Specifically, as all the parts rotate in one single direction on a large scale, they actually accelerate and decelerate over and over again with each power pulse. The "slop" between each part allows them to move independently and if some are moving backwards while others are moving forwards it may cause enough of a "catch" that the timing chain goes slack momentarily and then snaps back tight again. It could also maybe be the teeth on the clutch disc that are worn out and rattling back and forth on the transmission input shaft splines. This is all speculation, but in theory it could explain it.

I listened to your video and I hear the noise you are talking about but I'm not sure what it is. I kind of think its resonance in the intake.