Mkha

I have a 98 year 996. 148tkm

the engine ticking sound from the right side . sound is when engine is warm and idle .

the sound disappears when the air conditioning switch on because rpm is higher or rev the engine. and when you rev the engine sound does not necessarily return immediately.

the car works perfectly . and I have studied almost everything possible . I pushed with the sound 8tkm and oils changed three times . the filter was not metal debris and the sound is not changed / got worse

here many people have been asking about the same thing. but no one has responded to what was the repair of the problem?

Macster

Off hand it reads like a noisy lifter. That the noise comes on when the engine is warm and goes away with slightly higher RPMs suggests a lifter that needs a bit more oil pressure than the rest to run quietly.

There can be other sources of the noise: Loose plug. Exhaust leak. Noisy injector. What is required is a tech who can listen to the noise and determine its location and from this then have a better sense of what is causing the noise.

If it is a noisy lifter tthe only "fix" for the lifter is to remove the camshaft cover and the cams and replace the lifter. Generally all lifters of the type that is noisy are replaced. That is if the noisy lifter is an exhaust lifter all exhaust lifters on that cylinder bank are replaced.

But if your trusted tech believes just replacing the noisy one is sufficient then that's what you should do.

It is important of course to be sure the noisy lifter is identified. This is one reason why replacing all is sometimes done. Also, the noisy lifter can be due to contamination and the concern is one replaces the noisy lifter but then the other lifters start to make noise.

I've never had to face this but the few times I've come upon engines that have had this problem -- and in one case it was a brand new 2002 996 -- the SOP was to replace all of the lifters not just the noisy one. The labor cost is the same, the parts cost goes up though but not as much as the labor cost would be to have to repeat the process if after some time another lifter got noisy.

Regardless, you need an experienced Porsche tech though to make the actual diagnosis.

RRTEC

My car did this too. I posted videos of it on YouTube. Sea foam in the oil fixed my issue. Although I have since ordered new lifters while I have my engine out for other repairs.

Mkha

did you use engine threatment or cleaner?

Schnell Gelb

Why guess and throw snake oil at it? Just diagnose it per Macster. Or use an Engine Ear to pinpoint the location of the ticking noise.Search this Forum for "ticking". Often an expensive outcome if not diagnosed and addressed promptly.The good news if it is lifters, the generics have dropped a lot in price recently.

Macster

The problem is unlikely to be "cured" by a dose of Sea Foam or any oil treatment. Oil up to temperature is quite a powerful detergent and its flow through the engine and particularly through the lifter hardware is very violent. Besides the problem is not from sludge or vanish.

In zero lash adjuster there is a small check valve (ball backed by a spring) that oil under pressure causes the ball to lift off its seat and let the oil enter the zero lash lifter when the lifter is not under any pressure from opening the valve.

But when the zero lash lifter starts to push down on the valve stem and open the valve at some point the pressure in the zero lash adjuster increases to the point its pressure is greater than the oil pressure being fed to the zero lash adjuster and thus would force oil out and the lifter would collapse were the ball valve to remain open.

However, at some point the increase in oil pressure in the zero lash adjuster along with the spring behind the ball causes the ball to close and seal the oil in the zero lash lifter.

Every time the lifter is pushed down to open the valve the zero lift adjuster is recharged with pressurized oil.

This ball valve sealing and the very tight clearance of the two sliding parts of the zero lash adjuster which acts as a seal is so good on my desk I have one that is clean of any oil and yet the zero lash adjuster still seals even with just air in the zero lash adjuster.

A zero lash adjuster is an amazing piece of hardware.

What can happen is a tiny piece of metal debris gets caught in this ball valve and this ball doesn't seal properly and lets some oil pressure bleed out as the valve. It is a tiny leak and this can explain why the lifter quiets down with more RPM. It is possible the debris can mar the sealing surface of the seat to which the ball seals against and even if the debris works loose the leak remains.

In more severe cases the spring fails and the ball has little to no force holding it in place. In this case the lifter would make noise even at higher RPMs and maybe make noise all the way to redline.

Anytime you add something to the oil you risk thinning the oil and having other critical bearing surfaces compromised by oil that is too thin to properly keep the bearing surfaces separated under load. There is just a thousandths of an inch or so of an oil film between the main (or rod) journals and their respective bearing shells. This is not the place to have thin oil in some half baked attempt to quiet a noisy lifter.

RRTEC

If you are interested I posted before and after videos on YouTube. The sea foam must have loosened up the stuck/lazy lifter. I don't buy into snake oil, but I do "flush" before oil changes with seafoam for 300 miles. Been doing this for years..

RRTEC

Here is my thread. There was lots of fear mongering in it but the seafoam stopped the ticking for me.. People were saying bore score etc but I am staring at all my cyl right now with my heads off and they look new...

https://rennlist.com/forums/996-foru...gine-tick.html

wildbilly32

RR: Great news on the "no scoring.." One question: why do you have your heads off? Just curious.

RRTEC

i ended up with intermix due to a crack on the drivers side head.

wildbilly32

RR: Dang! Too bad about the cracks. Thanks for the thoughts on lifter noise. The comparison sound recordings were remarkable.

Mkha

Today i take the video this sound. I described the 4 cylinders 5 and 6, an endoscope and This is the only scratch what I found It was a 6 cylinder. I think it is rather small, but does this mean that the cylinder is ruined?

AWDGuy

yeah, that's scored but not too bad.

car sounds like mine did, knocking went away once it was reved....

I wouldn't be tearing it down based on that small score though.

How's oil consumption? Smoke on start up?

Mkha

does not consume oil. sometimes starting from cold smoke, but I understand that it is such a feature in these. Should I still remove the oil pan and check even I've never had any metal in oil filter?

Mkha

I took the cylinder heads off. on the side of the tapping sound had belonged to one of the valve lifter are ​​​​loose and broken. cylinders look good, but is this piston clearance ok? Piston slap? appears to be too big because the piston bobs. But every cylinder has the same.

https://m.youtube.com/watch?v=zfFtSwxqi0k