jadh

Hello!

I post this thread to have your Porsche owner opinion on my 964 engine noise (valve ticking or tapping ?): Do you think it is normal or not?

Here is some explanations:
It is like valve rocker noise “tick-tick-tick“ but it sounds “tack-tack-tack” on the right engine side. I have tried to locate the noise with a stethoscope but it was unsuccessful.
The noise is more audible during several minutes when engine temperature is increasing.
No noise at cold start during approx first 1 to 2 minutes. Then, the noise begins, and when engine is at service (warm) temperature, the tapping noise is less (to none) audible. The noise follows engine revs but is covered by the engine noise when over 3000rpm.

As I am not English native speaker, I prepared 2 files for you to listen to.

1) noise (tack-tack-tack) present during temperature increase after 2 min from cold start.

2013-8-4 démarrage à froid après 2 min sortie maison.zip

2) engine hot after 45 minutes driving: no tack tack tack… (it seems)

2013-8-4 chaud après roulage 45 minutes.zip

I own my 964 for 5 years and the noise still the same despite annual services and the 30 000km I have done.

Additional information:
- no loss power
- no blue fumes on morning start
- no excessive oil consumption
- Temp & oil pressure ok
- the car is a 1992 C2, with 102000km on it.

Does any of you ever heard about this type of noise? What do you think about it? One of my valves is a bit loose?

Thanks for your reply and excuse my written English that may be imprecise for this description.
Regards

carlskisWP

I'm no expert, but the clack/clack in the first (2 min) file didn't sound like valves or valve train to me, but I did also hear valve ticking and ticking in the 45 min file as well. The clack sounds like something is loose. Maybe as the engine heats and expands what is loose tightens up a bit? When did you last have the valves adjusted? The ticking noise in the 45 min file sounds like my engine and I'm due for a valve adjustment.

Feudal Serf

Sounds to me to be exhaust related. Any loose brackets?

jadh

Thanks for your reply!

My last valves adjustement was 5000km ago. After this no noise during 500km and then the noise came back.
I measured time between 2 clack and the result is twice the engine revolution time. Ie: the same as valves move...
Exhaust pipes brackets loose would lead to "explosion" noise more than a clack? No?

Dick964

Sounds to me like a broken valve spring....

robt964

edited

jadh

Hello Dick 964

Valve spring was my first thinking. All valves spings were checked during my last annual maintenance 5000km ago. An andoscopic cam was used. (see pics attached for example)

Result : no valve spring brocken.



I have got all 12 springs movies

(reminder, noise was present before annual maintenance)

jadh

Hello.

A up for my first post here.

Any other opinion to help me in understanding my ticking noise?

Thanks for your help

doruiacovescu

I also have the same noise. Double checked and did the valve job. Noise is still there. Now when engine is cold i hear something similar to a pen being sharpened. I suspect the chain tensioner as the sharpening noise gets away when engine is hot

FeralComprehension

Given that you took the time to endoscope the valve springs I would assume you also checked to ensure that all the head studs are unbroken? In my (limited!) experience, a small exhaust or combustion leak can sound very similar to a ticking valve...

jadh

Hello and thanks a lot for your reply and your help. Sharing experience will be helpful for me and you I hope.

@doruiacovescu, Is it possible that you record your noise? I am really interested by comparing with your noises and make additional checks on my car.
For information I listened to my noise using a stethoscope. I have checked the distribution chain... nothing remarkable in my case. I may have missed something?

@FeralComprehension, I will check any leak on exhaust pipes. I checked several times my engine leak. No leak at cylinders. Head studs seem to be in perfect conditions.

Do any other of you have any ideas or advices, or noise records to share?

Please add your comments to this thread!

Many thanks

FeralComprehension

A stethoscope can be used to detect an exhaust leak if you remove the metal probe and diaphragm and replace them with a long metal tube. As you get the metal tube closer to the place where the leak is the volume of the 'phut!'* goes up sharply. Use caution.

(*technical description of the sound of an exhaust leak)

jadh

Or using a flame instead of a stethoscope? The leak will blow the flame no?

HiWind

i dont think you can use a flame as the fan is pushing air around thru/underneath the engine ..
interested to hear where this goes ...

vwomar

Any updates to this noise?

I have the same intermittent rattle as in the first sound clip. I think I narrowed it down to left side timing chain area with my stethoscope. I am thinking it may be a tensioner, etc?
Curious as to what you found out?