Winterreise

Any help would be very appreciated!

Ahsai

Sound is ~10Hz and it sounds like a valve tappet or scored cylinder. Should also check for a loose spark plug and the cats. You need to jack up the car and use a mechanic's stethoscope to pinpoint the noise better.

Why are you using 15w-50? That's not a Porsche approved oil. Was this sound there before the oil change?

fullthrottle52

I recently had the same tapping. It sounds like a lifter to me. Mine still does it on occasion but the more I drive it the less it happens. You probably have a partially blocked oil feeder hole in the lifter. Once the oil warms up the lifter pumps up and begins to function again. If it sat all winter it can happen. I too would move to a Motul 5 w 40 oil and see what happens.

fpb111

+3 for tappet. I would try 0-40 or even 0-30 for a short time to see if it pumps up quicker.
The oil in m96 engines does more then lubricate it also acts as a hydraulic oil in tappets and chain tensioners among other things.

mhs525

My car made almost the exact same noise after I started it for the first time after it sat for several months through the winter. I was pretty concerned as the noise was new but after the car fully warmed up the noise went way and never returned. I had also just changed the oil. My theory is took some time for the oil to fully lubricate all the engine components. I have been driving the car for about a month with no problems and the noise had not retruned.

I often have a few seconds of chain slap as oil pressure builds. I have read that the chain tensioners are hydraulic and the oil pressure needs to build for the tensioner to work. My cold start chain slap is not the same as your noise.

I use Red Line 0W-40 oil and am very happy with it. I recommend staying with the factory specified oil weights no matter the brand. I think the oil you are using is too thick when cold (on startup) which is why it is rapping so long until your engine starts to get warm

Spokayman

As described above, my understanding of tensioner related chain slap upon startup is that the noise is quite loud immediately and goes away (or nearly so) within a few seconds at the most.
At least that is what I experienced on my '01 3.4L C4.
This noise happened at every first startup of the day and it was worse the longer the car sat between startups.
After the engine had already been run on a given day, subsequent startups did not produce the chain slap, or if so it was so brief that it was nearly indistinguishable from the initial "roar" of startup.

As others have said the noise in the video sounds like a lifter.
I have a 987.1 Cayman 3.4L that produces a similar sound. The noise is intermittent (happens infrequently), is more likely to occur the longer the car sits between uses, and goes away in 2-3 minutes.

I have always used Mobil 0-40 in all my modern-era Porsches.
As others have suggested, try running a thinner weight oil (0-40 or 5-40) and see if the noise changes. You can watch your oil pressure for signs of the oil getting too thin and change to a 5-50 if necessary.

fpb111

On another thread I believe that you mention that you recently bought this car and it had an oil change to Motul 0-40 just before you took possession. Do you know if it sat for long before you bought it? Are you driving it everyday?
My 2003C2 has a tappet that is slow to pump up, sounds like yours, if it sits for a few weeks during the winter. During summer when it is driven almost every day it is quiet.

Flat6 Innovations

Was this car driven this past winter, or stored?

Winterreise

Yes, Jake, the car was purchased by me in December 2014 with 86200 miles on it. I drove it through this last winter, oblivious to the stress of multiple cold starts on the M96. The car had Motul 5W 40 oil in it at that time. Thinking that I was protecting the engine for summer driving, I upped the weight to its current 15 W 50, also Motul. The tapping is more prolonged now, since adding the heavier oil. Today I will change back to Castrol Edge 0W40 and see what happens.

Flat6 Innovations

The rhythm that I hear is NOT a lifter. All the proper constants are in place for a classic cylinder failure. Before you spend a dollar on a lifter job, you better get some trained M96 ears on this one that knows the differences in the sounds and where they are generated from.

The higher visq oil is making it worse for a reason, which is another constant with most cylinder failures.

Approach with great care.

Winterreise

Well, that is reassuring... I will change the oil back down to a zero weight and new filter and I guess we'll just see what happens. My impression of the independent Porsche mechanic that I have been using is that he is quite competent with the M 96 engine. Whatever is happening with my engine would seem to be in the initial stages. Two days ago, I posted on my other thread that he had the car up on a lift, warm and idling. He used a mechanics stethoscope and listened in multiple places on the engine. No obvious source was found. If I have scored one or more of the cylinders there's not much I can do about it. The brutality of the cold temperatures in February does give me concern. I wished that I had been warned in time. What confuses me is the fact that the start up noise that I recorded on video and shared here, virtually disappears when the oil has circulated and warmed slightly. If there was a defect created in the cylinder wall of one or more of them, why would the sound decrescendo and finally go silent? I will change the oil back to an approved (A40) Castrol Edge 0W40 this afternoon keep you all posted.

Pensively,
Bob

Flat6 Innovations

Yes, very initial, thats why the heavier oil aggravated it and made it apparent.

YES THERE IS!!!! Why? Because the first thing that occurs during a cylinder failure is actually a failure of the piston coating, then piston failure, then cylinder failure is collateral damage from that.

We have saved several engines from this in the past when caught early on, before cylinder damage occurs This is a super critical stage of the failure.

If you change the oil and the noise goes away, trust thats only temporary and may give you false hope that the noise is gone for good. When the noise comes back, it'll be too far gone to repair it by swapping/ coating pistons.

This one was properly diagnosed and caught in time to be saved. Time isn't on your side. No noise is a good noise when working with an engine. Please don't drive it to death.

DTMiller

Jake is not often wrong. You have a chance to save your engine.

LexVan

Your Rennlist membership fee just got reimbursed by Jake's free advice. Good luck.

Winterreise

Ok. What would be the definitive method of diagnosis short of dropping the engine and removing the heads? Is there a way to be conclusive without disassembly? Is one way to remove the oil pan cover and scope the cylinders to check for any streaks?