RT930turbo

From dead cold, if all the noises go away when warm, I wouldn't be as worried about it. The OP noticed his at a drive through, which would lead me to believe he has all the noise even when warm. Most of what i hear on your recording is normal. Albeit I'm on my phone. I'll give it a listen on some good speakers later. The difference to me when you listen to the first two posted, there is a rhythmic "clunk" every revolution. The sewing machine noise, fast clicking, etc is all valve train and injector noise. If you open your oil cap with the car running, and have noticeable positive pressure, then there is most likely a cylinder issue.

I may try and snag a video of a Brand new 958 running at Idle if I can get a chance.

wrinkledpants

I've been building motors my entire life - family owned a motorsports business. I also rebuild and test F16 engines as a weekend job. No big deal - just 50,000-ish HP. Does that make you feel better?






You're the one with a motor that blew at 100K miles that wasn't driver error and wasn't from lack of maintenance. M1 is too thin for this motor. That's not an opinion - it's just math. If a motor needs a 40W minimum, and M1 0W40 is a 30W then I'm not sure how you make the argument this oil is just fine. Plenty of oils out there stay in grade, and with much more anti-wear additives. LN has been posting these same premise in the 996 forums for a long time and with a lot of good info to back it up.

But - you're the expect.

RT930turbo

Done arguing with you, this is stupid. If you think those two engines sound perfectly healthy with no chance of a problem, you're an idiot. I could post pictures of the hanger full of Gulfstreams right outside my door right now, but presumably, we both know comparing turbines to pistons is silly and irrelevant.

I did however build the O-360-A1D in my Mooney, no issues with that build either...

Even if the Mobil is too thin for a high load, high heat environment ( I AGREE WITH THIS !!!) , how is that relevant on an issue directly related to cold starts?

I still find it funny when people hold Porsche engineers to such high standards that they refuse to even recognize there COULD BE a design issue, or high failure rate, yet they argue about engine oils and know better than the engineers.

I'll ask again, how many 4.8's have you even been around, driven, lived with on a daily basis, or otherwise even checked the oil on?

I'm posting here to offer technical advice based on real world experience and research related to the engine at hand.

I 100% grasp the concept and economics of why Mobil 1 is used and recommended. Is it the perfect oil made from unicorn tears? Nope. But it's readily available, and serves these engines just fine in a normal duty cycle.

On a side note, I see why you're called wrinkledpants

I love the internet

endless_corners

I actually think this back and forth has been informative and productive. Even if things have gotten a little frothy — it's really a benefit to the forums to read the impassioned positions of various people sharing information and perspectives they believe in.

I just find it it so illogical from a business perspective that Porsche would have let the next generation engine (4.8 vs 4.5) continue to have a design flaw in a model line that is their main bread and butter. For a company that has been so methodical about grooming their portfolio to monetize sustainably - it makes zero sense to cut corners on a volume platform. The cayenne is a crucial vehicle for them and they had time to sort this engine out.

As an aside what year is your 957 RT?

RT930turbo

It makes no sense to me either! I'ts kind of shocking they would do this on the high volume engines.

I guess the reading can be valuable, hopefully the OP thinks so. I'm not upset with WP, in fact if we were closer I'd invite him to the shop for a beer

wrinkledpants

I happen to think these discussions are healthy. The great thing about perspectives is they can either be absorbed, or ignored. Enough people will read this thread that their own internal biases will lead them into one group or another.

All of my posts were in relation to "'all these 4.8's that are scoring" and "I thought they fixed this after the CS." Turbines and pistons are very different, but bearings and metal surfaces sliding past each other are found in both. Same with bomb proof O-360 or 300 HP IO-550. There are lessons to be learned from all walks of engine building.

I never commented on what the OP's car sounded like. My posts were in response to "all those scored 957's" and "I thought they fixed this with the CS." The 957's I've seen posted on here with images had a much different score pattern than the CS. Most of them failed early in their life, and most were repaired under warranty. The CS has a very specific cause. Cold and mileage augment that. Correlation and causation exists there, and the common recommendation on this forum is not to buy a cold-weather CS. Flat 6 and LN agree with all this. I think this CS scoring issue has given many Cayenne a bit of hypochondria. Confirmation bias is a powerful thing, and we all suffer from it in one form or another.

Cold starts are always loud on a Cayenne because open loop enrichment is happening with the air-pumps running, and the load values are quite high on the motor to get those pre-cats heated up and functioning. Once the air-pumps shut off, things quiet down, and once it' up to operating temp, it's mostly injector noise. If I listen closely at the back of the motor, I can hear a rhythmic dieseling type noise, but it sounds more like the exhaust pulses harmonizing than piston slap. I've heard this on every 4.5/4.8 Porsche V8 I've had contact with. You can easily log these values and watch the load parameters change. This goes above and beyond the usual open loop warmup cycle.

Many 955 and 957 owners have posted videos like above, changed to a different oil, and reported a much quieter ride. A friend of mine did, too. I thought for sure he had a scored cylinder given how loud his motor was, and I don't jump to that conclusion easily. He switched to T6 - nice and quiet. My 450 HP B5 S4 was the same. Loud on M1. Lots of oil consumption, wear numbers quiet high. Switched away - less consumption, quieter motor, were metals better than average. I was getting about 1 qt/1k miles of consumption on the CTT with M1. Wear numbers were much higher than averages. But, I'm in Denver, and will frequently tow 5K lbs up the interstate in 90 degree weather with less air to cool things. So, my motor sees high-load fairly frequently. M1 was not cutting it, and my lead numbers were creeping up damn near 20 PPM. Switched to T6, consumption went way down, motor is more quiet, and wear numbers are below average, despite having twice the miles on the oil. Lead is now 4 PPM.

People are really quick to point the finger at the lubricated part when it fails, rather than insufficient lubrication. This is often what LN and Flat 6 elude to when they talk about oil, specifically M1 0W40. It has very little ZDDP, fuel efficiency requirements have pushed the viscosity numbers lower, and it simply does not stand up to the abuse that a big HP V8 in a heavy SUV puts on it. This is a common complaint about the oil from many forum members from various manufacturers. M1 0W40 was awesome in our 1.8T stock A4. Wear numbers were better than normal, not much consumption, and it seemed happy on that relatively unstressed motor.

You don't need to have turned wrenches to know any of this. Any reasonably intelligent person could draw these conclusions be simply being educated about their maintenance practices.

When I see a healthy motor, like yours, fail catastrophically at higher mileages - I immediately assume maintenance, owner mistake, or lubrication. You are fairly intelligent about operating motors, so that rules out ripping WOT on a cold motor. You've stated the maintenance was impeccable - and I don't doubt that. So, I'm suspect of lubrication. If you had run some other oil on the approval list, I'd be much less suspect of it.

I've been around VAG and PAG motors long enough that I've seen a lot of lubricated parts failures that look to me like a lubrication issue, not a part issue. In the aviation world, we call a spade a spade. In the automotive world, everyone thinks their oil is never the cause, despite a mountain of evidence that says otherwise. Lack of lubrication doesn't mean you're going to see wide-spread evidence throughout the motor. It reveals itself subtly, and often on singular parts here and there.

Evidence M1 0W40 sucks:

- LN Engineering and Flat 6, both highly reputable engine builders, strongly suggest not using it.
- Many UOA from various Porsche motors showing 0W40 being sheared out only 30% into the oil change interval. It's one thing to shear from a 50W down to a 40W - that's still serviceable. But M1 shears from a 40W into a 30W, that's not a serviceable oil for this motor.
- People report a quieter motor after switching to a different oil.
- People report better wear numbers with a different oil, myself included (lead 19 PPM down to 4 PPM for example)
- People think it's normal to have 1 qt/800 mile oil consumption, despite the fact that this is 200 miles away from what Porsche specs is needed for a rebuild. Switch away from 0W40, and consumption decreases dramatically.

Evidence M1 is good
- It's factory fill from Porsche


The CS scoring is a well-known mechanism. Correlation and causation are evident. The 957 failures do not have any real strong correlation to a specific variable, and the causation isn't well understood. Most that I've seen are low-mileage units, which would point to a defect that took time to reveal itself. But, when you have a 100K motor that grinds itself to a halt? And there isn't a strong causation like there is with the CS? And you're running an oil that is known to be substantially less than ideal? I think it's hard to ignore that reality. I posted numbers of the total amount of Porsche V8's running around, compared to the estimate of failures, but that type of relationship wasn't OK with you. Now, you're saying that since M1 is used everywhere in the PAG/VAG world, and motors aren't dying in large numbers, that metric IS somehow ok. You've owned dozens of cars, some of which run M1 0W40. Of those cars you've life cycled, 1 has had a complete failure at a relatively high mileage with no other obvious cause. That one failure was also running M1 0W40. I mean....... you gotta see how this must look when you really step back and remove some of the emotion from the equation.

I honestly have no idea how you're able to rule out with 100% certainty that oil is not the cause. I'm not trying to say that it IS the cause, but your specific case has been the most compelling so far that lubrication could be a cause of engine failure. Good oil won't cure the CS problem, nor would it likely save some of the early failures under warranty. But a healthy motor that only makes it to 100K miles?

wrinkledpants

Out of curiosity, how did you legally build the 360 in your Mooney? Are you an A&P?

Torre

So, here are two ~20 sec recordings of my engine

Cold after 8h in 2 celcius.
http://torre.kuvat.fi/kuvat/Autot/Mobile/IMG_4217.mov

Hot after an hours drive around town
http://torre.kuvat.fi/kuvat/Autot/Mobile/IMG_4219.mov

There is quite some lifter noise(?) but I don't hear that clear "hammering on metal with a tiny hammer" sound that I can hear in OP's video and occasionally on that 2012 Turbo video.

I was thinking of trying out this product, inspired by this thread: http://atomium.eu It's developed in Russia, and originally for the military to allow a vehicle or tank drive to safety even after loss of all oil or oil pressure. It forms a protective microlayer on your cylinder walls that is so slippery that you can even drive short periods with no engine oil at all, without damaging the cylinders. This stuff has became really popular in Eastern-Europe.

wrinkledpants

You are *way* over thinking this. It's almost impossible to diagnose a scored cylinder simply from a cell-phone video.

If you're really nervous about the health of your block, take it in and have someone scope the cylinders, compression, leak down test and get a UOA.

Use a good oil. Have good operating habits. Keep up on maintenance. If, after all this, you're still nervous about it all, I'd really suggest selling the car because life is way too short to stress about something like this. And, Porsche ownership is supposed to be enjoyable, not stressful.

Torre

If only I had a dollar for the times I've been told this in my life I'd be driving a brand new Turbo

I did not even give it a thought until yesterday when I got involved in this thread, not one bit. I might ask them to have peak with the boreskope while changing the plugs when I take it in for its major maintanance in May, but just out of curiosity and thats all I'm gonna do about it.

But the thought of having to buy a new engine for this car is no joke, it's pretty near personal bankrupsy time, if we talk dealership prices at least.

RT930turbo

Great post. I think we were attcking this from way too many angles. While you were zeroing in on the number of 957 failures, I was zeroed in on the fact the OPs car sounds just like the 4.8 failures I've witnessed.

While I agree to some extent that the oil potentially may have played some role in my failure, I am reluctant to agree it was the root cause. I know sometimes lubrication problems don't manifest themselves throughout the entire engine, but I would expect to see at least some wear on parts like camshafts and lifters.

Some background on my specific failure:

Car is truly always inside a heated garage at night, and generally speaking sits outside for 2-3 hours at a time when my wife is at work. She's frequently between 2 different locations, so the car rarely sees a true full cold soak. Not to mention daytime temperatures here are generally not in the sub 0 range.

When servicing her Cayenne before winter, and swapping to the snows, I realized she had misplaced the wheel lock key. (I sent her to a friends shop one day for a leaking tire bead and left the lock out for him.)

As luck would have it our first snow happened 2 days later while I was awaiting a new key.

The first snow of this season happened to coincide with a brutal -15F cold snap this year. Against my recommendation, she drove the cayenne to work on the summer rubber. We have a long, steep driveway and she got it stuck in a drift on the way up.

It sat out there for 2 days in consistent -5 to -15 weather until I was able to plow the snow out of the way and attempt to get it up to the house. In the back of my mind I always thought about the cold weather issues I had read about Cayennes, etc. etc. but like most assumed there were no issues with 4.8's, especially turbos, and with a fresh service.

As soon as I hit the key, I knew it was game over. The consistent slight cold tick that we all describe as normal, grew to a reasonably loud clatter. Not unlike what we hear in the OPs video. Slightly louder, but as you can see from my pics, my destruction is quite severe.

Had it been inside the garage, I am convinced it would still be running today. Maybe that's not the case, but it sure is coincidental.

Could the oil be a contributing factor? Sure. Is it the root cause, I don't believe it is. I had no consumption issues, or any other signs whatsoever.

I run the T6 in my old M73 BMW and my 400HP 951, both cars love it. I will most likely make the switch on the 957 when it's back together.

Just my .02


At the time I was working as an apprentice under my IA towards my A&P. Never finished it, life got in the way and I ended up moving away from the maintenance side of things at work, and more into the Flight Technical side of the operation. Ended up selling the Mooney a few years back, since we were always going to the lake to use the boat and the airplane was collecting dust in the hangar. Still miss it every now and again!

RT930turbo

I agree that engine sounds fine. You are clearly absent the "hammering". I wouldn't be worried at all.

deilenberger

One point on the "hammering" - the frequency sounds too slow to me. If it's a piston banging around it should happen every full revolution. That would mean 15Hz at 900 RPM cold idle. It sounds MUCH slower then that to me. Even if it only made the noise on firing cycles - which would be about 7.5Hz it sounds slower. Thoughts?

BTW - great discussion. A local good-reputation Porsche shop serviced mine before I bought it. They use Amsoil 5W-40 euro forumula. I'll have to get a sample analysed when I change it. I'll be interested in seeing what viscosity it ends up at after use. And I'm thinking of 7,500 mile changes since the Turbo isn't my primary transportation, and 7.5k is likely to be close to a year's use. Amsoil does have A40 Porsche rating.

19psi

What exactly is a 30W or 40W oil? The W stands for Winter and it applies to the first digit.
If there was an issue with the VISCOSITY (30 or 40) of the oil at 210º being too thin, the scoring issue would be happening in hot climates...the complete opposite of what's happening.

So are you saying an oil that's thicker at startup during sub zero temperatures is better for a Cayenne engine?

endless_corners

Wouldnt a thicker oil be better at sticking to metal parts and a thinner oil more likely to drain off when the engine rests?