e3photo

Great attitude Rob, and it sounds like you will end up with an awesome car.

Looking forward to the progress reports.


Emerald

Petza914

Sean, start your small fund for future Silverado repair now. I'm not saying the GM products aren't good and have low mainteance - they do and I have a GM pickup myself, but they're different vehicles than our Porsches - designed differently, used differently, driven quite differently, and not really all that special.. In the next 3-4 years or 120,000 miles, whichever comes first, you can expect to replace your water pump, fuel pump (in the tank - bed off for access), fuel gauge sending unit, HVAC control unit, steering rack, tie rods, and a few other things.

Flat6 Innovations

Post- Mortem complete. This engine had several issues that were compounding.

The classic 997S cylinder bore wear was very evident and looks like this car was operated in a cold climate in the past, or at least was driven in the near zero temps that we had here in our area in January. The wear is consistent with the 997S engines that we see from the north east, mid west and Canada. This isn't S engine specific, because standard Carreras see the same issue, but not so consistently.

This pic tells us that we are losing a rod bearing on this cylinder. The shiny spot on the piston crown is from that piston hitting the head due to a loss of bearing material. We knew what lurked deeper. Note the bore wear at the bottom of the cylinder. Classic.



Another classic cylinder wear constant is the failure of the iron piston skirt coating. This failure precedes the cylinder wear and often leads to it. Here you can see this delimitation of the coating clearly. Every piston in the engine has this, some worse than others. Even if the engine hadn't lost a rod bearing, it would have started to eat oil and would have picked up a "tick" that sounds like a lifter and it would have fooled a lot of people who may have done a lifter job on the engine, only to find that they had wasted the owner's money as the issue isn't lifters, its the cylinders failing.



And here is your classic 997S cylinder wear illustrated.



And its not just one cylinder.. Try all of them...




And.... this doesn't belong here. At some point one of the camshaft hall sensors died and lost it's magnet. No one bothered to fetch the magnet from the oil sump, they just left it in there. It bounced around and we found it laying between the IMS and the crank carrier. Classic.



The factory found this casting defect and prepped it for weld repair by die grinding it... But someone forgot to go back and weld it up. Thats what happens when Robots assemble engines. We'll have to finish the job for them..



Here's the close up of it..



And here's what we found as the culprit. This rod journal (#1) was losing it's rod bearing. The crank is toast, because its cracked from the damage, but the owner shut this engine down before it tossed the rod through the block. The bearing was still mostly intact, but heavily damaged. Had he kept driving the rod bolts would have broken and he'd be needing a new crankcase, and crankshaft carrier among with many other parts. We don't care about piston, cylinder or connecting rod damage, because the rods and pistons go to the scrap yard and the cylinders are machined away for Nickies anyway.




Here's a better looking rod bearing, you can see how the detonation was pounding the bearings and wearing through the dermis layers. This would have been evident if a proper used il analysis was done before this engine failed, and the results were reviewed by someone with a clue :-)



Yep. This one was certainly being "serviced as directed".... Never mind the chunks, those used to be rod bearings.



I interrogated the ECU in this car and its last over rev was 1,600 hours before the failure and it was only a range 1. The average MPH of miles/ operating hours is not consistent with a vehicle thats seen any track time. The average MPH is lower than most street cars that we see, so its probably spent most of its time on surface streets and hasn't hit the track.

What killed it? This one was going to lose cylinders very soon, it lost a rod bearing before the cylinder symptoms had time to make themselves evident.

The detonation damage is from one of a few things, or several things compounded:
-ECU tune that was done by some clown with a laptop that doesn't understand what raising ignition thresholds does to an engine internally

-Knock sensors going bad, not allowing timing to be pulled by the ECU

-Running lean. This one is not evident in the color of the combustion chambers or exhaust ports, though damage could have happened at an earlier time and is no longer evident.

My engines always see new knock sensors, but Robs will be fitted to an engine in my dyno lab and tested to see if they are desensitized. This may help us understand the failure dynamics better.

Once we get it back up and going we'll extract the file from the ECU and see if it has been tuned. I believe that we will find that it has and I would also bet I know which company did it once I see their tuning style. "Jacking up timing" makes power, but kills rod bearings, especially when someone doesn't change the oil and it lacks film strength. The last time I asked that tuner what the 4 strokes of a 4 stroke engine were, in order, he didn't know.

We will have to watch closely to ensure that some issue with this vehicle doesn't impact our new 4.0 engine reconstruction. Thats why I don't ship engines and we only install and test them here on site- because no one cares as much about our engine as we do, and the owner. Most shops don't care what killed the old engine, they just install the new one and if it "pops" they point the finger at us and make it our problem. Thats why I don't play that game, I only trust what occurs under this roof.

The owner of this car did everything right, and he saved himself thousands of dollars by shutting it down before it tossed that rod off the crank completely.


We'll be done with this one sometime in mid 2015.....

McQueen993

Wow. This is a great thread. Thanks, Jake. Aside from a used oil analysis what could have been done in a ppi to pick this up? I ask because I am looking for a 997.2.

Thanks again.

BED997

Really nice work Flat 6! Sad to hear the OP's story but he is in good hands.

I can't believe that casting defect photo, and how that would ever leave the assembly area... disappointing.

LexVan

Pull the oil filter. Inspect. Pull the oil pan. Inspect. Cross your fingers.

n1gels

Thank you for posting the engine tear down pictures and analysis, Jake. Although they're scary to look at, they are also educational for the rennlist community.

When all is said and done, this owner is going to have an engine we'll all be envious of.

Schpee007

Jake,

Fascinating to read your follow up on this motor. Love learning about how these motors work. My heart aches for the OP. Many kudos to him, and you, for sharing this event and making the learnings from it available to the rennlist community.

Would love to hear your wisdom, Jake, about driving these cars in cold climates. I live in CO and drove my car last winter when the roads were dry and clear (first winter I had the car). Car always fired right up, and never sounded strained, but reading this thread makes me question if that's good for the longevity of the motor (read I want my car's engine to last many years). Are there are minimum steps you recommend for safe cold weather operation? I have a DFI engine if that makes any difference in your take.

Definitely time to toss out Porsche's oil change guidelines.

One last curiosity question. Do the Mezger motors suffer similar ills, or are they the "bulletproof" benchmark for Porsche engines?

Cheers!

Bijan

Porsche now uses the DFI engine in their 911 range, including GT3 and Turbo S 560 HP.
The service interval is now a sensible annual, there is no reason to believe the 9A1 engine is not up to the Metzger standard. Admittedly we only have up to 5 years experience with it.

stronbl

Rob and Jake -
Thank you both for posting and keeping this thread going. I am appreciate the learning experience, but I empathize with Rob's plight - nevertheless it's a great attitude going forward as has been noted already.

Philster

997.2 = No IMS/B and cylinder wall coatings are superior to 997.1 engine

So, coincidence that IMS failure and cylinder scoring were issues on 997.1 and those two issues were addressed?

Here is what I have seen too often in cold weather with people who are driving like they have 4 quarts of oil and a common/generic engine, yet they own a high-performance, high-oil-capacity and high-cooling capacity car:

They run hard way too soon. They might never get the engine temps up, and the oil might remain well chilled for the entirety of their ride. This could go on for an entire season.

Sometimes, this is a by-product of life. Imagine a 997 owner with a 10-mile ride to work at 7 am on a bitter, cold morning... and the 997.1 as a daily driver... and they find they have to merge onto Le Crazy freeway before the engine is warm, and the oil is quite cold. They might not even know any better about the consequences of hard running a cold engine with ice cold oil... and it's compounded by the fact that the ice cold oil is already 10,000 miles deep into its service life. Say this happens over and over and over... for the 90 days of ice cold weather he gets in his area. Ugh.

I've ridden with a neighbor who was hammering his 997 before it warmed up. We had driven 5 miles in about 10 minutes, and his oil temp gauge was darn near pegged at the bottom. It was about 48 degrees outside. The engine was close to warm, but that is based off the fraudulent coolant temp gauge Porsche put in the 997's. It's an idiot light. It can't be trusted. Oil? COLD.

Take it down to sub-zero temps and it's hard to imagine how hard it might be on the engine to get into the revs before the engine is really ready for it. All over the frozen states of America, daily drivers are getting abused... because they are almost always running hard. Sometimes the engine is cold and tight with frigid, old oil. Repeat and repeat. Ugh. Sometimes the engine is warmed, but the oil is still old and cold.

Ironically, it's the things that are put in place to make our 997's high-performance cars that work against them in some situations. All that oil... all that ability to shed heat... the long time it takes to fully warm the engine and the oil... and the fact that Porsches have become more 'refined' means more people feel they are like any other car suited for daily driving -- except there's a chance they aren't... depending on conditions.

I always recall stories of people who care for old Italian V12's... whether they were old Lambo engines or old Ferrari engines. On one hand, they would care for them like delicate glass sculptures, ever sensitive of getting the oil warm... ever sensitive to how it starts, and how to properly shut it down. "Shes a-warming uppa." And they were the same ones winding them out like banshees. "You gonna foul-a the a-plugs if you don't-a run it hard!"

Nothing you do guarantees any result. You can only move the odds by your actions. People who pay no attention to winter procedures (oil and engine temps and oil life) might experience a 4.5% trouble or failure rate... and the guys who follow rock solid routines might experience a 1.5% trouble/failure rate.

Who knows... but I'd rather eliminate variables personally. Frequent oil changes, being sensitive to engine temps and really sensitive to oil temp as it slowly makes its way up... and take it from there.

.

Robocop305

Thanks for such a great write up. Please, let's keep this running.

Robocop305

You are right about these cold blooded beasts. I live in hot Miami and my car takes a good 10 to 15 minutes to warm up in 90 degree weather. I definetaly don't need a lower temp thermostat or a 3rd radiator. Sometimes, I wish my car would warm up sooner.

Flat6 Innovations

The UOA may not have shown this... Its the only thing that had a possibility of indicating a problem, outside of a sump inspection. A real PPI for these cars must include an invasive inspection. Guilty until proven innocent is the mind set that the inspector must have. This is what I instruct in my classes to a few hundred technicians per year.

This is a 997.1 engine. That said the Lokasil bores of the 997.1 were replaced with a complete Alusil block in the 997.2. Omitting the IMS wasn't smart, and using smaller timing chains and increasing their loads at the same has also proven not to be smart.

The 997.2 engine and their Alusil blocks also have scoring issues.
Here's an example that occurred at 4,165 miles in a 2012 model year engine. No track time, never even had a chance to have the first oil change.



And here's the bore wear from the same angle as Rob's photos were taken. Same engine, 2012 model year. Never even had time to get dirty yet... Thats ok, I turned it into my 4.2



We've positioned ourselves with the 9a1 engine (997.2 and up to 2014 MY) in the same manner that we did the M96/ M97. This was done by starting invasive procedures when the engines were only 6 months old. that meant buying new cars and taking the engines apart with 12 miles on them, and dealing with failures that people didn't want the dealers to fiddle with- they didn't want the same engine again. Building these engines for pro racing has also taught us a lot and gave us early opportunities to identify issues and test solutions in a demanding arena.

The 997.2 engines are today, exactly where the M96 engines were when the issues started to really show up- 5 years in. We are already standing by to address the issues that may pop up, and build these beasts into up to 4.4L beasts, with 4.2L being my standard build. See Panorama Magazine, December 2013 issue, pages 66-71 for a taste of Cayman X and my 4.2 engine.

My 9a1/ DFI engine classes begin in 2015 and the first two are already over filled.

I received this email just yesterday:
Oh yeah... To the guy that fired his engine up cold and gave it hell.. He needs to consider thermal shock that the components see when this occurs. This cylinder head was caught in mid failure from a similar situation that led to dislodged valve seats. We caught it in time and it didn't scatter.



This one wasn't that lucky.. Same failure as an aftermath.This valve seat dislodged and made the valve contact the piston, which shattered the valve stem and tossed it sideways into the seat. The seat split, went back up the intake tract and was sucked into a cylinder on the other side of the engine. There was nothing left to reconstruct on this one.

trcox57

Fascinating description of a situation by a true craftsman that cares about his work. Thanks for sharing Jake.