Bruce In Philly

CaymanPower is a bit quick on the draw concluding that smoke = engine destruction (or ticking is a bad valve).

We who have been around flat six engines know it is part of the charm having oil pooling in the heads. Upright inline or V configurations use gravity to remove oil from the heads while Porsche's flat, boxer configurations use scavenge pumps to remove the oil and some remains on occasion hence smoke.

I am the paranoid type having two Porsche engines blow, but feel pretty good, so far, that the DFI engine is a good one regarding reliability. Do some blow up? Probably..... but it is below the statistical noise and no worry for me.

Peace
Bruce in Philly

By the way, another example of smoke on startup are those big radial aircraft engines you see in the movies especially from WWII. When they fire up, you see tons of smoke. In a radial engine, some cylinders point downward and always have a bit of oil in them that gets drawn in and poooof.

Click here for smoky radial engine startups.

ADias

I suspect you know that but... my comments above are not aimed at you. Your posts are factual and on-point. Unfortunately others take yours and others' posts to posit a bunch of nonsense and misinformation.

Bruce In Philly

I take no offense at all. I find it fascinating how we humans internalize everything. "I don't like silver cars"..... "Hey, what's the matter with silver! My car is silver! You're a jerk!" This phenomenon is something I find really interesting and I see it all the time on forums. I will say it is better than when this whole forum / bulletin board thing started many years ago... way more flame wars and insults.

An interesting example is when Jake Raby posts pictures of engine carnage. I LOVE his posts. I don't really know why I do, .... I guess its like rubber necking an accident or I like peeking at the engine internals... something we don't normally see. Others take offense... why? I don't know but I suspect no one wants to even think that maybe.... just maybe.... their baby is ugly.... even though the general stats are way in their favor. I can understand this, but then personalizing and attacking.... very very odd.

Cripes, it is just a car. Turn to another channel.

Peace,
Bruce in Philly

ADias

The issue is that the absolute statements made about chronic failures based on very limited samples is a bad thing. The 'specialist' repair shops think they know better and Weissach knows nothing, and PAG's aim is up to fool us all, but that is wrong. The field failures are small, even though the repair shops dedicated to these various issues, see most of the problems, there lies their statistical pronouncements' fallacy. It's like going to an ER and concluding that everyone in the world is sick.

The fear mongering has devastated 996 prices and that is simply wrong - a ton of great cars selling at econobox prices because people are afraid their 45,000 mile car will die tomorrow instead of its more likely 200,000 mile lifespan. The M96/M97 engine is quite solid. Does it fail? Sure, but these are not Corolla run-of-the-mill 4 bangers and they have a performance/reliability tradeoff. How they are used or abused matters too.

The 991 powerplant has been shown to be very solid. But we already see all the fear mongering regarding valve conking (a non-issue) and the specter of cylinder scoring. Cylinder scoring has been blown out of proportion on every flat 6 generation and short of a few lemons, or abused cases, a non-issue.

I, for one, refuse the forum paranoia and conflicted pronouncements. We as P-car fans should enjoy our cars, understand what they are all about, be adults about their issues and refuse the negativism trap.

Wayne Smith

+ 1 all the way! Glad to have and proud to have what has proven to be a damned bullet proof car (2010 C4S with PDK). Kudos to the Porsche engineers as far as I am concerned.

CaymanPower

I didn't say that. What I did say and I keep is this:


It's fascinating how people keep using the very same arguments over and over again but only now, with the 9A1 engine, they are willing to reckon that Porsche has allegedly and finally corrected all the well KNOWN design flaws of the past WC engine designs, despite the fact they keep using the very same arguments they've used with the old designs for years. This goes a long way towards those arguments credibility.

So, it's not a surprise that you find surprising that your engine doesn't smoke upon startup.

CaymanPower

Here's a fact for you... no matter what I did to my 9A1 engined Cayman (and I owned two - 2009/2010) the engine ALWAYS smoked, albeit occasionally, from one side ONLY: rear left side - cylinder bank 2 (with a 911 the rear left side means cyl. bank 1). This is all very well documented elsewhere in this forum.

So, how come Porsche is able to build three horizontally disposed engine cylinders that never smoke but not the other three within the same engine?!

Wayne Smith

Hartech in the UK put together a fantastic report on the Porsche flat 6 motors. You can Google this and download the pdf. It is long, but worth reading.

Within that report they point out why one bank is much more prone to damage and smoking than the other.

On the 9A1 motor the oiling methods and pressure controls were significantly modified. I believe this addresses those Hartech concerns.

There has been mention of the DFI spraying the cylinder walls. Bruce in Philly addressed this with Porsche information showing the DFI is directed into the intake valve rather than down and onto the cylinder wall. You will find a wonderful diagram from Bruce that was so good that I copied it into the Information Section of my Vehicle History Manual.

The DFI direction also deals with carbon buildup that has been a concern on other cars. This may not be a full solution (earlier pathways from the AOS to the valve) but I have not heard a lot about problems regarding carbon build up. And the motor has been around long enough now to have a statistical sampling.

In my mind the only thing left is vaporization. The fuel has a very short path to mix with the air to create a uniform charge. But if you look at the performance of these cars, I believe the engineers at Porsche have been successful here as well.

Can the 9A1 motor fail? We'd be idiots to believe otherwise. But until we have examples that are worth studying so that we can modify our maintenance habits to better insure our reliability, I've got a lot more valuable things to worry about. Just saying.

Bruce In Philly

Everything you noted is spot on, IMO.

I would like to temper this just a bit given two experiences I/we had. The first is that the shop foreman of my local dealer, who now has is own indy shop, had worked for a Porsche dealership for... i dunno 25 years or so.... made an interesting comment to me in the early 2000s when these engines were blowing at quite a clip. I asked him something like "what does Porsche say about these failures?" He came back with a non-flattering comment. Something about "denial, arrogance, and tight lipped". He meant his comment to be general about Porsche and not specifically to the failures at the time. A different mechanic who replaced my first engine failure at an Atlanta dealership (thank goodness it didn't blow between Philly and there) made a similar comment that "Porsche will never say a word" and "they tell us nothing".

Now my above comments about being tight lipped are not necessarily a bad thing and even reasonable, but given our second experience: Porsche lost a class action suite on IMS failures, and you can see a culture that is not exactly ..... um... customer focused. Obviously they are protecting their brand. But, BMW had engine problems with their M3s at the same time but they handled it differently.. .they sent letters to their customers noting the issue and extended their engine warranties to 100K miles. Porsche just denied it.

Of course hind site is 20/20 and "How To... " handle these type of negative experiences are written about in management science texts, but Porsche, IMO made a tactical error in denying a problem. They should have taken the BMW route and backed their product. Instead they were dragged through the wacky court of both public opinions (these forums) and the American legal system and lost a major law suite. Not good management decisioning IMO.

BTW: When Nasser dragged ford publicly through the Firestone tire issue, he was fired (there were more reasons of course, but this kind of publicity shows poor management skill of the worst kind). I believe there would have been no class action suite if Porsche too the BMW route, and we all would have praised Porsche for their actions instead of the negative press we see on these forums.

The only other nit I have with your comments, and I do agree with everything you posted, is about the role the law suite loss plays in the lower used pricing vs the impact of the forums alone. I think the law suite loss is the "science" behind the price drop and the most significant factor in the price drop and not just the wild speculation and fear mongering on these forums. It is hard to argue with a lost lawsuit.

Peace
Bruce in Philly

Here is BMW's letter to customers issue IIRC circa end of 2002:

Extended Warranty on all S54 Engines in M3 coupe, convertible and M roadster and coupe model year 2001, 2002, and until further notice, current production 2003 (Vehicle Identification Number specific).

Dear Valued M Enthusiast,

We hope that you are continuing to enjoy your M car and that your BMW ownership experience is everything you hoped it would be. At BMW of North America we are committed to maintaining a level of automotive and service excellence that exceeds your expectations now and in the future. We are grateful to you for your passion and enthusiasm for M cars.

BMW has always maintained an open dialogue with our valued customers and BMW centers. As you may be aware, we have seen cases of damage to the connecting rod bearings resulting in engine failure. We are listening to your comments and concerns and have been meticulously researching this issue. We promise to keep you informed of any issues that affect your vehicle’s engine.

To further strengthen your confidence in your BMW and assure you of our commitment, we will extend the warranty on the above referenced vehicle identification number for all internal mechanical engine components that are lubricated by engine oil to 6 years or 100,000 miles whichever comes first. Enclosed is a copy of the extended warranty statement for your records. Please insert this page into your Service and Warranty booklet, as it is transferable to any subsequent owner.

We continue to recommend that you only use BMW approved SAE10W-60 synthetic oil in your engine. Please be aware that your engine needs to be at operating temperature before you take advantage of its full power at high engine speeds. Please do not overrev the engine under any circumstances. Be careful not to pump the accelerator pedal when there is no engine load, e.g. when the vehicle is not in motion. The best, most efficient and safest way to warm up an engine is to drive with moderate engine speeds until you reach the operating temperature.

We assure you that we stand behind our product and will always continue to listen to our customers. If you have any additional questions please contact your authorized BMW center or call Customer Relations at 1-800-831-1117.

We wish you many more safe and thrilling miles in your M car.

Sincerely,

Hans G. Duenzl
Vice President,
Aftersales & Engineering

workhurts

I'd like to add, that wrt to BMW, they changed out the rod bearings on only M3 and failed to provide a recall for the M Coupe and M Roadster. They did provide the extended warranty on both. I just came on here to read about carbon buildup because a colleage is looking at an S5 and was concerned about the DFI engine given his prior experience with a Q5 and carbon buildup.

Anyway, I still try to get my engine nice and hot every once in a while to clear out whatever carbon buildup there might be. Even though, from reading this thread, there appears to be a minimal problem with buildup is there anything preventative that can be done to minimize the issue even further?

CaymanPower

Yes! Audi adopted both direct and port fuel injection simultaneously for their late engines, a la Toyota D-4S fuel injection system.

7391420

I think the rule that applies is always that new technology takes time to be reliable.

Port injection is tried and true, DFI is new. It's definitly better, cleaner, more efficient but it applies technology and components that won't have the track record of decades of use until decades have passed.

I wonder if any of the late model cars will be as reliable as the legendary 3.0 and 3.2 air cooled motors?

david

I too actively wonder about this, especially after driving a 3.0 >200k nearly trouble-free miles...as you mention, time will tell...

user 72902

That's an interesting point. Here is an example that I know the 993's had two distributors each providing a spark plug to each cylinder (two sets of wires and 12 spark plus). I don't know how efficient that system was but the redundancy was good for endurance racing; if one system failed you still had ignition supplied to a cylinder. So you were down on power but still running.

CaymanPower

Nothing new about DFI. It's not so much a question of technology but a question of taking advantage of gasoline's strong solvent properties, like in port injection, and try to avoid their negative effect of oil depletion from the cylinder walls when direct injection is used.

Audi, like Toyota before them, acknowledged that carbon build up on the intake valves and stems would always be an issue without port injection, so they've adopted it in a complementary fashion to direct injection.

On the other hand, bore scoring seems not to be an issue to them as it is historically to Porsche's water cooled boxer engines, with or without fuel direct injection.

So, is that a weakness of all rear and middle mounted boxer's 6 cylinder engine designs doing above 7000 rpm for daily commute duties?!