Rod Handsfield

The folks on the 996 list are VERY sensitive when queried re engine failures. In researching this topic I have encountered enough reliable data that the 996 as well as the Boxstes engines are considered to be DISPOSABLE. Many stories of catastrophic failures at low miles and also failures in Porsche factory replacements. I've owned aircooled Porsches and several 928's' - those engines have been bulletproof. What is the consensus regarding the robustness and longevity of the 997 engines? Thanks for not telling me to use the search feature.

Soulteacher

Yes, the search function is a veeery dangerous thing... once you start using it, you cannot stop... sooooooo much information... we don't want that... I wonder why they even invented it...

Oh, and to answer your question: based on previous threads, the consensus is that they are robust and reliable.

ECS

One data point only. 06 997S DD and have run about 10 DEs with only minor mods (e.g.brake lines, more brake cooling), 12k miles and the cars perfect. No RMS issues.

Ray S

Rod,

All 997's (except the TT, GT3, and the new Mk II's) use the same basic engine as the 986, 996, and 987's. The motors have been improved over time but they all have the same inherent strengths and weaknesses.

Edgy01

You can't base your engine reliability upon the postings of a few (relative to the numbers out there) owners.

As a long time Porsche owner/driver I would say that the latest offerings from Porsche are pretty tough engines. There have always been issues with Porsche engines because they're expected to go above and beyond that of ordinary cars. Many owners also abuse their Porsches and expect them to take it.

Don't believe for a moment that the older Porsches didn't have issues. There were issues with the chain tensioners for literally decades,--from 1964 through to 1984. Also, rubber hubbed clutches,--lots of issues.

Bob Rouleau

Most of the failures were on earlier engines - the original 996 3.4 for example. Nothing much seen aboout the 997 - improvements have been made. Obvioously not perfect otherwise PAG would not have invested in a brand new engine (9A1) in the latest 997s. No balance shafts, no intermediate shaft and they claim RMS issue resolved once and for all in the new design.

p-cardriver

Not a representative or statistically valid sample, as someone already mentioned. But FWIW, I have over 23k miles on my '07 including 9 DE days in about 367 days, and have had zero issues with the engine, clutch or transmission. Also very little oil consumption in my car.

Speed

I had two 996's, a 1999 and a 2002, that each had 50000+ mi. when I traded them in with no engine problems although the 1999 had the RMS replaced at 15k mi. My 2005 997 just passed 50k mi. and, again, no problems of any kind.

rnlarctic997

I really think these engines need to be exercised regularly...my '05 997 C2 now has 70,000 with [I]zero[I] issues. It's my daily driver and includes several autocrosses, and DE's in her life. I think failures are due to infrequent use combined with abuse as Dan had mentioned. No RMS leaks and about 1 qt. of oil for every 5,000 miles or so ( I change oil/filter about 7,000-7,500miles). I view the new 9A1 engines as being potentially better still with less parts, stiffer case, and new oiling system.

cviles

I've noticed a spike in reports of engine failures lately on some of the boards I read -- mostly due to IMS failures. Having just had the engine in my '05 987S replaced at ~25,000 miles due to IMS failure, these threads get more of my attention. Some of these are older cars, some are newer models like my Boxster.

But as Dan says, you can't base your judgment on the failures reported on the Web. The sample size is too small, it doesn't represent the full spectrum of owner experiences in the "real world", and has the built-in bias that people who aren't having problems don't usually report that "hey! I have no problem!" Only Porsche knows for sure how often these engines die and for what reason.

Just remember that every mechanical devices has it's own failure modes. This includes the M96 engine family as well as the old air-cooled engines. Even the new DFI motors will have weak points, we just don't know what those are going to be yet.

tmc

One difference from the M96 to M97 is the intermediate shaft: it was strengthened in the latest version of the engine. In addition, the RMS seal's latest design "seems to work" and many less RMS issues are being reported.

You can read the article in Excellence for a list of syndromes. Note though that the authors are discussing failures that they have catalogued, not the occurrence of these failures. Any engine has failure syndromes. One should not take the Excellence article as a statement that the M96/97 is fundamentally flawed. Rather, the purpose of the article seems to be that there is a growing aftermarket of repair options for these engines and there will be significant support for the engines as they age. In other words, the article aims to state just the opposite conclusion of what some people are drawing from it: with a growing aftermarket repair infrastructure emerging, a car with this engine can be maintained for a very long time.

tmc

BobbyB

I put over 50K, on my Boxster w/2 RMS, but no IMS. My 993 had a RMS issue - these things happen. More are reporting the issue but as others have said, very few owners are reporting in that they haven't had a problem. Enjoy every minute you can behind the wheel, the chances of a total engine failure is very small.

machina

I believe the MY 2006 cars had the IMS and RMS update but is there any way to tell for sure by engine number? Somewhere I found these numbers relating to RMS update but was never sure if that included the IMS update as well.

M96/05 695 09405 (3.6L)
M97/01 685 13598 (3.8L)

Macster

Just kidding, sort of. Been too many posts of engine failues to believe these engines are bullet proof.

Can't really comment on the frequency or odds of an engine failure and there doesn't seem to be an common thread to these failures.

Best advice I can offer is to drive the car. The more the better. Worse thing is to buy new car with its 4 year 50,000 mile warranty and then rack up very few miles and warranty expires on time and not for miles. Almost all problems are from miles not time so the thing to do -- or consider -- is while engine under warranty to drive the car. Ideally I think one wants the warranty to expire from miles at about the same time it would expire from time.

I have since the car new followed 5000 mile oil/filter service schedule and have used mostly Mobil 1 0w-40 oil. There's some disagreement whether this is the best oil nowadays due to its losing some of its anti-wear additives. (Quite a few oils have had this anti-wear additive package reduced. The worry is the additives can over time foul the emissions hardware: O2 sensors, converters. Maybe. But my car's on its original converters though the #2 converter is wearing out (P0430 DTC) but I'll take a worn out converter any day over a worn out engine...)

For cars that are driven regularly and receive regular and relatively frequent oil services not a big deal. perhaps. But for cars that sit long periods of time unused maybe a big(ger) deal.

Sincerely,

Macster.

Kurt_OH

Check out this video of 997 engine testing during development:

http://www.youtube.com/watch?v=fv53RbvgfGc