Best/least bad version of M96/97
 

I had hoped that my '03 S M96.24 engine was one of the better M96 engines that Porsche made. Looking into it further it seems that there are still significant issues other than just the IMS bearing issues. I was honestly kind of dismayed to discover that. Now I wonder if there is such a thing as a "good" M96/97. I will say that in my business I generally see just the "problem children", and I will freely admit that I have a rather pessimistic attitude as a result. I have now seen six totally destroyed M96/97s (including one built by Jake's shop, although I do think the issue was tuning and/or user error rather than the mechanicals), plus a few with "just" IMS bearing failures.

I also looked into the design of the newer MA1 engine from '09+. This is not simply an evolution, but rather a clean slate, start over, clear the desk design. I note that even the engine code seems to denote that they started from scratch with that engine, and from the construction it is apparent that they did. The cam and oil pump chains are now driven directly off the crank. No more IMS, no more sealed ball bearings in the engine (duh...). There is no more separate crank bearing case, the crank is now held more conventionally directly between the case halves. The case now has a stronger closed deck design rather than the unsupported, cast-in sleeves. The heads no longer have a separate cam follower housing, but rather the hydraulic cam followers are housed directly in the head, in what I would consider to be a more conventional manner. Honestly, the engine looks more in common with a Subaru than the M96/97. I don't consider that to be a bad thing.

Anyway, originally I had thought that my rather low mileage '03 S would be something that I would build into something for autocross and DE events and keep a long time. Now I am starting to think that putting a lot of time and money into it is not a great idea, and perhaps it should just be something that I enjoy as is for a while as is and than look for an '09+ as a better "investment". Thoughts?

A pessimistic attitude and the frequency of the problem children is typical of what you will read about the motor on the internet. Rarely do you read about the high mileage motors where owners have had, except for maintenance and replacement of worn out parts, trouble free and fun driving.
Granted the motors between 2000-2005, which were the motors in the class action lawsuit, have the highest percentage of failures due, primarily, to the switch from a double row to single row IMS. Consider the total number of cars built in those years and those percentages are not that many actual cars that went belly up.
Still no one should own something that causes them constant worry, life is too short for the constant thought that something will go wrong because it will put a worry factor into everything you do with it.
Sell it and buy something you won't worry about (so much) and can have fun with. :cheers:

Plenty of owners on this forum with high mileage Boxsters.

m97.2 (2009-2012) is the best of the bunch with DFI, no IMS, and 4 scavenge pumps in the heads. A much more stout engine from a design perspective. The 981 is better still. That said my lil 98 2.5L Boxster with 115k miles, 100+ track days is a great result for any platform. I think it is far better than I did with earlier Chevy, Ford, and Nissan motors that were taken to the limit often.

No engine platform is perfect and all of them have warts (even Miata). If it survives the factory warranty, it meets the minimum design requirements. If it lasts 3x the factory warranty, it is pretty darn reliable by modern standards. You can now buy 3 early 986 cars for the price of one good used 987.2 car. That is paying an extra $20k up front for risk avoidance if you buy the 987.2 car. $20k will buy a lot of tires, repairs and maintenance.

Choose wisely.

Qumulus,
The big problem I have is that the issue you raise seems unpredictable. It isn't miles/abuse/year related. The good/bad outcomes are randomly scattered.Hence the disparate views from single owners.
Another unpredictable issue is - how much initial and collateral damage will occur? Minor issues like a water pump impeller disintegrating can cause lots of subsequent damage beyond the minor cost of a new pump.
Further ,there is seldom much warning of impending doom.

These three factors lead me to a seemingly bizarre but logical(?) conclusion beyond the standard 'get a PPI" . Buy a competently repaired Salvage Title car. Keep the $5000-10000 savings as a reserve for preventative maintenance/repairs. I usually keep cars a long time so the trading issue is irrelevant to me. And I know how to inspect for body/frame damage.
I agree with your 2009+ target. If you get PDK, consider finding the 'Sport Chrono' to avoid the anemic acceleration problem of the non SC cars ?
It will be interesting to read about what you eventually do. Selling an '03 that is running fine may seem silly - until it becomes and instant roller worth $3-4K.
Good Luck!

I really don't know the answer to this issue. I love 'Porsche'. But there seems to be a lot of risk! I don't want an old car so air-cooled are out ( nor a garage queen). I too am thinking 987.2, or a 996 TT. My M96 is behind me :chicken: even though it was by far the most rewarding car I've owned I'm feeling optimistic about my future engine ownership. :dance:

Porsche - not even in the top 10.....

10 of the worst engines in history | Autonet.ca

As some have said - the overall fail rate is really very low compared to many other vehicles out there. And when you correct the IMS - the fail rate is tiny.

Interesting list. While growing up my family had three of the engines listed. We had a wonderful new '79 Olds Cutlass Diesel 5 speed manual (one of 150!) that went through head gaskets every 40k or tank of bad fuel, which ever came first. It also ate a couple of injection pumps and had an electrical fire that almost totalled it. While still under warranty the service manager at the dealership Dad bought it from asked Dad not to bring it back anymore, as it was clogging up their service department. Nice! My brother had an '84 Pontiac Fiero with the Iron Duke 4 cylinder. Gutless, but it was actually very reliable. Mom had an '85 Chrysler LeBaron GTS 2.2l that finally blew a head gasket at 175k, but had no other real issues.

Of all of the engines listed there, I can't think of any of them that had a class action lawsuit to replace engines for up to ten years after they were produced. Hmmm. There should have been one for that Olds Diesel, but no one would have wanted to drive those POS's for ten years anyway...

[QUOTE=Qmulus

Of all of the engines listed there, I can't think of any of them that had a class action lawsuit to replace engines for up to ten years after they were produced. Hmmm. There should have been one for that Olds Diesel, but no one would have wanted to drive those POS's for ten years anyway...[/QUOTE]

You have to remember that back then, the only way you knew of potential issues was through word of mouth, mechanics etc. we didn't have today's Internet forums to share similarities/issues etc.
I bought two lemons not having learned my lesson the first time, I had a Triumph TR7 that I could barely drive outside city limits, then I bought a Lotus Esprit that I could barely keep running at all, so imagine my excitement when I bought a 14 year old Porsche that I use a DD in the summer an average of 1.5 hrs each way to work and turns heads everywhere I go!

Quite right... I too have had a bunch of English and Italian cars, including Triumph TR3, TR6, GT6+, Spitfire (2 of them, still have one) and a couple of Alfas. All of them had something you could consider an Achilles heal. Like thrust washers on Spitfire cranks, TR6s cracking rear suspensions. RUST. The nice thing about the Triumphs was that you would have a hard time ever spending more than a couple hundred bucks on parts to fix them. They needed LOTS of parts and quite often...

That background does make me appreciate the Boxster quite a bit. It is a thoroughly modern car that does everything better than the old stuff ever did, even if it does lack some of the character of the old roadsters. The only one that I sort of miss is the Alfa Romeo Spider. There is something special about driving an Alfa.

Interesting that 5 of the 10 worst are from GM

Comparing old cars to newer is pointless. There is no doubt newer is more reliable. Also Porsche produced few cars (even Boxsters) and as a result won't even register in some 'studies'. For me the problem isn't really the IMSB as I had LN"s installed soon after purchasing the car and never worried again. But the engine is incredibly time consuming to work on and it's so easy to screw something up when inside it. And there are so many potential 'fails' that can cost more than the value of the car to correct (since it's this far apart it might as well be rebuilt...) As an example if a crank bearing 'goes' ( common on M96) you're looking at a massive total rebuild whereas in most other engines you drop the oil pan and replace and go...

Woodsman,
I agree with all you said.
So which Boxster(?) will you buy next ?

09 S or newer unless I go with a 996 TT. I may also purchase an 2000-4 S to strip down and make a street/track toy. I felt my previous Boxster was too nice to do this to.

Interesting. We are on the same page. I also think the 996TT is the next logical step. A friend of mine just picked one up. Incredible car for the price. They are quite high in bang for the buck sharing the body and interior with the M96 powered 996, but having that wonderful and pretty much bullet-proof Mezger engine. Pricewise they are comparable to '09+ Boxsters, but have a lot more performance. My problem is that I like roadsters and the 996TT Cab just doesn't do it for me.

Sooo, maybe keep the old Boxster AND keep options open for a nice black/black 996TT.

The 2.7 by far is THE best engine. This goes for the 5 chain and 3 chain variants.

Last year I only saw 2 of those engines fail, and one had 190K miles on it when it popped.

Curious - what was it that caused the 2 to fail?

Yes, the cars with the Mezger engines. They seem to fail much less - around 0.5 to 1%. Which is a very normal number if you campare it to other sports car manufacturers.

The DFI engines are new from scratch, that's right, But they also have problems.

I would go with a water cooled Mezger.

PS: Never forget, that the production in the Wiedeking era was driven by as low as possible production costs and by a maximum in production efficiency.

One tossed a rod bolt, the other lost an IMSB

Does a 2.7L replace a 2.5L without a lot of adjustments or ECU issues?

There is a good article in the March issue of GTPorsche about the M96 engine.

Here's the engine swap Tech Article on PelicanParts:
Pelican Technical Article: Boxster Engine Conversion Project - 986 Boxster (1997-04) - 987 Boxster (2005-08)

The 2.7 will need to be adapted for the throttle cable and the car will need a DME/ECU upgrade.

Thanks, a lot of good info there.:cheers: I was just looking at used Boxster prices and they have dropped so low that, if your 2.5L does die, it would be about the same cost to buy a used low mileage 2001 S as to do a motor swap with a new motor.

How do you tell a five chain from a three chain? What would entail installing one on a '99 Boxster Tip in place of the 2.5L Tiptronic? Would it be the least expensive bang for buck replacement if the 2.5L goes? Thanks.

Dang, I thought I was all set in looking for an 'S'.... but now I read this..............:cool: