Andrewck

My car now has 115k miles on the clock and by all means appears to run strong, but the thought crossed my mind the other day: what eventually kills these cars?

What's going to be the downfall of my M96 and with regular preventative maintenance, what's the reason they can't go 500k miles?

(I'd like to leave IMS out of this as there are a couple of different schools that won't be solved via this thread).

cinellipro

Plastics in the internals that will just not hold up.

Kalashnikov

They just fail. Regular maintenance or not, plenty of M96 motors died with no prior warnings or signs of trouble. Chain tensioner failed, rod bolt backed out, something got jammed into timing chain, oil pick-up screen got blocked, you started the car when it was cold and scored the cylinders, IMS bearing whatever.

M96 is no honda motor. There are freak cases of M96 motors lasting for very long miles (cue Macster), but there are a lot more stories of motors dying young and without any prior symptoms.

kromdom

M.O.F. leading to C.E.F. ..... lots of them in a book somewhere (yup, doing a Krazy K homage here)

Gonzo911

Sigh....

jb1007

Like any car, drive until it dies. Enjoy it.

Schnell Gelb

There are 28 Modes of Failure for the M96 at last count.
The best advice offered seems to be 3K miles oil changes with the best oil,full flow filter and regular checks of the w/p and magnetic sump plug.
Check in here for engines noise diagnosis as soon as they start.
That will probably eliminate more than 1/2 the issues.
Others may help you by adding more suggestions if e can avoid this becoming an oil thread.

TonyTwoBags

There are some youtube vids out there on the different failure modes with examples, but I try not to watch them for personal reasons.

Gonzo911

The over/under is 7 pages with pages 5-7 having absolutely nothing to do with the OP's original question...

Kalashnikov

Here is a rare M96 MOF that KrazyK (UNFAIR) has experienced, in his own words:

My car was idling like crap the other day so I figured since I just got it, it may have been awhile since anyone changed the oil out. I decided to go ahead and change the oil. I used DT40 synthetic oil like I was recommended on here. Anyways, I drain out the oil and noticed it was extremely dark and even after 10 minutes of draining, it was still coming out. I decided to go ahead and flush it to make sure all the bad stuff got out. I hooked up the hose, ran water through the engine, started it up and was waiting for the water to come out clean (The engine never went above idle so I was told this would be ok). Anyways, About 3 minutes into this, then engine starts shaking and shuts off. I figured it was all cleaned out so I plugged it up, added the oil and figured I was ready to go. WRONG! The car won't freaking start now. This car has been nothing but trouble for me, I think I am done with it.

Turbojamie

I think this website contributes to many failures each year

Macster

There is no reason other than the engine is only as good as its weakest part.

Generally a major engine failure takes a car off the road at least off the road as far as the current owner is concerned. Obviously this can be a failed rod bolt, or a failed rod.

But a not to be overlooked contributor to an early demise of an older car is an accident. With a high miles older car a few thousand dollars in damages can be the final nail in the coffin.

It doesn't have to be a major internal engine failure either. An owner just gets lazy and lets a cooling system leak go. The engine suffers some localized overheating and in the case of the 996 a head cracks. The owner is faced with a pretty big expense to address this and decides to off load the car.

Or the owner ignores or tries to nurse a noisy water pump and the water pump sheds its impeller plastic into the engine. The owner is looking at a major expense and with some risk he is putting money down the drain as maybe the engine's cooling system is compromised and the engine will overheat even after a new water pump, et al, is installed.

Or the cabin gets full of water due to overflowing body water drains. Or a leaking door seal. (I've already had to replace both of these in my high miles Boxster.) The owner is looking at big bucks to address this water damage and that's the of the car.

Less common but still a possibility is the car gets put aside for a short while which turns into months. Now the car needs work to get back on the road. And maybe it has had mice at it, too. Kiss the car goodbye.

Or the owner ignores some noise that proves to be say a failed chain tensioner. While the chain remains intact the tensioner fills the engine with what looks like (and are in some ways) scary bits. His tech gives him the bad news which is probably engine R&R with a tear down and "rebuild". Big $$$$ are tossed about and that's the end of the car.

It takes some work to get big miles out of a car. One has to adapt early on (the earlier the better) a reasonable servicing schedule and follow it. One has to keep an eye/ear/nose tuned to the car for signs of leaks, or noises, or smells (caught my Turbo with a leaking water pump when I caught a whiff of anti-freeze and had the car right over to the dealer and the tech spotted the water pump leak sign).

Not be overlooked is taking care of the little things. It helps, some, when a big repair comes up to at least know the rest of the car is sound. All the systems work and work right.

Also, besides work it takes some good luck. My Boxster has been hit in the rear twice. Both times stopped at a stop light, too. First time caused over $5K damage: Just a front and rear bumper cover, a head light, and a tail light assembly and not including the $1500 I received for loss of the use of my car for 30 days.

Wouldn't have taken much more damage I think before the other driver's insurance company would have just called the car a total loss and written me a check.

My Boxster has over 305K miles on it. I'm going to continue to drive it as long as I can afford to keep it on the road. And compared to what a replacement car costs -- and I'm not talking about a new Boxster or even a nice used example -- I can afford to keep the Boxster on the road a long long time.

TonyTwoBags

You mean stuff like your posts?


*will self destruct in a few mins for cleanliness.

targa996

There are multiple failure modes that have been discussed ad Naseum in these forums. Read the flat six web site for example for details. A better question might be - what can I do to minimize chance of catastrophic failure ? Even that should be obvious

1. Frequent oil change - and we could go on for ever about the oil debate

2. Don't rev about 4K until oil is up to temp

3. Avoid excursions to rev limiter and beyond

4. Track time on unmodified car

5. Preventative maintenance on water pump and other items that could cause engine to overheat etc.

Gonzo911

Just wait and see...