Quote:
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Originally Posted by Silverstreak
.... and under just normal driving conditions.....most with lower mileage. I read this on another Boxster forum.  Is the 3.2 motor at risk for the same thing? 
From what I understand the intermediate shaft fails and locks the engine up, and other cases a timing chain failure was mentioned. Since the 3.2 is just a bored and stroked 2.7, it makes me a bit uneasy since my car is out of warranty.
Between the RMS and this motor blowing up thing (if it is true) I find it hard to believe Porsche builts such poorly designed engines. The post 77 911 Carrera motors seem to be ultra reliable, what gives with this Boxster design ?  |
Hi,
Say it ain't so Joe... Unfortunately it is.
The 2.7L (
M96/22,
M96/23), and the 3.2L (
M96/21,
M96/24) suffers from a redesign where Porsche added a larger bearing on the Intermediate Shaft (
#6 in the Pic below, Flange Bearing on the sprocket end) to supposedly reduce vibration.
As a result, failure of this shaft has become much more prevelant than in the 2.5L - (
M96/20). It also affects the
M96/77 engine on the 996 to essentially the same degree, and they're starting to see it on the 987/997s as well, so don't feel like you're alone.
What happens is that the bolt which fixes the shaft on the rear (Flywheel side) of the engine breaks allowing the shaft to
whip around internally and take out everything in it's path.
This failure takes the
#2 spot behind RMS failure. There is nothing you can do to prevent, or forestall, these failures.
But, realize that you are one of the Priviledged Few (yea, right) to own one of these magnificent cars, so what if you have to occasionally flip $1k-$12k for a new motor to keep it running by putting the same design-flawed engine back in it? Stop your whining!
There is
NO reason to forgive mediocrety in engine design when a variety of makes (including many American made cars) are able to produce high powered, sophisticated, engines that easily survive 200K miles without leaks or breakdowns.
There are bound to be defenders of the Marque (most of whom have not yet succumbed to these failings I suspect), who'll dispute this in one form, or another. But, Porsche engine reliability is a
Myth, pure and simple. They have had Casting and Web failures and flaws going all the way back to the 356 engine, eventually, they will ALL fail, though some of the AC engines will go 200k mi. before doing so.
And because the all-new
M96 engines are
So Great and so much better than all the old
rubbish, Porsche still has to use the old crankcases for their Turbo and GT3 engines. But, you have to shell out the really
BIG bucks if you want to play with those...
Happy Motoring!... Jim'99
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