another dead boxster @#$%!

[seningen]

Originally Posted by Jake Raby

JTP,
Thanks for the kind words...
I wanted to take this opportunity to illustrate how these engines should be cared for and examined when they have had potential failures..

The general way a shop attacks a problem like this is by "throwing parts at it" to see what repairs the issue.. This engine also had all the classic examples of a total failure, so many would say "its blown up, replace it" when the reality of it is the engine might not have had much going on at all..

Its too early to say, but I am hopeful that we can have this car repaired within 48 hours from the time it failed... It arrived on the perfect day, we are awaiting parts for every other job in the shop!!

Mike,
If this rod is bent, it has not been shortened, it has more than likely been twisted in the bore, which is how I have seen these rods deform in the past with hydro-lock.

You've got way more datapoint -- the one I saw curled over with a bow -- I'll have
to dig it out and see it actually twisted and see if I can determine
if the stroke would have been shorter or not.
Always trying to gleam some information from every failure to
make the next go round easier.

As others have said -- thanks for sharing!

Mike

[Jake Raby]

Learning from failures provides exceptional experience.. Thats what we do and have done, even with our own test engines.

Now, the results are in... It appears that Pat dodged a big bullet!!
We detached the AOS charge hose to the intake and blocked it off, filled the engine with oil and fired it up..

It smoked like a freight train for 5 minutes and then started clearing up!! There were ZERO mechanical sounds from the engine from start up to full warm up so I feel the issue is the AOS.. I also feel the engine is mechanically sound.

Now we will install a new AOS .. I'll then drive it home tonight and put some miles on it under a watchful eye, then tomorrow we'll repeat the compression and leak down tests and compare numbers to ensure the episode didn't hurt anything else.


NOW:
What people need to learn from this is simple.. IF Pat had cranked this car back up after this extreme episode he would have been in trouble.. The #1 cylinder was half filled with oil, just a bump of the starter would have hydro-locked the engine and created a cylinder/piston/connecting rod failure in short order.. Thats because engine oil can't be compressed to figures as high as the CR of the engine, near 11:1.. Something has to give and something will break.

I think this one was just an extreme AOS failure, we know that everything else is fine..

BUT Pat has an IMS bearing thats at a very early stage 1 failure and he has to make up his mind about what to do. With the car at my facility, the wisest decision is to retrofit that puppy and be done with it.. With seal material in the sump, I feel OK test driving it and doing the rest of my work, but I'd do something very soon...

I won't be dynoing this car until the IMS bearing is addressed, the liability is too high to stress the engine that hard with seal material in the oil...

Pat, go play the lottery... You were lucky today.. BUT you paid attention to the forums and did exactly what you were supposed to do, shut the car down immediately, don't try to re-start it and get it to someone who specializes in the M96 engine.

I could be wrong and if I am the test drive will illustrate that later this evening.. Thats why I do things the way I do them.

[BerneseMtnDog]

Makes me glad I replaced my original AOS at 84k when I put in the new clutch and LN bearing. I thought at the time maybe I was being a bit over cautious. Very interesting stuff and thanks for sharing as well.

Steve

[insite]

wow, jake. awesome diagnostic plan. thanks for sharing this; it really does provide insight into the merits of a sound, scientific diagnostic approach versus the shady tree shotgun approach.

as we can all see, it pays dividends, and appears to have done so in this case. nice work!

[Jake Raby]

I'll post when I get home this evening with news about the test drive...

[Pat]

As many others have said...thank you. Great thread everyone, especially JR!