The saga continues! "New" engine blew up!

[The Radium King]

i've read (ie, no ral expereince) that sometimes vehicles will stall with a lwfw, as the ecu anticipates a certain lag in rpm drop when the clutch is depressed. they way i read the initial description, it read like the stall happened when the clutch was depressed, not re-engaged ...

[insite]

Originally Posted by The Radium King

i've read (ie, no ral expereince) that sometimes vehicles will stall with a lwfw, as the ecu anticipates a certain lag in rpm drop when the clutch is depressed. they way i read the initial description, it read like the stall happened when the clutch was depressed, not re-engaged ...

ah; i hear what you're saying now. the revs do drop very fast. in the older cars, if the idle valve is the least bit sticky, it won't always react in time to keep the engine from stalling. i think the e-gas cars don't have this problem so much as the early ones. byron's was e-gas.

i was working under the assumption that the engine died after the downshift was completed. byron?

[Mike_Yi]

WOW! That REALLY sucks!

I'd love to hear the cause of the problem if you ever figure it out. I figured you had covered all the bases with what you've done to your engine. Now that my car is running again, I was thinking about putting an Accusump in it and tracking it again. After hearing this, I'm thinking maybe I'll sell it and buy a used Camaro or Vette.

[seningen]

Well I hope Jake is willing to spread the word.

I'm in the midst of building my Boxster S track car and would
hate to put all that time and effort into it to turn it into a
box of marbles my first time out.

thx,

Mike

[Burg Boxster]

Originally Posted by seningen

Well I hope Jake is willing to spread the word.

seningen,
I think you already have your answer...

Originally Posted by Jake Raby

...I may know what has happened here and I am not willing to discuss it online.

I'm sure this, as you called it, 'box of marbles' is a particularly sensitive subject since it has the "engine saving IMS retrofit/upgrade" . . .

[AndyA6]

This is getting interesting!

[mikefocke]

known failure modes even according to its proponents. This statement is like commenting that the radiator cap didn't save the engine.

I'll be interested in the symptoms of what happened and then we can all theorize on what went wrong and perhaps learn something from someone else's sad experience.

The car was just worked on and had more than the IMSR done to it IIRC.

[seningen]

Originally Posted by Burg Boxster

seningen,
I think you already have your answer...



I'm sure this, as you called it, 'box of marbles' is a particularly sensitive subject since it has the "engine saving IMS retrofit/upgrade" . . .

No Box of marbles is not IMS --

When the IMS goes -- you most likely have bent valves.

Things can get worse -- but on my limited watch -- this is what I have seen.

You can also loose one of the chains, but I wouldn't expect that to be sudden.

Box of marbles -- I'm talking chunks of metal in the oil pan from
connecting rods, cracked pistons, cylinder wall debris.

I missed the original discussion.....

What year/model is the new engine. What is the history of this engine and
what if any rebuild info do we have? --- Ok I found the old thread --- an 02 S
that appears to have spun a bearing or some such and sent the connecting rod
through the block (ouch!)

But I can related -- we just lost #2 rod bearing on our 924S LeMons/Chumps
car. Time for some rebuild and oil mods!

Without tearing it down your new engine -- it's only speculation.

But if its something I haven't seen -- I'd sure like to know about it.
I can't prevent everything -- but I'd sure like to try with in a reasonable budget :-)

Mike

[insite]

engine was an '02S with unknown mileage. it had an LN IMS and a 2qt accusump system.

it has been used on track in the past. the engine was pulled from its original car following an AOS failure that was misdiagnosed as a blown motor.

[Byron in Atlanta]

Originally Posted by insite

ah; i hear what you're saying now. the revs do drop very fast. in the older cars, if the idle valve is the least bit sticky, it won't always react in time to keep the engine from stalling. i think the e-gas cars don't have this problem so much as the early ones. byron's was e-gas.

i was working under the assumption that the engine died after the downshift was completed. byron?

No, it died while the clutch was depressed. I actually coasted the car for a second. Considered pulling to the side, but I didn't want to stop the whole event just cause the car died. So I popped the clutch and engine picked right up. I suspect that the engine died because what was happening had already happened. I never ran a full lap under speed, so I really doubt it was an oiling problem and I didn't over rev. As I said, I was trying to take it easy and bring it up slowly. I had already had it up to speed on the interstate, so I suspect it was a pre-existing issue with the used engine? Obviously, there is no way of knowing if there are internal issues in a used engine without a complete rebuild and Porsche has done a great job of limiting the availability of those.

[insite]

Guide or tensioner failure