Would anyone else be concerned about the technical skill required to swap a 991 engine. I am sure the dealer techs are very good, but that is like a physician watching a video of a major surgery and then having to do it live and without help. I think I'd be a little nervous..
J

 

Not at all. Plug and play.

 

If you want to see open heart surgery on the 991 motor, go read the recent thread about the PowerKit installs. That's major. An engine swap, no biggie.

 

I did ask if Porsche could ship us a complete X51 engine and the answer was no.

Good info - thanks. I wish I had a spare 15k to have them install the X51 during the swap. Ahwell.

 

I guess I was just thinking about that 'how they make a 991' video, where those smart looking German boys are 'mating' an engine/transmission with a chassis. Trying to picture that in my local Porsche dealership, used to doing expensive oil changes and details.
J

 

Car back today! It's actually smoother and sounds as good as before. She's perfect. They don't know exactly what happened - Porsche gets to find out though. Wish to be a fly on the wall for that. anyway whewwww!

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Great to hear it all worked out well!

 

Whew!

 

thanks Darren. Apparently there were lots of metal shavings in the oil filter (the service papers read "full of metal") when they investigated the strange engine sound, and that prompted the diagnostic back-and-forth with Porsche which resulted in the engine swap. Wild, but understandable Porsche wants to examine an early engine of a newly released car series. Anyway, all good.

 

nicoli, strange finding. let us all know if they ever update you further on this. i think we are all curious! glad it's all fixed.

 

Thanks oldman. I didn't want to turn this into a circus, hence my hesitation describing things further regarding the sound. Now that I have the car back and in perfect working order, I'd describe it as a knocking sound that suddenly became very audible. Chuck911 messaged me privately at the beginning of all this - saying if it was a knocking sound, his bet was on main bearing failure. It was exactly that sound, and with heavy metal shaving or debris in the oil filter. That's all I know. The SA advised me he would inform me if or when he knows more. I'll pass it on if or when that happens. Best wishes guys and thanks - amazing to drive her today. So smooth! sent with iOS using Rennlist

 

Heh, that was the Walter White in me coming out again. A fairly simple deduction really. Was not expecting metal shavings though. In hind sight probably should have. Anyone who has seen these engines torn down up close will be amazed at the close tolerances. I'm not talking about the 0.001" tolerances of main bearings but how close parts like connecting rod journals fit next to main bearings, or how little clearance there is even from the head bolts that fasten those con-rods come to other parts of the case. It looks tight even on those videos, but if you see an engine and look closely while turning it over by hand there are lots of places where parts are moving very, very close indeed. Like, you could slide a piece of paper between them- barely. Now when a main bearing "goes" enough to hear the knocking sound this indicates the crank is moving back and forth and knocking against the sides of what is supposed to be a perfectly round snug circle. But I guess if it can move around enough to cause knocking it might also move around enough that the crank shaft (carrying the con rod journals) allows those parts to interfere with (i.e., scrape into) other parts.

The million euro question Porsche is no doubt investigating is: chicken, or egg? Was it main bearing failure that caused the metal shavings? Or metal shavings that caused main bearing failure? And if so then where'd those come from?

Incidentally, what you know and others don't, is how I reasoned it out that there was likely a knocking sound in the first place. (Because you were very careful and never said a word about what kind of sound.) It was simply that nothing else but this would merit a full engine swap. Whatever it was had to be within the case. Within the case the only thing one would hear is main bearing knock. Now… My favorite 30 sec of my all time favorite show… say my name….

 

thanks nicoli, your update much appreciated, i'm sure by all on the forum. good call chuck911...deserved props to you!

 

glad to hear your back on the streets...........now if we could only get one day of good weather for some topless motoring!!!!!

I'd like to start up our monthly 100 mile tours again with our wild 991 friends from Canada soon. I need to check if a Boxster S would be ok to tag along

Hope you can make some this year.......looks like there is someone in town with a X51 also.

 

Porsche will not be telling anybody what the failure was. Well, not any of us.