Gents - sorry for the delay here. I've been remiss in not answering questions. The noise, strangely, faded somewhat after a couple of weeks. Now, it is still there, but less prominent. I have taken it to a shop that has come highly recommended and will share result soon, but it appears that, while the sound is/was quite foreboding initially, it is not in fact bore scoring. Not trying to create suspense here and apologies for misleading anyone - I was very concerned when I heard that sound! Nobody is happier about this not being a case of bore scoring than me!

 

Turns out the sound is attributable to the high-pressure fuel pump. Has anyone ever heard of this? I listened with the mechanic's stethoscope at the shop to each cylinder bore and each sounded very smooth...he had me go through each one with him, and after listening all over had me listen to the HPFP - bam! Clear as day, the sound reproduced to a T. Needless to say, huge sigh of relief. He said (and from what I've read) that soon I may notice hard cold starting etc and to plan on replacing it in the next few months before it becomes an issue. Charged me very little labor as well. Anyhow, I now have a warranty on the car so the question is whether the warranty will cover it as it hasn't yet failed or if I will be required to have the car on a flatbed before it would cover the fix.

Consider me surprised, and a little sheepish.

 

Oh wow, what a story. That is great it is not a big problem, and hopefully this thread will help others.

i guess you dropped 3k to figure it out .. just goes to show how critical it is to get to the right mechanic and first time

 

What I find interesting in this entire thread is how the diagnosis of the problem followed what we might call an "understood trend".

1) Weird sound.
2) Uh-Oh...sounds like piston slap! OMG....that's not going to be pretty. [at this juncture we inject the time stress from the 'warranty']
3) Got to bore-scope.
4) Should bore-scope from bottom.
5) Top showed nada.
6) Bottom showed nada.

Lived with it.

Wise mechanic uses one of the least expensive, non-invasive tools in his kit and locates the noise exactly.

Yep, a lesson here. Somewhat happy ending.

 

This. Could not be more true.

 

Great points here - and you’re spot on. Rather than follow a normal diagnostic paradigm I jumped to what I feared was wrong (to be fair, the first mechanic also suggested this was an internal engine issue). Anyhow, somewhat happy ending as you say - more expensive than I’d like, but less than an engine rebuild!

 

Don't beat yourself up--the pressure of the time constraint (warranty issue) would have made us all do exactly what you did

 

Glad it all worked out. Now can we change the title of this thread?

 

If you can change the title of the thread you can prevent others from jumping to this same conclusion

 

I'm far from an expert but my understanding is that the HP fuel pump is a typical issue with DFI cars not just Porsche DFI.

 

Yes I agree - it's a known issue and some of the earlier cars had more of an issue...I was referring not to the failure but rather to this sound associated with such.

As to the renaming of the thread, I'm not sure how to do that, but I could definitely be in favor of something like:

"When bore scoring isn't bore scoring; Or, How I learned to stop worrying and love the car"

 

Gawd I hate reading threads like this, makes me stressful and nerve racking. I am very glad it wasn't bore scoring and yes the high pressure fuel pump failing is quite common on most DFI engines. FYI the title of this thread still have not been changed. Hope you are enjoying your 911.

 

Reminds me of a friend when I was a kid. He was worried sick that he got his GF pregnant when she threw up and having a stomach ache. He was all prepared to marry her and break the news to her parents. Later on found out she just had a case of indigestion, Talk about being born again.

 

Hope you are enjoying your car

 

I'm not sure how to change the thread title - happy to, if mod can assist? "When 997.2 bore scoring isn't bore scoring"?