Shane911996

I am looking at purchasing a 2007 911 997 Turbo Coupe and looks in great condition (and I know the current owner was fastidious about its maintenance) but the pre purchase inspection has revealed some bore scoring. I thought the Mezger engines were supposed to be immune from bore scoring. Is this something I should be worried about? Feedback would be appreciated as I am at the decision point in the deal.

snolvr

I might be inclined to question the validity of those findings. The Mezger used Nikasil plated cylinder linings which is vastly more durable than the sumbore lining used on non-turbo 997's. Does the car exhibit any strange symptoms? Does it smoke or burn oil? I guess the next step would be a compression and leakdown test if the car does in fact have symptoms. Any additional information would be great.

Shane911996

Thanks for your response. The car doesn't exhibit any strange symptoms that I have noticed (but only seen the car once) I didn't notice any smoke on start up but it did have a warm engine. I have had a leak down test completed as well and it reveals leak down of between 4 and 7% over the 6 cylinders. The overrevs counter shows 1 overrev in Ranges 4, 5 and 6 which means it reached over 9000 revs at one stage (for a fraction of a second) and it occurred over 500 hours ago. The PSI tests reveal between 205 to 210 psi with a dry test and 210-215 PSI with a wet test.

lliejk

Get them to email you pictures of this "bore scoring".

Ed

Shane911996

Here is a video of the bore scoring

Johnny DB

The 1 over rev in range 4,5,6 is a glitch.

snolvr

Hmm.. not an expert here by any stretch but that looks more like pitting than bore scoring to me. Leak down and compression numbers are spot on for a healthy engine. And agree with @Johnny DB that 1 overrev is impossible. It's actually 1 ignition which can't happen because there are at least 3 ignitions with one revolution of the crank. Even if, it was still 500 hours ago.

signde

+1, single overrevs like that are a known glitch we've seen numerous times. i'd buy that car and send it, assuming everything else checks out.

also be sure to budget for eventual drop engine and pin all the things maintenance, which can be an expensive job.

Jaskfri

I had bore scoring in a 20006 911S. it did not look like that. That looks like some kind of pitting issue. I am not an expert in Internal metallurgy. Have someone knowledgeable look at this before you buy it ..

Shane911996

@snolvr @Jaskfri that is what I thought too at first but after speaking with the mechanic (who is a very experienced Porsche mechanic) he told me that it is just a bit of carbon that came off the valves when he did the leak down test and the PSI test and after looking at all the video of all the cylinders the "pitting" (carbon) is only where there is a bit of oil in cylinder where he injected oil to do a wet PSI test.

slm181

This.

I’d be more worried about the state of the coolant fittings and wheather the intake cam shafts have been pinned or not. Hopefully this has already been addressed on the car you’re looking at. If not, have a healthy chunk of extra cash on standby. See my thread on catastrophic coolant loss for an idea of what I’m talking about.

JoyPorsche

Curious to know how they put in camera in there. I would like to know. Thanks

Shane911996

They stick the bore scope down the spark plug hole

JoyPorsche

Thank you for letting me know

TRINITONY

@Petza914 your thoughts? In our cars that would be considered the beginning stages, but they're known to score.