Hi
Car was checked by an indie.
Agree after 8+ years numbers of problems are thankfully low.
Engines have thus far proved to have good reliability.

As for other symptoms on my car - oil use was the main one, VERY sooty exhausts, beyond normal DFI soot, all the time even after a long run. Guess the oil is getting past the piston rings.

The number of other owners who have had problems has been in single figures, not even 10.

reason I advocate a new owner having full PPI is that repairs can be very expensive on Porsche's so why would you not spend less than 1% of the cost of the vehicle to have the peace of mind its all good?

Happy motoring
Glen

 

I agree that these engines are much better than the M96. Instead of 29 documented modes of failure (24 of which I had identified before the engines were at their 6th year in service) we only have 7 documented modes of failure for the 9a1.

We still have a constant flow of 9a1 engines coming through Flat 6 from this era, but about 1/3 of those are elective builds, where owners want a hand built engine thats application specific, and they have not had a failure. I'd say that within the next year the 9a1 based builds will supersede our M96/ M97 based built in terms of volume through the facility.

In the early days of our 9a1 program we only built 5-6 engines per year, and way back in 2010 we only found one guy crazy enough to send us his 997 with 11 miles on the odometer to have the engine pulled apart and built into my 4.2.... We like crazy people.

One ancillary item is greatly contributing to cylinder failures in both series of these water cooled engines. I'll be sharing more about this as soon as I gather more data in a manner that can't be argued with.

 

I agree. I wouldn't take any advice from a service advisor that didn't noticed the difference from a .1 and a .2. Additionally, car dealerships love to get your money from unnecessary treatments.

 

I haven't seen one thread on this site where someone had carbon buildup on a 997.2 engine. Am I missing something? I had an S4, and I swear every third thread on the Audi board was about carbon buildup. I never see it here.

 

I don't think you've missed anything. The only thing I may be minimally concerned about regarding the 9A1 comes from a trusted source via PM, based on a motor rebuild course he attended ... the cam chain tensioner may need occasional adjustment. I'll let him expand on this topic should he feel it is appropriate.

 

Any idea what the symptom would be if it needed adjustment? I assume there would be a CEL if cam timing was off.

 

I imagine rattling or ... But please don't take my word for it.

I was not in the class and while I felt, for thoroughness, it should be mentioned, I'm not qualified to discuss it.

 

Is it adjustable? How would the cam tensioners be adjustable?

 

I don't think the statement above is correct with regard to bore scoring. The coolant manifold was redesign to provide more even cooling to prevent/reduce scoring.

It was generally accepted that local hot spot has a significant part in bore scoring (after all, it often show up on one set of cylinder first).

Please provide reference indicating that bore scoring is the same between 97 and 9A1.

EDIT: I just read all the posts after put in my $0.02. No need to reply.

 

I'm Wayne's source and there was/is some concern about the timing chains in the DFI motors being made more lightweight, which could mean that they end up stretching or breaking over time. But, to my knowledge, this doesn't seem to be a major issue and DFI motors do seem to be holding up very well. Replacing (not adjusting) the chain tensioners on a PM schedule might help prolong timing chain and consequently engine life, but with guys like Bruce & Wayne with lots of miles on their motors, and no major issues to report, that PM replacement interval looks like it can be pretty high - maybe 60,000-75,000 miles to be very conservative.

I believe Jake, in some different threads, mentioned that he's seen about 4 dozen 9A1 motor failures come through his shop, but I don't know the failure mode distribution on those - certainly there have been a few with bore scoring as documented here on Rennlist directly by their owners or by someone who knows the owner personally, so that possibility still certainly exists in the 9A1 motor, even if a remote one.

Also, bore scoring might to some degree be tied to climate and possibly region of the country where winter blended fuel formulations can be different from one another, and when a really cold morning is combined with a certain winter blend fuel, they sum to cause the issue, but this is still very speculative and there are probably more contributors than just these things or it wouldn't happen in places like San Francisco where it doesn't get extremely cold.

Anyway, to the OP, with the number of hours on the car you're looking at since the Range 5 overrevs and if compression and leakdown look good, I don't think you have much to worry about.

 

Back on topic. What are the failure modes from over revs? Back in my motorcycle days, we worried about floating the valves. Then it's valve meet piston and instant failure.

 

Possibly something like this:

 

Never heard or read of one.....

Peace
Bruce in Philly

 

Looking at the back of my 911 it's hard to tell if it's .1 or .2. I cut the guy a break.

 

You're a better man than me. The inside angle of the tail lights gives it away.

And I still wonder what his diagnosis was based on.

And has he done this procedure before?

I guess if he cut his teeth on BMWs and was new to Porsche I might better understand. But I don't even know if Porsche has a method for cleaning. It was suggested earlier that this would need to be a motor out service. It seems that no one here has needed this.

Just saying. Have a great 4th ... you've earned it!!!