Bruce In Philly

2009 C2S 193K miles

Anyone actually see carbon buildup on intake valves in a 9A1 .2 engine? Details?

Given the miles on my engine, being DFI, and hearing about all these makers out there with problematic DFI engines, I gotta wonder. Anyone use those treatments you blow into the air intake?

This topic pops up every once in a while and as my car gets on in age and miles... knocking on that big 200,000 thousand mile mark... feels really weird to write that all out like that... I thought I would ask again. There was much speculation on how Porsche has avoided the problem with those diagrams out there that imply the injectors are spraying a bit on the valve top... or the articles that imply that the injectors are actually spitting a bit of gas out when the valve is open... all speculation but no hard facts.

Just for the curious, my engine runs fabulously. Really smooth.... just great. I still have that odd suckout at around 2.7K RPM where we think the variocam is activated but that has gotten very less over the years and miles... still there but no so jerky. I replaced the throttle body when I could not get a steady idle and its replacement not only stabilized the idle... rock solid even today... but smoothed power delivery overall. No position sensor failure, MAF failure, or other sensor failures.... just rock solid engine performance. I can go on about other engine issues such as a failed coil packs, water pump and leaky power steering pump I replaced (I suspect from the factory), but honestly, if this is all I did over those miles... not bad at all. Noisy? Yea, this engine ticks and tacks and has done that since new but if it were something wrong, it would have broken by now so I think. Oil consumption is up a bit... so hard to remember.... but maybe from 1.25 litres per 5K miles to maybe 2 litres per 5K now... or less. Blackstone oil analysis are stellar. Mobil 1 0-40 for 2/3 of its life, now Liquimoly 5-40 with Ceratec... A heavy bottle of Techron every once in a while....

Not much to worry about so.... what about that carbon buildup ? ! ? ! Ahahahahah!!!! (need something eh?).

Peace
Bruce in Philly (now Atlanta)

Wayne Smith

Just another benchmark ... 2010 C4S PDK at 154K miles.

All original parts with the exceptions of ...

Motor mounts ... helped cornering stability.

Trans bushings ... Because the motor mounts helped.

Front computer ... Because of weird hazard flasher behavior. Since then, it was pointed out that maybe reprogramming would have fixed this.

Top front strut mounts ... Because AWD.

Left front axle boot ... Miles and miles of chip seal in Idaho.

Still on original water pump, idler pulleys, expansion tank (and cap), and anything and everything else. Still runs great, although mpgs may be down (hard to tell now that I'm not commuting).

Oil? Mobil 0-40 for 140K miles, no additives. No oil burning ... 7.5 quarts out, 7.5 quarts in, no adding in between 5K mile changes. Then I switched to Liqui Moly 5-40 with a can of MoS2 (I was bored). Burned a half quart in 5K miles after the change ... first time. No burn on this second Liqui Moly fill. I never run oil to the top bar!!!

Plans? The original suspension could be refreshed. But for the cost vs. miles per year these days, I'm holding off. The car still does what it needs to do on our spirited drives. How much more could I ask for?!?!?!

Bruce ... Kick back and enjoy 😉

Floyd540

We have said this before, for a good quality German car 200,000 miles is just approaching the haloed status of high milage. Very high milage status is a long way off. Every one of my VW, older BMW's went to over 350 to 400,000 miles and when I sold them they ran forever for the new owner.
Except for the fiddley stuff the 997.2 has proven to have that classic 911 reputation of being bullet proof. My 2011 C2 stick shift has only 103,000 miles and the only thing that has been replaced other than standard maintenance itemsare the coil paks at 98,000 miles. They are cheap and DIY anyway. The car has, is and will be terrific probably forever. Keep driving your car as any newer model has lost almost all of the 911 DNA that some of us were raised on. They are even putting "911" emblems on some of the newer models to try to make people think they are 911's, but they are closer to a Buick.
Keep driving your car, it is a good one and it has proven that to you. No worries.

silver_tt

I know the thread you mean but I don't think the fuel is hitting the valve, that's just a bad illustration. Skip the spray cleaners you blow into the intake. Carbon build up on the intake valves isn't great but in most situations it's not the end of the world. Next time you have to take the intake off for any reason have your indy walnut blast it, this is the best solution. In the meantime you can use an oil with a low volatility and there will be less oil laden air. Your car has almost 200K miles on it, I don't think you have anything to worry about unless you want to -- your "need something eh?" cracked me up haha

mk85911

Good to see such longevity. I purchased my 2011 997.2 MT new with the hope of getting 25 years out of it because I figured that was about as long as I could expect to live. My 1985 911 was about 25 years old at that point, and although it was and continues to be bulletproof, I wasn’t so sure I could get another 25 years out of it, but I might.

I made my move when information about the next generation 991 was becoming available, and I concluded that the 991 was moving into grand touring territory, and I didn’t want that. I couldn’t be happier with my pick of the 997.2; an absolute joy to drive , still old school Porsche, and, so far, other than one coil pack, bulletproof.

I don’t have anywhere near the mileage you guys have, only about 54,000 , but I did something recently that should increase my usage significantly; I mounted all season tires so I could get another three or four months usage each year during the cold months, and I’m already getting more usage. I mounted Michelin AS4s, and , looking back, I was kidding myself that I needed ultra high performance summer tires—the Michelin AS4s are extremely capable.

Mike

Petza914

I specifically asked Hartech about that injector spraying on the back of the intake valve thing and they said, no, that doesn't happen and the graphic is misleading, so no idea why the Porsche DFI engines aren't plagued by the same carbon build up as BMW, Audi, and other DFI motors.

The engine builders had some concerns about certain areas of the 9a1 motor when it debuted, but the engines are holding up great in general.

silver_tt

Agree and if you think about it, it wouldn't work having the injector spray onto the top of the valve when it extends anyway -- it would completely mess up the spray pattern which is critcal for DFI. 9A1 definitely gets some carbon build up based on engines I have seen but nothing to worry about and I agree that it's a durable engine overall capable of doing high mileage.