Hi I'd like to share with you my issues with this.

I bought the car new in Nov 2010. Since then, I've put 25k miles on it and love every minute of it!

However, there had been a nagging problem that had come up in the last 5k miles or so. The engine will ping, or pre-detonate constantly under certain conditions.

To let you know, I'm a person with a keen sense of detail; however, I am not **** about car-issues. For example, the car has rattled from new, but I have never cared nor done anything about it.

Back to the ping. Under light load, with very light throttle the engine would make a "clacking" sound. It would go "clack-clack-clack"; when I put a bit more throttle it would go away. It didn't happen all the time, but it would do it constantly under these conditions:

Flat road, constant speed (eg 40Mph), constant throttle (of course). If the grade of the road changes uphill slightly, and I try to maintain the speed by adding throttle lightly, the ping will start. I would do it in all gears except 1st. It can be exacerbated by lifting off the gas, allowing the car's speed to steadily decrease and then returning the throttle to catch the car's falling speed back to an increase in speed.

Stepping off the brake and onto the gas from standstill at the traffic lights will do this too - it's almost embarrassing when there are bystanders watching. (mind you, sometimes the clacking and the flat-six sounds similar so I'm not sure if people will actually notice the difference).

Now I know there is ALWAYS some ping to be expected, especially if you are sudden with the throttle. But this also occurred at cruising speed even without increasing or decreasing the throttle.

So I took the car back to the dealer in Sydney (Australia) and the workshop there is a factory dealership (owned by Porsche Germany) so I was sure I was in the right hands. The Head Tech agreed that there was an issue with the pinging so they checked and found an update to the DME software in my car. They re-set and updated the DME software and now the pinging has STOPPED (say, 95% gone). I realize there will always be SOME ping, as the computer can probably advance the timing so close to the margin since it also has full control of the clutch.

Btw, it's not a fuel quality issue as it has occurred for so many miles and I have always used the highest available from main refinery retailers.

Since the DME update last week, I've kept a keen ear to the sound and will probably over-monitor it for some time to come; bummer... It still pings under those conditions but only 'ever' so slightly and very briefly.

I wanted to know if anyone else experienced anything similar?

Howie

 

Please note that the e-gas in these cars should automatically supply the required torque should an uphill start, without any need to change throttle pedal position.

Re pinging... it should not do it, and if I were you I would engage the top tech again to solve, re-check, the problem.

 

Hello. My thoughts: Seems to me that if the car did not ping in 20k miles and is pinging now that it is not normal and something has changed. .2 has a higher compression ratio than previous motor. DFI makes this possible by cooling the cylinder. There has been some talk about deposits on the valves in these motors as a result of the dfi. Deposits in the head would raise the cr even higher. The ECU should be able to adjust the timing to prevent detonation within normal combustion limits. Detonation is not great in a motor that runs hot to begin with. It is the octane of the gas that has to be noted, even if it is from a major distributor (don't know what # you have over there). Were it my car I would motivate the dealer to find the problem. I would not keep this car w/o a warranty out of concern for longevity. I have not heard of this issue on these boards but I would do a thorough search here and on other boards, especially Renntech.org which is technically oriented. Post what you find. Good luck.

 

Keen senses. A true Porsche owner.

U got a lot of warranty left.

 

Also it has been suggested that these dfi motors may need (over time and with milage) to be treated with an engine cleaner to remove built up head/valve deposits of, for want of a better word, sludge. Audi boards have documented this in their dfi motors and there are some really nasty pix circulating. I doubt that your dealer will acknowledge this (or perform the cleaning) but it may be worth looking into if nothing else surfaces.

 

Let's not speculate... we do not know what causes the ping. No 9A1 engine was shown to develop intake tract gunk. And there are many cars with far more than 20k miles running perfectly.

The 'nasty pix circulating' is an early DFI cayenne engine. It is NOT a 9A1 engine, which has a very different design. The 9A1 engine is proving to be a very solid power plant, but in spite of that, many are expecting it to fail spectacularly. No, the sky is not falling...

 

Thanks to all for the comments and thoughts so far. I would have the following to add:

Speaking with the technicians and service managers, it would appear that my car is probably the one with the highest mileage on their books. Maybe they don't have the experience in regards to the DFI motor?

I will look into the suggestions you have put up and continue to (over) monitor the ping if it gets worse... But while I was doing other crap at work, I decided to 'picture' the issue by drawing it; a graph I dub the-ping-o-meter!

Hope it makes sense...

Thanks!
H.

 

Normal/Auto, Sport/Auto, Manual...??? Or all?

 

As I said... Check your e-gas. E-gas in a 997 is designed to regulate torque. It appears your throttle doesn't do that.

On DFI... Ignore the 'sky is falling' naysayers. The gunk they are so worried about and which no one ever saw on a 9A1 engine is soft stuff that would deposit behind the intake valve, not in the combustion chamber. It would not cause pinging.

 

I have a 2008S with about 6000 miles. I generally drive with the windows closed. I have noticed the pinging in the summer on theose resre days I have the windows open. It happens in the +/-2500 rpm range only when cruising under light throttle and then adding a bit more gas. It doesn ot happen iwhen cruising and then lifting off of the gas a then stepping on the gas again. This tells me it it how the computer ins managing the ignition timing which often uses vacuum as the input. It seems the computer is a bit late in retarding the timing when increasing power after cruising.

 

i may be totally off-line here but next time try to put in 5w50 mobil 1 oil instead of 0w40 and check if that ping will go away.

 

ALL, but worse in AUTO.

 

How do I check that?

When I was trying to figure out why it was pinging I came up with various theories:

1. Calibration of e-throttle; ECU not seeing what it expects from throttle, controlling fuel & spark. All the throttle does is actuate a set of electrical contacts or deflection in a servo motor which then sends a voltage to the 'puter.

2. Throttle body controller; but I suppose they're controlled by servo stepper motors with a decent degree of feedback or open loop power?

3. Fuel injection; but all controlled by ECU which then I realised this when the tech saying that the DME needed updated software. Now this then begs the question: How did it deteriorate?

Yes mine did that, but much worse. The season is changing cooler here so the variances in temp (i.e., O2 density) affecting the air doesn't matter in this case. I'll also mention that on start-up when the engine is cold, there is no ping whatsoever because the fuel-air mix is rich to heat up the engine & cats. I also noticed that sometimes on the start up engine rev, it will sometimes ping on the rev-down (all happens in the matter of seconds)

Now that the DME has been updated I checked it again on my way home from work today. I was on the freeway with the window down to see if I could re-produced the ping; yes, it still pings under the same conditions but now much less. It does it especially when being lugged in a tall gear, like 7th@71km/h. I think this stupid PDK is half the problem: why on earth does it have to grab the next bloody gear as soon as it can? FFS it's a sports car, not an econobox! If a customer can afford a Porsche then they surely can suck it up and pay a bit more for fuel!

I think I will report back to the workshop with my findings.

 

Could you explain your reasoning here ?

 

not much of a reasoning there.

but heavier oil may have less chances to get into cylinders in amounts 0w40 does. plus 'pinging' is quite a broad term, if it is indeed a detonation I would say it is not very common so it got to be a reason. to play with oil a bit is an easiest thing to try.

I had an odd engine behavior may be once or twice but each time i simply did ECU reset (power off battery for 10 min) and it was gone - i suspected bad gas in both cases.

if you do have traceable repeatable detonation they should run car on a dyno with PIWIS connected and get sensors data to find out why it happens.