lucxy

How to reset misfire codes on a GT3? I tried OBD2 scanner to clear the codes and it it did not work. The codes still show up and a yellow warning light to visit workshop on display (drive permitted). Car drives fine without any problems. Codes appeared during oil overfil. Oil was drained within normal level now but codes are still there? Any ideas how to clear them?

neanicu

First post the codes.
Then,if the oil has been overfilled by a lot and engine had been run,you might be looking at a whole lot of problems now. The oil can end up in the intake,air filter etc. The codes might not be able to be cleared because the problem is still there,it's a hard fault.

lucxy

P0300, p0301, p0306, p0302, p0304, p0303, p0305, c1555.

neanicu

Yeah,that's bad! You have misfires in all cylinders. This can't be related to a bad coil,plug or fuel injector. Those are fouled spark plugs by the oil excess. Who did this job and overfilled the engine?
Do not drive this car,do not even start it! Have it towed to the dealer.

lucxy

The codes poped up during oil change, the motor was shutdown immediately, oil drained and refilled. Since then car no longer misfires and runs. But the codes are still there. Is there a way that the motor is no longer misfires but the code are just stored and cant be cleared?

neanicu

Just because you feel that the car is running better,it doesn't mean that the car is not intermittently misfiring. You need to look at Mod 6 data and check the misfire counters for each cylinder. If they're not 0 on each cylinder,then the computer sees a problem and you can't reset the check engine light.
It's enough to run the engine for a minute to get oil into the intake,throttle body etc. I believe this engine is measuring air density using a MAP sensor and not a MAF. The MAP is manifold absolute pressure. If that sensor is full of oil,it will completely mess up the air readings and the computer won't know to adjust fuel.
Also the plugs might be fouled with oil and they need to burn the extra carbon deposits off.
How much has it been overfilled? A little is ok,but if we're talking almost a quart,you have a problem.
The codes are stored as a hard fault. You can't clear a hard fault until the computer had run a drive cycle and " it's happy ".

lucxy

I c, how long is the drive cycle? Not sure what mod6 data is. How can I look up misfire counters using OBD2? Possible? It was overfilled by a few oz I think and it ran (idle) only a few seconds in misfire mode. I am keeping my fingers crossed.

neanicu

It depends on the scan tool you're using. It needs to have live data,but I highly doubt a regular OBD2 reader most guys are using has Mod 6 that reads a late model Porsche.
Good luck! And since you are not sure by how much it has been overfilled,please do not gamble. That engine costs...what...50K?! They won't replace it if they discover you messed it up. Better safe than sorry...

MileHigh911

Was it a DIY oil change? The sensitivity to overfill has been well discussed on RL.

lucxy

yep. I did not realize how easy it is to overfill the oil. Damn. Will bring the car to dealer. I wish there was some simple way to check oil level instead of relying on the electronics.

Jimmy-D

I only have the Dealer fill my oil.

They top it off for free when ever I need but even they are very cautious and told me it is so darn sensitive

lucxy

I think that there should be a fail-safe system to handle oil overfills without causing engine damage. The same thing with my C6 Z06 with dry sump -- no gracefull way to handle oil overfill. I would think that all that german over-engineering should have anticipated overfills and handle it a bit more gracefully -- even dump it externally somewhere or something. People make mistakes including techs @ dealers. Seems like a very simple mistake to make that can cause a really bad outcome. To be honest I dont trust dealers either, many are rushing jobs and dont pay close attention to your car -- mistakes are bound to happen.

neanicu

It's the reason Germans are accused of over engineering. It's true in most cases. What was wrong with a dipstick? Absolutely bulletproof!
But I will again say it,with the fear of being accused of spreading conspiracy theories : the dealer network around the World are pushing manufacturers to make unnecessary complicated systems that can't be service by Joe's garage in the corner or DIY. The Service department brings the most income in a dealership,not the sales or the parts departments. It's a statistical fact!
The result of making over engineered systems is that in most cases,expensive tools and computers are required to service these cars.

To get back to your case and to prove my point,a dealer technician would not have most likely overfilled the engine because they are using their 20K $ PIWIS factory scan tool,that can access the oil level sending unit through the car's DME at any time : with the engine hot/cold,key on engine off,engine lid open...whatever situation which otherwise DOES NOT work for a simple DIY-er.

MileHigh911

Keep us updated on what happens. My guess is they have a protocol for when this occurs. Besides hearing about some that had to have oil removed, I have not heard of the "hard codes" lasting like in your situation. Good luck. It is just a car.