What could it be? i cannot get above 1.1 -1.2 bar in 2nd before i use to get 1.4 bar at 4500+ rpms , 3rd boost is 1.1 , 1.2 all the way to the limiter , 4th the same but goes to 1.2 - 1.3 briefly..... all of this happend a sudden after did a 0-300 run .. at first i though it was iats , so i let the car cool down... but the ambient was 25 degrees!!! and my car was hitting 4000+ to the limiter on 2nd 3rd 4th 5th and 6th 15 minutes before the run!!!

This morning i tried the car and it still has the same problem i took it to the dealer they did a quick check on the hoses and did an obd scan and no problem!!
i thought maybe because maybe the gas station attendant filled my tank with the wrong gas 90 octane europe!! so i filled the car with 97 octane and ran it for 60 kilometers hoping the problem would dissapear but it didnt..
what could it be?

 

I would suspect boost leak. Have the dealer pressurize boost hoses to about 20 psi. You can hear leaks at that pressure. Find them and fix them. Boost leaks typically occur while you are pushing the car or if you work on the car and dont get something tightened down enough. The dealer should know how to perform test and have proper equipment.

 

my guess is that it's a loose hose. Happened to me already with the IC hoses. Good luck and keep us posted.

 

GTDeux , when the iats are high , it is detected by the knock sensors instantly , and thus adjusted when the temperature changes , i did lots of data logging on this aspect on my 997 ruf 600 turbo , where ambient temparatures were 45 + degrees , and iats were creeping above 85 degrees...

i do agree that its a combination of factors , maybe fuel , loose hose or the acuators stuck...

will keep you all posted

 

Have your dealer to look for fault codes for the Turbo High Temperature Sensors.

When these go bad your boost pressures will be all over the place.
When the sensors go bad one time they will not come back.

Tomorrow mine will be replaced for the forth time. My dealer is going to order a set to keep in stock for my GT2.

My turbos are not running hot, my motor is not running hot, my oil temps do increase but not over stated limits.

I think that the sensors are not up to the task and need to be improved.

 

Hope you get it fixed soon

 

Put a dataloge and look at the IAT and the boost then compare.
I faced the same problem but when i used the dataloge i've seen high IAT when i loost the boost.

 

Guys the problem is consistent even the second day and it is not due to the iats , i checked it via obd and there is not a fault code , it is more likely something mechanical , such as the acuators or the boost hoses or the TB.

i will take here to the dealer tomorrow

will keep you up to date.

 

try to reset your ECU and see if that help. I know it sound mechanical more than electrical but it wouldn't heart to unplug you ground during the night and check the car next morning in your way to the dealer. good luck bro and keep us updated

 

Just got back from track weekend at Road Atlanta.

We picked up our GT2 from the dealer Friday afternoon and went to Road Atlanta with it and our Z06.

Saturday morning after putting on track tires and setting suspension for track driving I took the GT2 on infield road to check if boost would come up. As soon as I hit the gas the boost went to 8psi. I knew that the new High Temp sensors were working.

Two days and 225 miles on the track the boost never failed to max out 20psi under full throttle.

As I pointed out in my previous post this is the forth time that the Turbo High Temp Sensors have been replaced. When they go bad the boost is all over the place except for 20psi. After the next track event they will have to be replaced again.

The problem is in the sensors, Porsche needs to buy a higher quality sensor.

 

Do you get an engine fault code or do you look for low boost with NO Fault codes recorded..before changing them... there is two sensors?

 

Fault codes are present. Our service department had to drive the car with their computer pluged in the first time to find fault codes, now they know where to find fault codes and clear them out when the sensors are replaced.

The correct part name is EGT sensor, Exhaust Gas Temperature Sensors. The two sensors are connected to the same plug that is connected to input at top left of motor.

I have been told that 200 cell cats could help solve problem. Maybe but a $200,000 car should not have this problem. If the sensors cannot handle the abuse then they should be redesigned.

Try going down turn 12 at Road Atlanta and have the boost to go to zero. Or spend the money and time to go to a DE school and have the sensors go bad after one session, makes for a boring weekend.

No way to tune engine knowing you will have to return to dealer when sensors go bad.

I still love the car but not pleased with problem.

 

I rolled on the throttle..it quickly went to 1.3 ..have over 4k miles on it with plenty of track time at Mosport, plenty of power on hand?!

 

*Update*

As i drived to the Porsche dealer , i ran the car to about 130 mph , and nothing the problem is gone. i guess this was after i left the car untouched for 3 days in the garage.

Porsche checked all the housings did a obd scan and made a test drive with there test driver, nothing was detected.

As i took the car back home, i i ran it a few times till about 130 miles , i encoutered the problem once and was very disapointed.

later at the evening i did 2 0-190 mph runs , and the problem is gone , 1.4 bar all the way to 190mph

I guess afterall it was a fuel problem as i guessed , and the cars tank still has some residue of the low octane fuel left so thats why it acted like that breifly today.

i'am going to fill the car with high octane pump fuel and we i will do a few runs and let you know.

This is a lesson to not let a gas station attendant fill your car with gas, and if he did double make sure that he is putting the right gas !!!!!

 

Good thing it was an easy problem to solve...much better than something wrong mechanically