Tiptronic shifting to 3rd gear and engine goes off

[gizlaroc]

Yeah it is the 722.6 transmission in the 997.

Is the OP 100% sure the filter is fitted correctly?

There have been cases were the sump gaskets age and let water in, which blocks the filter and will cause the exact issue he has. It starves the torque converter piston and you stall.

I can't see how there would be an issue fitting a new filter, but maybe something was down the neck and it causing issues?



What on that list was done since the car was fine and the issue? That is not very clear.

 

[Erik997S]

Thank you all for your replies. I checked the gearbox oil level again, and it seems fine. I added some extra ATF, and a bit came out, which is normal. When the engine runs, the pump pulls the ATF through the filter, which is how you fill the ATF. If you stop the engine, ATF should come out through the control bore, and it did—so far, so good. But the engine still shuts off when shifting into 3rd gear.

I also tested it without the airbox, but there’s no difference. I still have negative pressure, which is necessary for the flap in the airbox, and the MAF (Mass Air Flow sensor) is giving a signal as well.

I spoke with a gearbox specialist with over 40 years of experience, and he’s never heard of a gear change causing the engine to stop. He believes the issue might be elsewhere.

As a last attempt, I’ll try disconnecting the immobilizer from the anti-carjacking system. Unfortunately, the company that installed it is no longer around, and I can't find any information on it.

If that doesn’t work, I’ll have the car towed to a Porsche specialist.

 

[Erik997S]

Yeah it is the 722.6 transmission in the 997.

Is the OP 100% sure the filter is fitted correctly?

There have been cases were the sump gaskets age and let water in, which blocks the filter and will cause the exact issue he has. It starves the torque converter piston and you stall.

I can't see how there would be an issue fitting a new filter, but maybe something was down the next and it causing issues?



What on that list was done since the car was fine and the issue? That is not very clear.

For clarity, before making all the changes, there were no issues with the car.

 

[gizlaroc]

Sounds like it could be the torque converter locking up.

If you start in sport or manual mode, you start in 1st, does it then stall when it tries to go into 2nd?

Trying to work out if it is 3rd gear that is an issue or any gear change at all.

This is important.

 

[Erik997S]

This is important.

Sounds like it could be the torque converter locking up.

If you start in sport or manual mode, you start in 1st, does it then stall when it tries to go into 2nd?

Trying to work out if it is 3rd gear that is an issue or any gear change at all.

I can shift from 2nd to 1st and back to 2nd without issues, but if I don’t press the accelerator, the engine starts to stutter. It feels like it's not getting enough gasoline.

 

[gizlaroc]

And is it the same if left to idle so it gets to temp?

So left for a good 10 mins?

 

[Bigbaddog997]

Can I ask if you have any updates on this issue? Just asking out of my own interest.

 

[Erik997S]

Sorry for the late reply. We finally found the issue! It turns out that because my battery had been dead for so long, the anti-carjacking system got stuck in a loop. Since it was an old system and the installer no longer exists, I had to find a professional to help me sort it out. Everything was working fine until 60 miles later, when a coolant supply hose burst. The car had to be towed back, but I ordered the part and installed it myself.

I guess it’s really not good for a car to sit idle for a few years!

 

[Bigbaddog997]

Thanks really interesting.
Whilst I was convinced it wasn’t the gearbox, I genuinely thought it was going to be a fuel pump issue!