997 Turbo MK2 - misfiring cylinder 4 5 and 6

  • Hello everyone!

    Our 997.2 Turbo (year 2010) currently has a problem with misfiring on cylinders 4 to 6.
    The vehicle runs relatively normally while driving when warm. When stationary (especially after a cold start) it runs slightly out of round.
    We became aware of the problem because the MKL lights up after approx. 15 minutes of driving and the following errors are displayed:

    - PSM failure

    - Engine diagnosis workshop

    - Start-off assistant failure

    We then read the vehicle with a Gutmann tester and detected misfiring on cylinders 4 to 6. We then monitored the misfires while the engine was running and saw that it had a total of around 100 misfires on these cylinders within 10 seconds.

    Our first suspicion was, of course, the ignition coils. We then replaced them immediately and also replaced the spark plugs. These were still in good condition.

    Has anyone already had a similar problem? The Gutman tester shows no other faults apart from these.

    Many thanks for your help!

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  • What exactly does the Gutmann tester say?

    Was or is an exhaust gas measurement carried out that could possibly provide information about the combustion process?

    Finally, it is also possible that there is a problem with the injection nozzles/injectors. For example, a common point for the voltage supply.

    Also listen for noises (flow noises) in the engine compartment. There may be a leak on the affected bank.

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    Beste (luftgekühlte) Grüße

    Bernd

  • Go through everything that this cylinder bank has in common for all 3 cylinders.

    These are not the coils and plugs, it would be strange if they all went wrong together.

    And are you sure that the other bank has no misfires?

    Common to one bank are e.g:

    - Camshaft phaser

    - Lambda sensors (pre-cat sensor regulates the mixture)

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  • I have attached a picture of the error log. There are no other faults.

    We have carried out an emissions test. All values were normal.

    We will next check the engine for false air.

    If there is a problem with the camshaft phaser, shouldn't an error occur there? Is it possible that the Gutmann tester cannot read everything? The Durametric is often mentioned in the forum, can it penetrate further into the system?

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  • Find someone with piwis. Everything else is Tinneff/ Killefit/ ( who likes to add) Maybe here in the forum. Where are you from?

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  • I come from the Gunzenhausen / Ansbach area. ZIP CODE 91710 :wink:

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  • oh unfortunately I'm too much in the "north" but I'm sure someone will help you :wink:

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  • Lutzbert

    As Ray_S wrote, it's a good approach.


    I had very similar symptoms on my 997.2. It was the camshaft phaser. But you can easily check that. These are easily accessible (at least on the naturally aspirated engine) and can be replaced left/right. Then you can see whether the fault is also moving.


    Greetings

    Al

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  • I only know Gutmann for drinking.

    I'm happy to add PIWIS and Durametric, I'm from near Eichstätt.

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  • Lutzbert

    As Ray_S wrote, it's a good approach.


    I had very similar symptoms on my 997.2. It was the camshaft phaser. But you can easily check that. These are easily accessible (at least on the naturally aspirated engine) and can be replaced left/right. Then you can see whether the fault is also moving.


    Greetings

    Al

    To be more precise: You mean the solenoid valve of the camshaft phasing unit, not the phaser itself. This is located at the rear end of the camshaft and would be a real problem.

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