N63 catalytic converter

image Ok here are your typical catalytic converter on a N63 or N63tu,,,,customer said check engine light came on,,,,we found rich mixture faults and bank 1 catalytic converter low efficiency ,,,,performed a catalytic converter test,,,but that didn’t help,,,so welcome to modern technology,,,,I took a bore scope and removed the down pipe and found the catalytic converter damaged.image So this job is not that bad,,,you have to remove the heat shields and vacuum pump to gain enough room to remove the catalytic converter,,,,if you are replacing bank 1 catalytic converter you don’t have to remove bank 2 catalytic converter,,,,,but if you need to replace bank 2 catalytic converter then you have to remove bank1 catalytic converter first to gain access,,,,so I got lucky just bank1 catalytic converter is coming out.image Here the whole catalytic converter removed with part of the down pipe,,,,which snakes behind the engine to the exhaust pipe.

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10 Responses to N63 catalytic converter

  1. Pawel says:

    I’ve heard something about the N63 turbo oil return lines getting clogged up with sludge and allegedly causing turbos to fail from running dry. Are there any symptoms to watch out for? Is there any way I can check if it’s happening to my engine using basic tools and an OBD scanner capable of logging parameters over time?


  2. Warren says:

    Thanks a lot for the great posting. It’s really helpful to understand and look over the general issues on the N63 engines. By the way, what kind of the damage occurred to the catalytic converter?
    I believe it’s also related to the heat issue. I can’t really tell from photos here so there would be enough space to squeeze this in there to protect plastic parts from the turbo heat?(https://www.amazon.com/DEI-010144-Titanium-Turbo-Shield/dp/B0039Z5TL8/ref=sr_1_1?rps=1&ie=UTF8&qid=1484163343&sr=8-1&keywords=dei+turbo+blanket&refinements=p_72%3A2661618011%2Cp_85%3A2470955011)


    • The damage to the catalytic converter was that it cracked,,,it was hard to show in the pictures,,,,but the honey comb cracked,,,,ok the problem wasn’t the heat,,,,the problem was the fuel injector were dumping fuel into the engine on bank1 ,,,,two weeks earlier,,,,,,so the car came back 2 weeks later with catalytic converter problem,,,,ok your turbo blanket,,,,there is no room under the heat shields for a blanket.


  3. Simon says:


    do you have had problems with leaky exhaust manifolds (itselve or gaskets) on N63 engines?
    Or is this not very common?

    Thank you very much!



  4. Chris says:

    Hello I have a bmw650xi coup 2013 I,had engine put in 8/2017, at 60,000, in 12/2020 I had another engine put in.In 1/2021 6 days later take care back when malfunction light , checked codes it sails left bank 1 lean then said 2. I live in ny and non BMW mechanics saism10 grand for the system is this possible.Also submitted paperwork in the class action suit on N63 engine


    • If you have lean faults after engine replacement it sounds like something the repair shop did when replacing the engine,,,question I don’t understand what “saism10 grand “ means


      • Christopher says:

        I apologize for that I was told the repair of the cats.would be about 10k he said that the heat from the engine cause the cats to melt a little causing the leans.I have put in two engines since 2017 both blew at about 60k. Thank you for taking the time


      • I would like to see what faults the repair shop got,,,if there are lean mixture faults there should also be some cat faults saying not efficient,,,they can also put a borescope inside the o2 sensor to check the cats,,,,just because it says lean faults doesn’t mean the cats are bad,,,,did they smoke test the intake system are the correct fuel injectors and are the calibrate to the engine swap


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