X1 with B48 engine

Ok this was interesting,,,car came in 2018 X1 with a B48 engine,,,check engine light was on misfire cylinder 1,,,checked and swapped spark plugs and ignition coils,,,no luck,,,,swap out fuel injector still misfire,,,car wouldn’t misfire fire at idle only misfired while driving,,,performed compression test good,,,checked ohm checked harness from DME to injectors and ignition coils,,,,harness and signals were good,,,,what the hell is going on with this piece of shit,,,lol,,,,,everything checked out ok.Well the next step was to remove the valve cover maybe a problem with the camshaft,,,what I found was camshaft bearing cap bolt was broken,,,,could not find the other half of the bolt,,,,you can see what it should look like,,,,so at idle the camshaft was sitting ok but when you revel the engine the camshaft was probably walking and would cause a misfire,,,,BMW want us to replace all the camshaft bearing cap bolts and test drive and hopefully everything will be ok.

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22 Responses to X1 with B48 engine

  1. mccrae2016 says:

    Where the hell did the other half of the bolt go?
    I would be worried that it might block something or jamb somewhere!


  2. Darren says:

    How to check ohm between dme and harness?


    • When you check the ohm reading I was just making sure the harness is good,,,,you will need a multimeter and set it to OHMS you will the have to find the same colored wire from the DME to the injector you want to check,,,you will attach the multimeter at the wire at the DME and the other multimeter lead at the injector and you will read if you have a good connection and no resistance or break in the harness,,,a good wire would be 0.0 Ohms to 0.06 Ohms


  3. Steve says:

    Great Catch!!!


  4. Ed says:

    Bolt broken? Wow… How could that happen? Must be a material defect


  5. JC says:

    ROFL..This isn’t the first time that a bolt on a BMW engine has backed itself out.


  6. JP says:

    Amazing, I would assume the other bearing supports would hold the camshaft down but apparently it can flex if it doesn’t have the proper support and that flex (fractions of milimiters) is enough to cause a misfire. Hollow camshaft?


  7. Kotletachka says:

    Quick question: 2012 528xi N20 Crank no start. No Spark. Fuel pressure at rails and exhaust smells like fuel when cranking. Checked all fuses, grounds, removed and charged battery separately (battery is from 2018), rear power module on battery all good, spark plugs are new, wiring is good from DME to coil (back probed ohms, all good.) Coils are good. Only one fault code 1130:27 Ignition relay and fuel injector voltage low. Engine malfunction in Red and Stability error screen in car. Only things I can think of is a faulty power control module found under the passenger side hood or DME failure. Your opinion would be greatly appreciated!


  8. Kotletachka says:

    Lubrication failure due to leaking plastic oil filter housing seized the motor. Engine has updated timing chains and guides and is timing using bmw timing tools.


    • Ok,,,,are you sure all the ground wires are hooked up and tight,,,if there are ok,,,you have to check the signal to the ignition coil,,,if I’m correct 1 wire is power,,,1 wire is ground,,,and the other wire is the the grounding signal from the DME to fire the ignition coil


      • Kotletachka says:

        Correct, I have checked all ground wires. When the car is powered on, one line sits at zeroV, other one jumps between 2.36-4.5v. When cranking the same thing. The module makes audible clicks while the car is on and when jumping. I only have access to newtis.info and will download ISTA later this evening to see if I can find better wiring schematics.


  9. kotletachka says:

    Dme’s are not supposed to make sloshing sounds and drip water when opened right?



    • No I don’t think so,,,,lol,,,,I guess you found you problem,,,,you can try and dry it out by putting it in a bag of white rice and the use a blow dryer and some electronic leaner and you might get lucky


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