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.
-
Recent Comments
vic san on N20 vanos unit broken Mark on N55 intake camshaft beari… JC on F30 A/C noise Jordan on New B engine mechanical water… jmiddle204 on X3 4×4 transfer case
bmwtechnician 
Where the hell did the other half of the bolt go?
I would be worried that it might block something or jamb somewhere!
LikeLike
We believe it dropped down into the oil pan,,,there is a big oil drain hole next to the camshaft bearing cap
LikeLike
Hi question have a 2002 BMW e39 525i around 140k miles, cyinder 6 misfire at idle or low rpm swapped coils/spark plug no change, compression is 90 psi on cyl 6 rest is 140 any advice
Thanks
LikeLike
What problems are we having,,,are we having rough running or misfires?,,,,90psi is a problem,,,several things could cause this,,,maybe slight head gasket leak at back of cylinder head near cylinder 6,,,maybe bad or leaking exhaust or intake valve,,,or piston rings bad,,,or could remove the spark plug and put some oil inside the cylinder and see if the compression comes backup.,,,you could also perform a leakage test to see what is leaking in the cylinder
LikeLike
Cylinder 6 misfire with fuel cut off at idle after reset it comes back to normal, but will not happen if you drive the car above 40 or 50mph only if left idle for 2-4 mins or low rpm
LikeLike
Are you sure the fuel injector is ok,,,,did you check the spark plugs for fuel soak
LikeLike
Lets say we put some oil in cylinder 6 and it comes back up what could be the issue piston rings ?
LikeLike
Yes if you put oil in and it comes back up,,,,,it’s probably piston rings
LikeLike
How to check ohm between dme and harness?
LikeLike
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
LikeLike
Great Catch!!!
LikeLike
Bolt broken? Wow… How could that happen? Must be a material defect
LikeLike
We don’t know and BMW doesn’t know,,,it could be a material defect maybe bolts not heat treated,,,or maybe it wasn’t torque down properly.
LikeLike
How can the torque be wrong? Was it assembled by robots?
LikeLike
Its possible that the proper torque was not set,,,because we noticed some of the other bearing caps were on the loose side,,,I don’t know if it was assembled by robots,,,robots can also make mistakes I guess
LikeLike
@Concerned
Even robots need re-calibration. It has happened before.
LikeLike
ROFL..This isn’t the first time that a bolt on a BMW engine has backed itself out.
LikeLike
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?
LikeLike
Yes hollow camshaft
LikeLike
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!
LikeLike
Also, the car started on two cylinders for about 5 seconds after the engine swap and never restarted.
LikeLike
So this is a engine swap,,,why did we do a engine swap?
LikeLike
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.
LikeLike
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
LikeLike
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.
LikeLike
Ok
LikeLike
Dme’s are not supposed to make sloshing sounds and drip water when opened right?
😦
LikeLike
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
LikeLike
Good day everybody ,
we try to start but seens like no firing , if we connect outer plug on earth we see it like random misfire.
we reassembly new heads on F10 b44 and there is problem with starting , faults from diagnosis is CD8E10 .
Faults in Ista are on booth DME (brown color) and sometimes it seens like fauts are changing
Is possible to simulate some test or measuring points on Flexray bus if they are ok ?
Dont You know how to resolve this problem?
Thanks for all advices in advance
Bye
Paul
LikeLike
Question was engine running before you replaced the head,,,and why did you replace the cylinder head,,,are you sure the engine is timed correctly.
You said the fault keeps changing DME (brown color) I don’t understand.
No there is no test to simulate flex ray bus signal .
Make sure all you plugs and connector are all plugged in
LikeLike
Thank you for reply 😉
Yes , motor was running , only there was leaking thru headgaskets , it was preventive repair , we buy new Bmw heads , gaskets , factory assembled with camshafts and plumbed vario cam , …and other required original parts we buy
..assembly the motor and proceed timing with original bmw set, going thru manual.
Diagnosis check display faults on LIM bus in DME (sometimes only DME1 sometimes on booth) , firing seens sometimes wrong , but is present on plugs with very yellow flashes
The engine sounds like without compressions . You can hear first two compresions but then very soft noise without pressure
Isn’t here possible to turn cams about 180°
Or maybe some mistake on Bus , because still write that is no communication
Thanks for all your topics
Nice day 😉 Paul
LikeLike
I have a question what motor do you have,,,because you said B44 which that doesn’t exist and you said DME 1,,,so do you have a N63tu V8 twin turbo,,,and yes you could have the camshaft 180 out which is easy to do.,,,you also said no communication to what,,,,no communications to a DME?
LikeLike