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      10-20-2021, 05:21 PM   #1
stresseric
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B48 320i misfire after new spark plugs

Okay so I'll try and keep this short and sweet. A few weeks back I took my f30 in for it's annual service at my "Main dealer alternative" garage, nothing crazy just fresh sparkplugs, oil and filters. When collecting my car, I noticed it had a rough idle, definitely wasn't there when I dropped it off. The next morning I set off for work and didn't even make it off my drive before I got hit with a drive chain error. The car starts to vibrate like crazy and sounds like its running on 3 cylinders...

Back to the garage it goes, probably just a bad sparkplug they reassure me. New plugs all round and off I go. Half a mile down the road and the drive chain error is back. This time I leave it with them, after running diagnostics they determine that the car is misfiring on cylinder 2. The garage then swaps coil packs and injectors around. the misfire remains in cylinder 2. Then, compression checks followed by a camera in the cylinder, no obvious damage.

At this point the garage refused to continue diagnosing my car unless I had my car unmapped (probably should have mentioned the map earlier, stage 1 tune, 260bhp installed professionally on a dyno well over 6 months ago. Basically the same power as the 330i) according to the garage its more than likely the map however, a mechanic friend told me the opposite plus I cant seem to find any examples online of remaps causing misfires after new plugs. Honestly I'm starting to loose faith in the garage completely.

Nevertheless. I collected my car from the garage today and dropped it off with the tuner for them to look at, figured its worth a shot but I'd be very surprised if that was all that's wrong. I should hear back in the next day or so.

Any advice of suggestions would be hugely appreciated as I'm starting to loose my mind!
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      10-21-2021, 08:36 AM   #2
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Quote:
Originally Posted by stresseric View Post
Okay so I'll try and keep this short and sweet. A few weeks back I took my f30 in for it's annual service at my "Main dealer alternative" garage, nothing crazy just fresh sparkplugs, oil and filters. When collecting my car, I noticed it had a rough idle, definitely wasn't there when I dropped it off. The next morning I set off for work and didn't even make it off my drive before I got hit with a drive chain error. The car starts to vibrate like crazy and sounds like its running on 3 cylinders...

Back to the garage it goes, probably just a bad sparkplug they reassure me. New plugs all round and off I go. Half a mile down the road and the drive chain error is back. This time I leave it with them, after running diagnostics they determine that the car is misfiring on cylinder 2. The garage then swaps coil packs and injectors around. the misfire remains in cylinder 2. Then, compression checks followed by a camera in the cylinder, no obvious damage.

At this point the garage refused to continue diagnosing my car unless I had my car unmapped (probably should have mentioned the map earlier, stage 1 tune, 260bhp installed professionally on a dyno well over 6 months ago. Basically the same power as the 330i) according to the garage its more than likely the map however, a mechanic friend told me the opposite plus I cant seem to find any examples online of remaps causing misfires after new plugs. Honestly I'm starting to loose faith in the garage completely.

Nevertheless. I collected my car from the garage today and dropped it off with the tuner for them to look at, figured its worth a shot but I'd be very surprised if that was all that's wrong. I should hear back in the next day or so.

Any advice of suggestions would be hugely appreciated as I'm starting to loose my mind!
Was there any codes thrown? Could be an injector problem on #2 but they don't just go bad suddenly after a plug change. Screw-up cover-up?
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      10-21-2021, 06:32 PM   #3
stresseric
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Originally Posted by BMWILUVU View Post
Was there any codes thrown? Could be an injector problem on #2 but they don't just go bad suddenly after a plug change. Screw-up cover-up?
Code was thrown, didn't see it myself but I'm told it indicated a misfire in cylinder 2. Had a call back from the tuner garage this afternoon, apparently the new plugs already have carbon build up indicating over fuelling. They recommended that I get a full set of new injectors. Seems excessive but I can appreciate if one has failed the others can't be far behind. I had suspected injectors from the start but the first garage claimed to have swapped the injector off cylinder 2 with another, yet the misfire remained...

Correct me if I'm wrong but surely you can't just swap injectors around without coding. now I'm left wondering who to trust. I don't mind dropping the cash on new injectors as long as I'm not then told its something else.
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      10-22-2021, 05:39 AM   #4
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Quote:
Originally Posted by stresseric View Post
Okay so I'll try and keep this short and sweet. A few weeks back I took my f30 in for it's annual service at my "Main dealer alternative" garage, nothing crazy just fresh sparkplugs, oil and filters. When collecting my car, I noticed it had a rough idle, definitely wasn't there when I dropped it off. The next morning I set off for work and didn't even make it off my drive before I got hit with a drive chain error. The car starts to vibrate like crazy and sounds like its running on 3 cylinders...

Back to the garage it goes, probably just a bad sparkplug they reassure me. New plugs all round and off I go. Half a mile down the road and the drive chain error is back. This time I leave it with them, after running diagnostics they determine that the car is misfiring on cylinder 2. The garage then swaps coil packs and injectors around. the misfire remains in cylinder 2. Then, compression checks followed by a camera in the cylinder, no obvious damage.

At this point the garage refused to continue diagnosing my car unless I had my car unmapped (probably should have mentioned the map earlier, stage 1 tune, 260bhp installed professionally on a dyno well over 6 months ago. Basically the same power as the 330i) according to the garage its more than likely the map however, a mechanic friend told me the opposite plus I cant seem to find any examples online of remaps causing misfires after new plugs. Honestly I'm starting to loose faith in the garage completely.

Nevertheless. I collected my car from the garage today and dropped it off with the tuner for them to look at, figured its worth a shot but I'd be very surprised if that was all that's wrong. I should hear k in the next day or so.

Any advice of suggestions would be hugely appreciated as I'm starting to loose my mind!
If you did a compression test, what were the results for all four cylinders?
If they changed plugs and problem occurred, it should be something related to what they did. It can be lose connection, bad plugs, ect.

For the misfire, it can be plugs, coils, injectors, bad fuel, or even damaged pistons.

To troubleshoot this, I will recommend pulling the plugs and inspecting. Then get a compression test to ensure engine healthy. If you are getting misfire on cylinder 2 try swapping plug and coils to the other cylinders and see if the fault moves. If it don't then you can lift fuel rail and test injectors. Then swap injectors and see if the fault moves. Have these done by someone good, report back with results if you need further assistance.

Compression Test Video:


Injector Test Video @7:18:
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      10-22-2021, 06:03 AM   #5
stresseric
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Quote:
Originally Posted by SRHosein View Post
Quote:
Originally Posted by stresseric View Post
Okay so I'll try and keep this short and sweet. A few weeks back I took my f30 in for it's annual service at my "Main dealer alternative" garage, nothing crazy just fresh sparkplugs, oil and filters. When collecting my car, I noticed it had a rough idle, definitely wasn't there when I dropped it off. The next morning I set off for work and didn't even make it off my drive before I got hit with a drive chain error. The car starts to vibrate like crazy and sounds like its running on 3 cylinders...

Back to the garage it goes, probably just a bad sparkplug they reassure me. New plugs all round and off I go. Half a mile down the road and the drive chain error is back. This time I leave it with them, after running diagnostics they determine that the car is misfiring on cylinder 2. The garage then swaps coil packs and injectors around. the misfire remains in cylinder 2. Then, compression checks followed by a camera in the cylinder, no obvious damage.

At this point the garage refused to continue diagnosing my car unless I had my car unmapped (probably should have mentioned the map earlier, stage 1 tune, 260bhp installed professionally on a dyno well over 6 months ago. Basically the same power as the 330i) according to the garage its more than likely the map however, a mechanic friend told me the opposite plus I cant seem to find any examples online of remaps causing misfires after new plugs. Honestly I'm starting to loose faith in the garage completely.

Nevertheless. I collected my car from the garage today and dropped it off with the tuner for them to look at, figured its worth a shot but I'd be very surprised if that was all that's wrong. I should hear k in the next day or so.

Any advice of suggestions would be hugely appreciated as I'm starting to loose my mind!
If you did a compression test, what were the results for all four cylinders?
If they changed plugs and problem occurred, it should be something related to what they did. It can be lose connection, bad plugs, ect.

For the misfire, it can be plugs, coils, injectors, bad fuel, or even damaged pistons.

To troubleshoot this, I will recommend pulling the plugs and inspecting. Then get a compression test to ensure engine healthy. If you are getting misfire on cylinder 2 try swapping plug and coils to the other cylinders and see if the fault moves. If it don't then you can lift fuel rail and test injectors. Then swap injectors and see if the fault moves. Have these done by someone good, report back with results if you need further assistance.
Quote:
Originally Posted by SRHosein View Post
Quote:
Originally Posted by stresseric View Post
Okay so I'll try and keep this short and sweet. A few weeks back I took my f30 in for it's annual service at my "Main dealer alternative" garage, nothing crazy just fresh sparkplugs, oil and filters. When collecting my car, I noticed it had a rough idle, definitely wasn't there when I dropped it off. The next morning I set off for work and didn't even make it off my drive before I got hit with a drive chain error. The car starts to vibrate like crazy and sounds like its running on 3 cylinders...

Back to the garage it goes, probably just a bad sparkplug they reassure me. New plugs all round and off I go. Half a mile down the road and the drive chain error is back. This time I leave it with them, after running diagnostics they determine that the car is misfiring on cylinder 2. The garage then swaps coil packs and injectors around. the misfire remains in cylinder 2. Then, compression checks followed by a camera in the cylinder, no obvious damage.

At this point the garage refused to continue diagnosing my car unless I had my car unmapped (probably should have mentioned the map earlier, stage 1 tune, 260bhp installed professionally on a dyno well over 6 months ago. Basically the same power as the 330i) according to the garage its more than likely the map however, a mechanic friend told me the opposite plus I cant seem to find any examples online of remaps causing misfires after new plugs. Honestly I'm starting to loose faith in the garage completely.

Nevertheless. I collected my car from the garage today and dropped it off with the tuner for them to look at, figured its worth a shot but I'd be very surprised if that was all that's wrong. I should hear k in the next day or so.

Any advice of suggestions would be hugely appreciated as I'm starting to loose my mind!
If you did a compression test, what were the results for all four cylinders?
If they changed plugs and problem occurred, it should be something related to what they did. It can be lose connection, bad plugs, ect.

For the misfire, it can be plugs, coils, injectors, bad fuel, or even damaged pistons.

To troubleshoot this, I will recommend pulling the plugs and inspecting. Then get a compression test to ensure engine healthy. If you are getting misfire on cylinder 2 try swapping plug and coils to the other cylinders and see if the fault moves. If it don't then you can lift fuel rail and test injectors. Then swap injectors and see if the fault moves. Have these done by someone good, report back with results if you need further assistance.
Already had a compression test, they didn't give me the results but said all cylinders were fine. Had the plugs swapped out multiple times since the misfire started. The garage it's with currently said when they pulled the new plugs they already had black carbon buildup on the tips. They also swapped the coil packs around but the misfire stayed with cyl 2. The last garage also swapped the injectors around but cyl 2 still had the misfire. Could it be possible that all my injectors are on the way out and cyl 2 is just the first one to hit a misfire. Cheers for taking the time to respond btw
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      10-22-2021, 10:17 AM   #6
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Quote:
Originally Posted by stresseric View Post
Code was thrown, didn't see it myself but I'm told it indicated a misfire in cylinder 2. Had a call back from the tuner garage this afternoon, apparently the new plugs already have carbon build up indicating over fuelling. They recommended that I get a full set of new injectors. Seems excessive but I can appreciate if one has failed the others can't be far behind. I had suspected injectors from the start but the first garage claimed to have swapped the injector off cylinder 2 with another, yet the misfire remained...

Correct me if I'm wrong but surely you can't just swap injectors around without coding. now I'm left wondering who to trust. I don't mind dropping the cash on new injectors as long as I'm not then told its something else.
On my f-series 6-pot engine, the injector install only required reset of adaptations. If you installed it yourself and knew what you were doing, you could just replace one injector and replace others when they are on their way out but if you know know your way around, it'd be better to replace them all at once. Perhaps you can talk them into a better deal on the injectors if you sourced them yourself or get Bosch aftermarket versions of the same injector made by Bosch.
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      10-24-2021, 08:08 PM   #7
SRHosein
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Quote:
Originally Posted by stresseric View Post
Already had a compression test, they didn't give me the results but said all cylinders were fine. Had the plugs swapped out multiple times since the misfire started. The garage it's with currently said when they pulled the new plugs they already had black carbon buildup on the tips. They also swapped the coil packs around but the misfire stayed with cyl 2. The last garage also swapped the injectors around but cyl 2 still had the misfire. Could it be possible that all my injectors are on the way out and cyl 2 is just the first one to hit a misfire. Cheers for taking the time to respond btw
To advise better, I would need the results of the compression test, B48 pistons are weak lol. If they swapped, coils, plugs, and injectors and same issue on cylinder 2 then there is most likely a problem with the cylinder (possibly piston 2 ringland cracked). It can also be damaged wiring, ECU, injector/coils not jacked in properly ect. I would say have it checked out by someone good as it may result in spending unnecessary money. All the best troubleshooting
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      11-08-2021, 01:21 PM   #8
stresseric
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Quote:
Originally Posted by SRHosein View Post
To advise better, I would need the results of the compression test, B48 pistons are weak lol. If they swapped, coils, plugs, and injectors and same issue on cylinder 2 then there is most likely a problem with the cylinder (possibly piston 2 ringland cracked). It can also be damaged wiring, ECU, injector/coils not jacked in properly ect. I would say have it checked out by someone good as it may result in spending unnecessary money. All the best troubleshooting
bingo! unfortunately it appears you were right, gave the go ahead to have the motor pulled last week and as you said piston 2 was cracked. looks like the total bill with labour will over 2500. Now I have a bit of a dilemma on my hands, as I mentioned the car went for its service at the garage in full working order then on return had the rough idle immediately then followed by the misfire. Not sure where I would stand in regards to laying the blame on the garage that conducted the service. could it be possible the plugs were over tightened, resulting in a cracked piston head? or something along those lines. I can't get my head around it. Surely it isn't just a coincidence.
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