07-27-2018, 06:49 AM | #1 |
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Misfire and preventive maintenance repairs
Hi All,
Newbie here, with an Alpine White 2011 1M, with 23,500 kilometers (14,600 miles). No major mods, only midpipe delete and iDrive retrofit. Lately, i have been experiencing slight misfire during idle, and sometimes engine knock at 3,500 rpm. I always use 93-95 Octane fuel and have tried eliminating the cause of misfire and engine knock by using Redline Fuel System Cleaner twice (two full tank fill ups) which only cured the issue for a while. The car is mainly city driven and rarely driven hard for a long period of time (track driving). Maintenance intervals are done on time if not sooner. Diagnostics from the dealership showed no fault codes, however they did see slight misfire in cylinder 5 from the adaptation values. However, they did not advice on changing parts unless there is a fault. After reading through the list of common problems with 1M, i'm thinking of changing the knock sensor since it is a common issue as well as carbon cleaning as preventive maintenance and hopefully eliminating the misfire. Before i start changing unnecessary parts, maybe other members can chime in provide advice.. Appreciate the help guys, many thanks! |
07-28-2018, 10:33 AM | #2 |
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I have a similar slight miss at idle, especially when car sits for a a week or so. Mine doesn't knock or ping whatsoever but I had dealer look at mine. The did not find anything wrong at all and once you drive the car regularly it pretty much goes away. Their analysis tool says they have a smoothness parameter and two cylinders were slightly below the other four cylinders on the smoothness gauge but well within the spec. So all they told me that that I have the original coils which have been upgraded now and that I also have the original injectors which in the US have had the warranty extended and replaced with index 12. First, I assume by knock you mean pinging/detonation, not an actual knock like a rod knocks? If the car is truly pinging/detonation and the ECU is not doing anything about it, then it's probably ok to replace the knock sensor, but the knock sensor wouldn't cause the miss at idle. It just retards the timing if it detects detonation.
If you have the original coils, I would replace the coils and plugs first with the latest Delphi coils for 1M. The first version they revised them with were made by Eldor but apparently they didn't work as well as expected so currently, the BMW O.E. Delphi made coils are your best bet and use BMW OE spark plugs which are made by Bosch. It can't hurt to update the plugs and coild but I would consider injectors first and foremost. These are weakpoint in the 1M. If you have an injector that is underperforming, it could cause detonation. Direct injection is amazing because it allows you to run high compresession and boost that you couldn't do before. By putting the injector in the combustion chamber, the ECU can immediately adjust fuel charge to cool the cylinder and prevent detonation but if an injector is not working correctly, that cylinder will run hotter and could detonate. Bad coils and plugs can cause misfires and bad performance but not likely to cause detonation unless they are so carboned up that they become a glow plug. So if you just had a miss at idle I would change coils and plugs, especially if you have the outdated coils but if you actually have pinging/detonation, I would look at injectors next as the cause of the detonation. A lot of people will bring up carbon build up which could cause the rough idle but I don't think that will cause detonation. In old cars, carbon build up would happen in the cylinder which raises the compression of the cylinder but with direct injection, the carbon buildup happens in the intake manifold so you would get less air into the cylinder which would make more a richer fuel mixture which prevents detonation. On the other hand, if you have a substandard fuel injector that is not spraying enough fuel, that could the cylinder to lean out and detonate. The injectors could also cause a miss at idle. So my educated guess would be to look at injectors, then plugs and coils. Best wishes and let us know what you find out so we can all share information. |
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07-28-2018, 12:50 PM | #3 |
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coils and injectors. common issue. most people forget about them! these have happened to SO many people on the FB 1M owners group (which you should definitely join)
fuel injectors are covered by BMW as there is an upgraded part they installed for free. coils you're on your own!
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07-28-2018, 03:18 PM | #4 | |
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07-30-2018, 10:25 AM | #5 |
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You got OEM part numbers for the coils handy by any chance? Adding this to my list of maintenance parts to pick up when I get time. So Delphi makes the OEM coils? Would it be cheaper to just buy the Delphi branded coils as opposed to the BMW branded (made by Delphi) ones?
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07-30-2018, 12:45 PM | #6 | |
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07-30-2018, 01:04 PM | #7 |
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1st, change your spark plugs. They should be changed every 30K miles or third oil change. So maybe every three years. Changing the coil packs is't a bad idea... but IF you don't see the tach needle drop when you "feel" the miss fire... then it's probably a fuel or carbon buildup issue.
2nd, check for the injector upgrade campaign. Index 12's are the latest, I believe. 3rd, Carbon cleaning either walnut blasting of something like CRC's GDI cleaner spray. You will still need to R&R the intake manifold. 4th, Change your fuel brand. Some fuel brands act weird in some cars. Always use Premium fuel with as little(percentage) ethanol possible.
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10-22-2018, 12:26 PM | #8 |
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just had similiar issue on cyl 1 & 2, replace with new delphi coils, and now runs like a charm. First, I thought its the injectors but after my tech mess around the the coils and found out misfire move, so thats how you can tell if its coils. I already replace the sp plugs 10k miles ago, so check that out, will pay close attention for the next 2 years for the injectors before the warranty dies out.
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11-21-2018, 04:33 PM | #9 |
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I just ordered from FCPEuro some ignition set for $233 shipped, 100 installed. All new spark plugs and all new coils have not had a misfire since. Feels like it's running great again.
https://www.fcpeuro.com/ |
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11-22-2018, 03:08 AM | #10 |
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Hi all, I'm new here, just got an AW 2012 1M with only 8000 km on it.
Started to misfire the other day and idling really rough. Pulled the DME code and it was cylinder 6 misfire. Checked cyclinder 6 spark plug and it was fouled badly. I've then replaced all 6 plugs with OEM Bosch and all coils with Delphi. Car is running fine now. The injectors are still index 7 but from checking my MHD logs, they are still fine. I guess on these cars age does play part, not just mileage. Could have been a bad coil or a bad spark plug but I replaced them all. |
02-19-2019, 04:11 AM | #11 |
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The worst situation is if the camshafts are faulty...grooved camshaft bearing ledges causing VANOS codes.
When that happens the camshafts and a bunch of stuffs have to be replaced + labour to replace + labour to reset timing = $$$ Symptom would be misfire + Engine malfunction code + reduce power! Luckily I had that job completed by BMW through goodwill but that's not guaranteed after warranty is up. |
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