Intermittent misfire, very odd
Discussion
I have an intermittent misfire on my n54 335i, very strange, it done it about a month ago half way through a journey and next time I started the car up it was fine and been fine since, then done it twice today on 2 separate trips and both times it was ok after I started it up again. It seems to be when the engine is hot and starts at low revs. I'll put money on that it would be ok this week like before as generally my journeys are short.
Any one had a similar problem? I ordered a full set of coils as mine are 90k old, spark plugs are less than 10k old so they should be ok
Any one had a similar problem? I ordered a full set of coils as mine are 90k old, spark plugs are less than 10k old so they should be ok
You seem to be saying that the fault clears after a shut-down and restart. That sounds to me like the ECU resets itself. You definately need to get the codes read before you spend any money because the fault might have nothing to do with the plugs or coils, it could even be a faulty ECU.
Sebring440 said:
^^^^ This.
Why would you replace components without reading the codes to see what is actually causing the fault?
Because I haven't got a fault code reader and unless it's a bmw one I believe they just give generic codes which aren't that specific and I'm not driving 20 miles to.my nearest bm dealer then paying s million quid for the privilege. And regards of why cylinder it is, it's sensible to replace the lot isn't it as if the compo dents are all the same age, the rest are are sure to follow.
Why would you replace components without reading the codes to see what is actually causing the fault?
Because I haven't got a fault code reader and unless it's a bmw one I believe they just give generic codes which aren't that specific and I'm not driving 20 miles to.my nearest bm dealer then paying s million quid for the privilege. And regards of why cylinder it is, it's sensible to replace the lot isn't it as if the compo dents are all the same age, the rest are are sure to follow.
Andy70 said:
Because I haven't got a fault code reader and unless it's a bmw one I believe they just give generic codes which aren't that specific and I'm not driving 20 miles to.my nearest bm dealer then paying s million quid for the privilege. And regards of why cylinder it is, it's sensible to replace the lot isn't it as if the compo dents are all the same age, the rest are are sure to follow.
A generic code reader will VERY likely still tell you which cylinder it is, it doesn't need to be a BMW one. You could then swap a coil from a working cylinder. At the moment, you don't even know if it is a coil.With electronics just because one fails doesn't mean others are likely to follow.
Personally I would be finding out which one it is, if it is that & then you could get 2 to have a spare just in case, but certainly not changing all just in case it is one coil pack.
ratty6464 said:
Ignition coils. I’ve had exactly the same issues with a v8 M3 and a Mini Cooper s.
Advice would be to plug in Carly to detect which cylinder.
Also then change all 6 at the same time as more than one will likely fail in a short time
the issue has only occurred 3 times and not since the weekend, very odd and yes I will replace all 6 for what they cost, but do appreciate peoples comments Advice would be to plug in Carly to detect which cylinder.
Also then change all 6 at the same time as more than one will likely fail in a short time
gizlaroc said:
Also, when were the plugs replaced?
Many just presume coils, but often it is simply a plug needs replacing.
If doing coils I would pop a plug out and check them too, or just swap them all.
I did say in my original post, less than 10k I think, in fact I don't think I've done 10k in the car since I bought it, so actually probably 7000 miles oldMany just presume coils, but often it is simply a plug needs replacing.
If doing coils I would pop a plug out and check them too, or just swap them all.
If you own a BMW out of warranty it always worth getting yourself a code reader.
Either a Carly adapter or BM cables and old laptop, a computer science degree and time...you'll be able to diagnose and code stuff if no time.
I've been scarred by N53 engine misfires.....f
king pain in the arse those engines.
Either a Carly adapter or BM cables and old laptop, a computer science degree and time...you'll be able to diagnose and code stuff if no time.
I've been scarred by N53 engine misfires.....f
king pain in the arse those engines.E-bmw said:
A generic code reader will VERY likely still tell you which cylinder it is, it doesn't need to be a BMW one. You could then swap a coil from a working cylinder. At the moment, you don't even know if it is a coil.
With electronics just because one fails doesn't mean others are likely to follow.
Personally I would be finding out which one it is, if it is that & then you could get 2 to have a spare just in case, but certainly not changing all just in case it is one coil pack.
I get what you are saying about electronics, fair enough, but for the sake of 20 quid each, I may as well do the lot as its more hassle to get to them than the changing itself With electronics just because one fails doesn't mean others are likely to follow.
Personally I would be finding out which one it is, if it is that & then you could get 2 to have a spare just in case, but certainly not changing all just in case it is one coil pack.
Andy70 said:
I did say in my original post, less than 10k I think, in fact I don't think I've done 10k in the car since I bought it, so actually probably 7000 miles old
Cool, fair enough if you did them yourself. Just I have seen so many cars with plugs that 'were changed at the last service' that look like they have been in for 50k miles.
Had someone ask me to diagnose an issue the other week, was told needed new coil packs all round or injectors, same garage who told her that had done plugs 5k miles ago, they looked like the originals. £16 later all sorted.
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