[Adholmes88]

Hi. A couple of weeks ago driving home my car bogged down on acceleration and came up with the drivetrain error

After nursing it home, I plugged it into my odb2 scanner and it came back with cylinder 6 misfire

I had the spark plugs and coil pack 6 changed on the car and all seemed fine.. until a few days ago driving home the same happened again!

Booked the car into bmw and they have the car now, on driving to the garage in limp mode (felt painfully sorry for the car) as it was struggling I plugged it into the odb2 scanner once I got there and it came up with misfire in cylinder 3 as well.

So far they’ve had the car all day and they seem to be struggling to find what’s wrong with the car as the machine they plugged it into didn’t come back with anything!

Apparently tomorrow they’ll clear all the codes on the car take it out for a run and see what’s what.

Any ideas would be most welcome and appreciated

[Pond]

How many miles on the car?

[Adholmes88]

Originally Posted by Pond

How many miles on the car?

34,000

I should add, I’ve had the car just over a year. I’ve only done 1,000 miles as I’m busy with work most of the time.

[Pond]

I'm no expert but it sounds like coil packs or plugs, but that is low mileage for either TBH.

What were the state of the plugs you had changed recently?

You said you had coil pack changed on the original offending cylinder misfire? And it hasn't shown up again on that cylinder?

[Adholmes88]

Originally Posted by Pond

I'm no expert but it sounds like coil packs or plugs, but that is low mileage for either TBH.

What were the state of the plugs you had changed recently?

You said you had coil pack changed on the original offending cylinder misfire? And it hasn't shown up again on that cylinder?

A few of the spark plugs did have a little oil on the tips and a little oil in the bottom of the spark plug tray.

Yeah changed coil pack 6 and the garage said nothing came up today on there machine which I’m surprised about

Thanks for the reply

[Pond]

It will be interesting to hear what the garage find (if anything), as the B58 engine, AFAIK has very few identified issues so far.

[Danj94]

if it were mine id be swapping the coil pack in cylinder 3 to another cylinder and see if the code follows it, that will tell you its a coil pack, if its still cylinder 3 then change plug (I know you said you did this) if its still struggling id get the vacuum system checked for leaks and pull the injector for cleaning/replacement.

[Eddamoo]

So the plug and coil change on 6 cleared the code initially and it came back? Are there currently multiple cylinder misfires or just one?

Multi cylinder misfires are far more likely to be something affecting the AFR or combustion process as a whole. Number one thing for me would be bad fuel but could also be an air leak or water/oil ingress.

[Adholmes88]

Originally Posted by Eddamoo

So the plug and coil change on 6 cleared the code initially and it came back? Are there currently multiple cylinder misfires or just one?

Multi cylinder misfires are far more likely to be something affecting the AFR or combustion process as a whole. Number one thing for me would be bad fuel but could also be an air leak or water/oil ingress.

Yes the codes were cleared and it came back. It was only a misfire on cylinder 6 but on my drive to the garage it appeared to misfire on cylinder 3 as well.

I did mention the fuel to them, I mentioned I didn’t drive much so only really fill up every 5-6 weeks. They said that should be fine but they sell an additive for cars that are sat for long periods of time

I always used shell v-power until about 3 months ago when I tried Esso 99 supreme, I’d like to think it’s not something to do with that but you never know

I’ll keep you updated with what the garage comes back with today

[Danj94]

Originally Posted by Adholmes88

Yes the codes were cleared and it came back. It was only a misfire on cylinder 6 but on my drive to the garage it appeared to misfire on cylinder 3 as well.

I did mention the fuel to them, I mentioned I didn’t drive much so only really fill up every 5-6 weeks. They said that should be fine but they sell an additive for cars that are sat for long periods of time

I always used shell v-power until about 3 months ago when I tried Esso 99 supreme, I’d like to think it’s not something to do with that but you never know

I’ll keep you updated with what the garage comes back with today

Was it defiantly fuel? I think oil leaks from the rocker cover gasket can pool in the spark plug wells?

[Alscoob]

Not quite related but had a similar issues on the wifes Z4 E89 with the N52 6pot engine. Cronic misfire so plugged the reader in and detected cylinder 6. So as the plugs hadn't been changed for a while decided to just buy a complete set and 2 coil packs just in case.

Swopped coil pack over first and was still there changed plug and still a misfire but this time on cylinder 4, seemed odd, so just swopped all plugs over for new and put the 2 new coil packs on 6 & 5 as they are the hardest to get to, started up cleared codes and all has been fine since, that was around 9 months ago.

Car is in regular use and does around 8k p.a and now has 86K on it.

340 plugs do need changing regularly, every second oil service so may be an issue with them and some short start stops? Maybe the plugs were not changed at the last service, seeing it's done 34k miles or are coming up for replacement? Be interesting to hear what dealer thinks but intermittent faults are the worst to find.

[Th3Walrus]

Originally Posted by Alscoob

340 plugs do need changing regularly, every second oil service

No they don't. First change is at 65,000-80,000km (40,000-50,000mi).

[Abzynthe]

Originally Posted by Th3Walrus

No they don't. First change is at 65,000-80,000km (40,000-50,000mi).

It’s in the service schedule as every other service. So every 4ish years. Mine were changed at 18k miles due to the mileage I do

[Alscoob]

Originally Posted by Abzynthe

It’s in the service schedule as every other service. So every 4ish years. Mine were changed at 18k miles due to the mileage I do

My car is having the plugs changed second time as part of the service as at 60K now as per service schedule mentioned above. May be different on other side of the pond?

[Th3Walrus]

Hmm.. must be different over here.

[Adholmes88]

That’s what they came back with at BMW. (Pic below)

It felt fine driving home but I’ve a feeling it will come back after a while.

I’ll keep you updated and fingers crossed 🤞

[Pond]

Originally Posted by Adholmes88

That’s what they came back with at BMW. (Pic below)

It felt fine driving home but I’ve a feeling it will come back after a while.

I’ll keep you updated and fingers crossed 🤞

Had a feeling they wouldn't find anything.

" 'puter says it's fine, so it must be!"

[Alscoob]

Originally Posted by Adholmes88

That’s what they came back with at BMW. (Pic below)

It felt fine driving home but I’ve a feeling it will come back after a while.

I’ll keep you updated and fingers crossed 🤞

I would probobly be keen to put a few more miles on it ASAP, apart from having an enjoyable drive and a laugh with the pops & bangs it'll prove them wrong or right. Better to go back to them quickly if if develops again rather than a few months down the line.

As long as you have BMW warranty / recovery

[Adholmes88]

So over one year on and the problem still lives with the car!


The misfire happened again last week with loads of white smoked coming from the exhaust on start up. The smoke clears away after 15-20 seconds.

It also happened around 6 months ago with the garage changing the coil pack and spark plugs again. (Took it to a bmw specialist this time) the compression on the cylinders were all coming back fine.

I’ve changed the pcv valve and noticed the old one did have a little hole in it.

Started up a few times since and only a very small amount of smoke comes out of the exhaust.

The three times it’s happened is just after I’ve brimmed the tank with fuel… can’t be a coincidence surely? Twice with Shell V-power and once with Esso supreme.

Any more ideas on this 🤞

[MaxB58]

Injector/s?

[TurboWeasel]

Sure it was smoke and not just condensation steam from standing so long?

Is it tuned?

Post #5 is slightly concerning regarding oil on the plug tips. There should never be oil anywhere on the plugs below the crush washer.

I think you might have a mechanical issue because new coils, plugs and sensors usually fix a related issue straight away.

[Adholmes88]

I’ve asked them to check the injectors tomorrow when it goes in the garage. It could be nice to get concrete evidence on what it is.

No the smoke isn’t just condensation, far too much smoke, I’ll try and attach a still picture of the smoke when it happened.

The car is tuned but it’s only BMW tuned no other modifications on the car.

Thanks for your reply’s