Misfire

[SwanJack]

We have a R56 mini ONE that's done 60k. Yesterday the car started misfiring badly and the CEL light came on in yellow. Drove it after an hour or so and the CEL went out. Took it to the local mini indie this morning and on the way there was a misfire on occasion under load, but the CEL stayed off. Garage read the key and nothing was showing. They booked it in for Monday to have a good look.

Anybody got any ideas? The car has always run on super unleaded, but the last tank my wife put in regular by mistake, although I doubt that this will have much effect (??)

Would an OBD scanner give up more fault codes than just reading the key (Eurocar parts have one for £20).

Thanks in advance

[and31]

Check the cheapest and most obvious first-coil pack,plugs,leads?

[Deep Thought]

SwanJack said:

We have a R56 mini ONE that's done 60k. Yesterday the car started misfiring badly and the CEL light came on in yellow. Drove it after an hour or so and the CEL went out. Took it to the local mini indie this morning and on the way there was a misfire on occasion under load, but the CEL stayed off. Garage read the key and nothing was showing. They booked it in for Monday to have a good look.

Anybody got any ideas? The car has always run on super unleaded, but the last tank my wife put in regular by mistake, although I doubt that this will have much effect (??)

Would an OBD scanner give up more fault codes than just reading the key (Eurocar parts have one for £20).

Thanks in advance

I would have thought so. Checking with a mate here in the trade who had one doing similar recently, will see what he says.

EDIT: he has come back via message and said it was the o2 sensor at the coil pack on his. He was able to get the code from a code reader and google it.

EDIT2: he also says it had burnt out 2 spark plugs because of that so he put new plugs in it too.

Edited by Deep Thought on Friday 25th January 20:58

[SwanJack]

So the misfire has been cured by way of new plugs and one new coil. The garage has picked up that the low pressure switch wire has been rubbing against the body and has broken through. They want £55 to fix it by way of re-solder. Seems a bit steep to me. Any thoughts?

[E-bmw]

DIY £0/mate with soldering iron £pint, done.

[SamR380]

Sounds like 1 hour's labour at a reasonable independent garage.

[SwanJack]

I thought about doing it myself until I saw where the break was. It's an hour at £47.50 plus the vat so their doing it (local Mini indie).