Check Engine and severe judder at idle

[PJR]

Was driving home last night in my 2012 28i auto, and came to a set of lights where opportunity arose to set off briskly on green.

After flooring the pedal (in Sport Mode) the car moved off fine, but then something went a wry. The Check Engine light came on, with a warning that power was restricted and to drive modestly, and take it for service. At the next set of lights while in the queue the car had a really quite severe judder to it.

What’s the likely prognosis... is it plugs/coils (?) or something more grave?

[Smartbear]

Was driving home last night in my 2012 28i auto, and came to a set of lights where opportunity arose to set off briskly on green.

After flooring the pedal (in Sport Mode) the car moved off fine, but then something went a wry. The Check Engine light came on, with a warning that power was restricted and to drive modestly, and take it for service. At the next set of lights while in the queue the car had a really quite severe judder to it.

What’s the likely prognosis... is it plugs/coils (?) or something more grave?

You need fault codes to avoid throwing unnecessary parts at the car.
Rob

[B21]

It’s probably a plug/coil issue..when these happen the ECU disables that cylinder making the engine feel terrible plus warning lights etc..

Those faults reset themselves on next start up until it happens again.

As SmartBear says first port of call is a decent code reader..

[Starman]

I had this issue after putting the Dinan map on my car. I bought a Carly to analyze and it was spitting out a cylinder 6 problem. After advise from this site, I put in new plugs ($200) and haven't had a single issue since.

[wanderer]

Having similar issue. Has happened 3 times now.
After stopping emgine & restarting everything seems fine.
Carly throws up a Cylinder 4 problem.
Will start with spark plug replacements.

They should have been changed last October. But better me doing it myself for peace of mind.
Any idea what brand BMW uses or which do you guys suggest?

[Smartbear]

Having similar issue. Has happened 3 times now.
After stopping emgine & restarting everything seems fine.
Carly throws up a Cylinder 4 problem.
Will start with spark plug replacements.

They should have been changed last October. But better me doing it myself for peace of mind.
Any idea what brand BMW uses or which do you guys suggest?

Instead of changing relatively new plugs try swapping them around to see if the fault moves with the plug. That would prove it’s the plug.
Could save the cost of 6 plugs
Rob

[B21]

Having similar issue. Has happened 3 times now.
After stopping emgine & restarting everything seems fine.
Carly throws up a Cylinder 4 problem.
Will start with spark plug replacements.

They should have been changed last October. But better me doing it myself for peace of mind.
Any idea what brand BMW uses or which do you guys suggest?

Instead of changing relatively new plugs try swapping them around to see if the fault moves with the plug. That would prove it’s the plug.
Could save the cost of 6 plugs
Rob

Boy speaks a lot of sense..FWIW I bet its a coil!

[wanderer]

Having similar issue. Has happened 3 times now.
After stopping emgine & restarting everything seems fine.
Carly throws up a Cylinder 4 problem.
Will start with spark plug replacements.

They should have been changed last October. But better me doing it myself for peace of mind.
Any idea what brand BMW uses or which do you guys suggest?

Instead of changing relatively new plugs try swapping them around to see if the fault moves with the plug. That would prove it’s the plug.
Could save the cost of 6 plugs
Rob

True.
If that last service report is to be believed the plugs should be fine.

I will start by swapping the coil first and see if the problem manifests itself on the swapped cylinder then go from there.
The plugs aren't an expense, relatively. But boy are those ignition coils expensive. Didn't know they are a common failure point until i asked and googled.

thanks

[B21]

Having similar issue. Has happened 3 times now.
After stopping emgine & restarting everything seems fine.
Carly throws up a Cylinder 4 problem.
Will start with spark plug replacements.

They should have been changed last October. But better me doing it myself for peace of mind.
Any idea what brand BMW uses or which do you guys suggest?

Instead of changing relatively new plugs try swapping them around to see if the fault moves with the plug. That would prove it’s the plug.
Could save the cost of 6 plugs
Rob

True.
If that last service report is to be believed the plugs should be fine.

I will start by swapping the coil first and see if the problem manifests itself on the swapped cylinder then go from there.
The plugs aren't an expense, relatively. But boy are those ignition coils expensive. Didn't know they are a common failure point until i asked and googled.

thanks

Last time I looked NGK coils were just over £20

[PJR]

Thanks for all the info folks- super helpful as always on here!

So two further questions...

Will a £25 code reader from amazon do the trick or is there a smarter option to buy, eg is a Carly worth seeking out?

If it is a plug or a coil, are these serviceable by a complete and utter mechanical clutz (ie me) or better take to a garage?

[wanderer]

Thanks for all the info folks- super helpful as always on here!

So two further questions...

Will a £25 code reader from amazon do the trick or is there a smarter option to buy, eg is a Carly worth seeking out?

If it is a plug or a coil, are these serviceable by a complete and utter mechanical clutz (ie me) or better take to a garage?

Plugs & coils are entirely doable on your own.
The coil just requires pulling up on a plastic cap, pulling out the wiring and then tugging on the coil to remove.
You will have to remove plastic engine cover first.

The plugs can be easy or difficult depending on if they are stuck and won't turn. In that case it's worth spraying some penetrant spray and waiting an hour or so. You certainly don't want to break the plug.

Here's an explainer video:
https://youtu.be/-Vyap3DkW-E

On the code reader - it depends.
I have a Creador C110 which I got initially for my 3 Series. It's about £48 on Amazon.

Since then I got the Carly. It not only does diagnostics but also allows you to code certain features.
The one downside is that it is based on an annual subscription.

Out of interest, when you experienced the problem, were you low on fuel? I.e had the fuel warning message come on?

[PJR]

Thanks Wanderer, that’s great.

No, the fuel light wasn’t on as far as I recall.

I have taken a punt on a cheap reader so I could get it delivered today, so I’ll see how I get on, thought it was worth a punt for the money.

If it is the plugs, is it better to change them all at once or just change the faulty one (s),,?

[B21]

Thanks Wanderer, that’s great.

No, the fuel light wasn’t on as far as I recall.

I have taken a punt on a cheap reader so I could get it delivered today, so I’ll see how I get on, thought it was worth a punt for the money.

If it is the plugs, is it better to change them all at once or just change the faulty one (s),,?

If one plug has gone then the others will not be far behind..ditto on coils..

[PJR]

Thanks, that makes sense.

[wanderer]

Thanks Wanderer, that’s great.

No, the fuel light wasn’t on as far as I recall.

I have taken a punt on a cheap reader so I could get it delivered today, so I’ll see how I get on, thought it was worth a punt for the money.

If it is the plugs, is it better to change them all at once or just change the faulty one (s),,?

Did you get the codes read?