something feels off with the engine (erratic idling)

[darrko]

Hi guys, my car is now at 27K+ miles (MY2015) so not really a huge annual run. Lately I feel like the engine is slightly erratic while idling. Its a very subtle feeling which no one else might notice but when you drive your car every day you can sense when something is different. It is hard to describe exactly what it is but it feels out of sync, which leads me to believe it might be a timing belt issue. Is there a sure way to tell if its the timing belt? I don't want to take it in to a garage without having some relevant knowledge from top gents such as yourself.

Please advise on how I can get closer to the possible cause for the subtle erratic idling. Thanks!

[ricardofors68]

When was the last time you drove the car? I dont think your timing chain is the problem. I would start looking at regular maintenance components. Slight hesitation can be caused by a number of things. I would start by determining when you changed plugs, filters, gas, type of gas, filters, etc. All of these might throw a code or might not. I assume you do not have a cel on? Rule out nothing. I would even suspect a weak battery.
Unfortunately, low miles might not be a good indicator of condition.

[darrko]

I drive it everyday. The car goes for regular service checks & maintenance as per BMW notifications plus annual MOT here in the UK. The most recent work was carried out when my engine coolant started leaking and I had to take it in for replacement of a part that had cracked. This was at an independent garage as the next available slot at a BMW service center was few months later.

I will most likely take it in to the same garage as I found their work satisfactory, just wanted to be aware of the possible causes. So could be spark plugs? What’s cel, sorry I don’t understand.

[m5rosco]

It could literally be one of a hundred things. First things first, these cars do not have timing belts. and CEL = Check Engine Light.

When were the spark plugs last changed? It could also be a faulty coil pack, air flow meter, injector, the list goes on. Also what petrol do you use?

[darrko]

Originally Posted by m5rosco

It could literally be one of a hundred things. First things first, these cars do not have timing belts. and CEL = Check Engine Light.

Check engine light is not on. Do they have something similar to a timing belt? A timing chain, I read somewhere. Could it be that?

When were the spark plugs last changed? It could also be a faulty coil pack, air flow meter, injector, the list goes on. Also what petrol do you use?

Not sure about spark plugs last change, I will check. Petrol I exclusively use high octane.

Is it better to take it to BMW service center or would it be fine to just get it checked at a reputable garage? With BMW I will most likely be waiting weeks, if not months, for an appointment slot.

Thanks for the response.

[M5Rick]

It's unlikely to be timing chain, and again there is no timing belt.
I use a BMW agent outside the Gt.London area for better service and quicker booking in, do you have a BMW service book where services are recorded and stamped by the agent..there is a section in there for spark plug change and when done.

[darrko]

Originally Posted by M5Rick

I use a BMW agent outside the Gt.London area for better service and quicker booking in, do you have a BMW service book where services are recorded and stamped by the agent..there is a section in there for spark plug change and when done.

can you please share details of this BMW agent outside London? I am a bit apprehensive about taking it to a non-BMW mechanic. Should I be worried or is the spark plug change just as straightforward process for these M cars as regular cars?

[M5Rick]

Originally Posted by darrko

can you please share details of this BMW agent outside London? I am a bit apprehensive about taking it to a non-BMW mechanic. Should I be worried or is the spark plug change just as straightforward process for these M cars as regular cars?

I take mine to BMW Redhill for service, MOT and oil change at same time and they did my plugs last year.
It's not a straight forward job which involves other parts to be removed for access, some of which are fiddly and tricky to remove so I would advize for them to do it for peace of mind with the 2 year parts and labour guarantee you get with that. Book it for 'while you wait' service and remember engine has to cool for them to be able to work on it.

[m5rosco]

Originally Posted by darrko

can you please share details of this BMW agent outside London? I am a bit apprehensive about taking it to a non-BMW mechanic. Should I be worried or is the spark plug change just as straightforward process for these M cars as regular cars?

Whereabouts actually are you? What garage did you use previously?

Plugs are a very straightforward job.

I'm not from London, but these few always get really good reviews in various groups I'm in, and highly regarded by people whose opinions I trust, and I wouldn't hesitate to use any of them if they were closer....

www.munichpower.co.uk Surrey RH1 5JJ
www.gndmotors.co.uk Thurrock RM20 3EE
www.ultimatevelocity.co.uk Aldershot GU12 5QF
www.bmminitech.co.uk Colchester CO7 6HR

I'm sure there's many more too.

Hope that helps.

[C-dub]

The first thing I'd do is remove and clean your MAF sensors. It's a 30 minute job and takes zero skill. Just look online for the tutorials. I did it and it smoothed out my rough idle. If that doesn't work, next step would probably be o2 sensors or plugs depending on how long it's been since your last plug change.

[darrko]

Originally Posted by m5rosco

Whereabouts actually are you? What garage did you use previously?

Plugs are a very straightforward job.

I'm not from London, but these few always get really good reviews in various groups I'm in, and highly regarded by people whose opinions I trust, and I wouldn't hesitate to use any of them if they were closer....

www.munichpower.co.uk Surrey RH1 5JJ
www.gndmotors.co.uk Thurrock RM20 3EE
www.ultimatevelocity.co.uk Aldershot GU12 5QF
www.bmminitech.co.uk Colchester CO7 6HR

I'm sure there's many more too.

Hope that helps.

Thanks for all the helpful advice. I’m in West London so Munich Power looks like a good option. Still an hour drive away but that’s to be expected. I usually take in my car for regular service to Berry’s Chiswick BMW or Park Royal but they are usually booked up months ahead.

[darrko]

Originally Posted by C-dub

The first thing I'd do is remove and clean your MAF sensors. It's a 30 minute job and takes zero skill. Just look online for the tutorials. I did it and it smoothed out my rough idle. If that doesn't work, next step would probably be o2 sensors or plugs depending on how long it's been since your last plug change.

I’ve never worked on my car before but I’ll give it a shot 👍🏼

[vafan13]

Originally Posted by darrko

I’ve never worked on my car before but I’ll give it a shot ����

Its very easy. Just make sure you use a cleaner which is safe for MAF sensors. Something like CRC Mass Airflow Sensor Cleaner. It should dry quickly, but to be extra safe I'd let it sit over night.