Rough idle -Spark Plugs?

[Stingraynut]

2014 VF Calais V Sportswagon 50,000kms regularly serviced.
Lately I've noticed a rough idle when stopped at the lights
The car has only done 50,000 kms.
I think it still runs rough as I accelerate from stop but hard to notice.
It's always been very thirsty around town and very low fuel use on long trips - that may just be how they are?

I'm wondering if I have a bad spark plug?
Maybe the iridium tip has fallen off one plug or something?
I found one video on changing VF plugs, but it doesn't show every step -

Is there a list of steps to change the plugs?

Are there any other reasons for the rough idle?

 

[gossie]

Plugs on your car normally get changed at around 100,000 kms.
Is that what you books say?
It’s not hard to change plugs or even pull one at a time to check them.

Is the air cleaner new?
Dirty air cleaner can affect things.
Very simple to buy and install a new one yourself.

 

[Sir Les]

It could be multitude of things -- plugs, coilpacks, injectors, airleak, even a faulty ecu (as happened to me on my VZ). You really need to get it checked by a mechanic or auto-electrician with a scan tool.
Oh, and my V6 VF uses around 12l / 100km in town and as little as 6.7l / 100km on a long run -- which I think is pretty good for a big, heavy car.

 

[HarryHoudini]

As above but also contaminated fuel.

 

[Sprog Dog]

2014 VF Calais V Sportswagon 50,000kms regularly serviced.
Lately I've noticed a rough idle when stopped at the lights
The car has only done 50,000 kms.
I think it still runs rough as I accelerate from stop but hard to notice.
It's always been very thirsty around town and very low fuel use on long trips - that may just be how they are?

I'm wondering if I have a bad spark plug?
Maybe the iridium tip has fallen off one plug or something?
I found one video on changing VF plugs, but it doesn't show every step -

Is there a list of steps to change the plugs?

Are there any other reasons for the rough idle?

My vehicle had a rough idle from new. Misfire in cylinder 1 finally detected at 30,000km. Ended up being a horizontal gouge in cylinder 1. Replacement engine needed. Check compression in cylinder and if down get a camera to look for gouging.

 

[shane_3800]

My vehicle had a rough idle from new. Misfire in cylinder 1 finally detected at 30,000km. Ended up being a horizontal gouge in cylinder 1. Replacement engine needed. Check compression in cylinder and if down get a camera to look for gouging.

That was likely from the ring catching on installation.

But the OPs issue is likely an injector from what I've seen on these engines.

 

[PeteSS]

Wouldn't a scan tool tell you where the issue is ?

Mine was hesitant under acceleration with a rougher than usual idle. scan said issue with cylinder 6. ended up being a fouled plug

 

[shane_3800]

Wouldn't a scan tool tell you where the issue is ?

Mine was hesitant under acceleration with a rougher than usual idle. scan said issue with cylinder 6. ended up being a fouled plug

No. The scan tool will just list cylinder miss fire X cylinder.

 

[Anthony121]

I just changed my plugs at 120k Kms on the SS and now it idles a bit smoother. The plugs didn't look too bad once out. Is your engine V6 or V8?

 

[lmoengnr]

I just changed my plugs at 120k Kms on the SS and now it idles a bit smoother. The plugs didn't look too bad once out. Is your engine V6 or V8?

Just done the same on my Redline, 112k kms. The original plugs looked almost perfect.