When to change spark plugs

[JimD]

There are car parts that you almost know will fail in a specific interval so it makes sense to replace them first. Struts are probably not going to last much beyond 100K miles, for instance and probably influence handling negatively before that. Oil breaks down and must be changed. Despite what BMW says, I put engine coolant in the same category.

But I do not put coils, or most electrical components, into this category. They fail but the interval seems to vary widely. Some may last 200K miles or more while others fail during warranty. So I just run them to failure. It is far more controversial but I also treat the battery the same way. Mine is nearly 11 years old and is working fine. But I've had them go bad in less than 3 years in other cars. I do carry a jump starter, however.

[Gangplank]

Change the plugs based on recommended interval. Or at least check the gap on them. As they wear the gap gets bigger & the coils and other parts have to work harder resulting in added wear.

[bmw1racer]

Originally Posted by Gangplank

Change the plugs based on recommended interval. Or at least check the gap on them. As they wear the gap gets bigger & the coils and other parts have to work harder resulting in added wear.

What should the gap be for an N52 engine?

[Suprgnat]

Originally Posted by bmw1racer

What should the gap be for an N52 engine?

I see you searching around and all I see for Genuine is "the gap is preset at the factory". It is what it is.

FWIW 6 BNIB NGK LZFR6AP11GS 95712 measured .043, as per NGKs specs.
https://www.ngk.com/product.aspx?zpid=30699

[bmw1racer]

Originally Posted by Suprgnat

I see you searching around and all I see for Genuine is "the gap is preset at the factory". It is what it is.

FWIW 6 BNIB NGK LZFR6AP11GS 95712 measured .043, as per NGKs specs.
https://www.ngk.com/product.aspx?zpid=30699

OK... But why are some people specifying a gap nearly half that at 0.022"? A performance tweak of some kind?

[Suprgnat]

Originally Posted by bmw1racer

OK... But why are some people specifying a gap nearly half that at 0.022"? A performance tweak of some kind?

Why not toss out that corrupt data set and start fresh.

[WDE82]

Originally Posted by bmw1racer

OK... But why are some people specifying a gap nearly half that at 0.022"? A performance tweak of some kind?

Because that's the N54 gap and not the N52 gap. No one is tweaking spark plug gap for performance.

[bmw1racer]

Originally Posted by Suprgnat

Why not toss out that corrupt data set and start fresh.

Done.