[GoVikings]

Hi,

my X3 2017 35i only has about 32000km (20k miles). I was told by the dealership that in 2023 I will need spark plugs changed per BMW service guidelines, regardless of the mileage, which might only be about 27k miles at that point. That is the 6th year of the vehicle. However, another reliable independent mechanic told me that they usually don't need to be changed until 60k miles.

Thoughts? I am looking at getting the prepaid service package, which seems like a good deal to me ($700USD for 3 years extra routine service, which will include 3x oil change, 1x air con filter change, 1x spark plugs change, 1x radiator flush I believe). However, if spark plugs really don't need to be changed, then it changes the math completely.

[Wgosma]

Your Independent mechanic is correct; you should be able to get 50K+ miles out of a set of plugs on your N55 motor w/Turbo. Plug change interval is a mileage (not age) based thing.

I'm guessing a bit here, but I bet a Dealer would charge $500+ just to install new plugs as a stand alone job.

[najnad]

There isn't much agreement online as to how long spark plugs last. Anywhere from 20k to 80k miles. Turbocharged, supercharged, and modified engines usually fall on the lower end of the spectrum. But the real factor you should be looking for is how is the engine running? Hesitation, rough idle, less acceleration, less gas mileage, longer crank to start, etc all could be signs your spark plugs need to be replaced.

BMW guidelines likely assume you drive at least 10k miles a year, so makes sense they would call for spark plug replacement by year 6. Personally, I would do it sooner than 60k miles, but I also don't wait 15k miles for oil changes and I changed the lifetime fluid in my transmission.

[spelk3]

What is the correct spark plug gap for a N55 X3?

[KC87ZB]

Direct Injection engines are harder on spark plugs that any kind of port fuel injection. Seeing a lot of DI engines require spark plugs at 30-50k miles. Turbo engines definitely at the lower end of the spectrum.

The issue on DI engines is the spark voltage, which is higher to get the fuel mixture to ignite. The higher voltage is harder on the coil packs and the spark plugs.

Good luck.

[tracer bullet]

I changed mine around 45k miles a few months ago, they looked really good for color, didn't have any funny wear, and probably could have gone much, much longer. Did the coil packs while I was at it but also likely didn't need them. Drives exactly the same which was fine all along. I just had a rare chance to do some work on the car and went for it.

I can't see plugs changing with time like I could see a rubber belt or hose changing over time, or say the condition of coolant or brake fluid. I'd go strictly on mileage for plugs and at 20k not worry about it whatsoever.

As for the gap - I'm unsure. The new ones and old ones were the same so I left it. But I don't remember the amount.

[ClampThurst]

Did mine at 60k, they were slightly worn, noticed a bit smoother running engine after I replaced.