Spark Plug Question

[BlackThunder]

I definitely don't want to "spark" a big debate, but what brand style spark plugs is everyone running?

I usually go with the Volvo branded ones for my 2013 Volvo C30. But on FCP's website they are $89 vs Bosch ones for $33.

I'm at 126K for miles so it is time to change the plugs. Every 60K miles, right?

Also, anti-seize or no anti seize?

- Dustin

[matthew1]

$89!? W the F. It's a bit of ceramic and metal that industry has been producing for over a century. No moving parts, no computer chips, no space lasers, nothing remotely exotic.

I use a tiny dab of anti seize, yes.

source https://x.com/i/grok/share/2UJdX4b6HzeypShxb87rmhsx4

[precisionguesswork]

Modern plugs have a special coating on the threads and do not require anti seize. Using anti seize can cause over torque values when tightening them up.

Ive ran NGK forever. Pick a high quality plug manufacturer and inspect the plugs for any visible damage as well as double checking the gap and make sure the plugs have the correct reach and temperature range. It’s also very important to remove and install plugs when the engine is cold to avoid galling in the aluminum cylinder head. When installing plugs it’s always a good idea to install them using the socket and extension without the ratchet and spin the plugs counter clockwise until you feel the threads “skip” and then run them in until finger tight before using the torque wrench to avoid cross threading. You can also use some permatex dielectric grease on the inner rim of the coil rubber boot to help seal out moisture and to facilitate future removal of the boots. FCP has a nice video to demonstrate this.

Its also a good idea to clean out any debris/grit in the plug wells prior to removing the plugs.

[scot850]

Interesting, your comment on removing plugs when the engine is cold. I've often heard the reverse if the plugs are tight to remove. Being most heads are aluminum and plugs steel, the aluminum expands faster than the steel making them come out easier.

Not all plugs have the coating you mention, but with lifespans of plugs getting longer and longer, they can be a swine to get out. Using thread grease is I agree something you have to be aware of due to the possibility of over torquing. I reduce by 10%. There are arguments what you should reduce by, but in 50 years, never had an issue.

I think the reality is as Abscate has said, using more basic plugs and changing them frequently. Then you don't spend an hour getting a tight plug out as it is seized into the head. With the advantage of free replacements when you buy from FCPEuro, then maybe that is a good use of the replacement warranty, or do they insist on proof of lifespan they have covered?

Like the type of oil you should use, it can be an endless debate. Personally I stick to the recommended brands. Bosch for Volvo and NGK for my Toyota. However, I have no issue using either brand. Volvo parts are now getting so stupidly expensive it is getting harder to justify paying blue box prices. I think my last P2 set which were discounted were $125 CDN. However, the last set were replaced maybe 10 years ago with the mileage we do, I now look at age rather than mileage so they don't get stuck in the heads.

Neil.

[BlackThunder]

Cool. Thank you all! I'm at 126K so this will be the second time I've changed these. I ordered the Bosch plugs.

The Volvo plugs were too expensive. Hopefully I'll notice a difference.

Thanks!

Dustin