E46Fanatics (http://forum.e46fanatics.com/index.php)
-   ///M3 Forum (http://forum.e46fanatics.com/forumdisplay.php?f=65)
-   -   M3 Spark Plug Life? (http://forum.e46fanatics.com/showthread.php?t=959604)

TramRam 12-06-2012 11:46 PM

M3 Spark Plug Life?
I got my M3 with 80k on it and according to the previous owner, the plugs have not been changed. What is the typical mileage when there's benefit to replacement? I've checked and found no posts on this subject but know that plugs on 'newer' cars are typically intended to not need replacement for 100k miles. Maybe I just HAVE to mess with :censor: but I know how good fresh plugs feel in a nice engine and can improve mileage at the same time! I'm lucky to get 16 -18mpg in in town with some highway driving each week and think I can do at least a little better! I get about 24mpg at highway speeds of 75mph on a long highway run. This is calculated mileage not what the gauge says.

Arock1092 12-07-2012 12:29 AM

80k on an m without replacing spark plugs.(yikes).. I did mine with inspection 2 at 60k, get them done asap!

jayb328i 12-07-2012 06:08 AM

Nope--would not wait until 100k. I would change at 80k. You need to look at each plug to verify its condition, and I would not go through that effort without just changing them and netting possible better performance. PS--also once had a plug that seized in place (no anti-seize coating) --would want to change at 80K or sooner.

shanneba 12-07-2012 07:25 AM

The BMW suggested plug change interval for the E46 M3 is 60,000 miles.
It is also the the interval for the valve adjustment, Transmission and diff fluid changes for the M3.

You can download the BMW Service checklist here:

Owners manuals are here if you need one:

steve bettencourt 12-07-2012 07:25 AM

I would say for shure 80km is 50 miles I changed mine and you will see a difference

TerraPhantm 12-07-2012 07:28 AM


328ci906 12-07-2012 09:51 AM

60-100k is what I've read as well. It's on my maintenance list for this spring.

McGary911 12-07-2012 10:54 AM

I did mine at about 62k, shortly after I purchased the car, as I didn't know if it had ever been done. It's easy to do in an hour, and the plugs while a bit pricy for plugs.....won't break the bank. Mine looked pretty good when I took them out, but feel better knowing there are 6 fresh ones in there. I took the opportunity to clean the parts of the engine that I exposed during the work, so not only did I get new plugs which I can't see, my engine bay looked a lot nicer.

TramRam 12-07-2012 11:29 AM

Thanks for the good feedback guys & the links Shanneba. In time, I'll hopefully be able to FEED the forum more and glean less. From the way my car drives, my guess is that all is in decent order but you don't know what you don't know until you do know! I've got a fresh set of plugs sitting, waiting to go in now. As far as using anti-gallant on plug threads, I've always just used some fresh motor oil and never had any extraction issues even on high HP turbo applications.

illestminimike 12-08-2012 12:21 AM

I have mine sitting in my room. I'll change them one day.

djantlive 12-08-2012 12:31 AM

you can always pull one out and see if it is in bad shape before you buy and replace all.

TramRam 12-08-2012 11:45 AM

Hey, with 80 kmi on them now, they are coming out!!! The ones I determine to be in the best shape will go on the 'just-in-case' shelf and I'm done and SHOULD be good for another at least 60k! Might be into another M by then...possibly a 5! Heading out to my buddy's shop right now to do its 1st oil change (with Redline 10w60) and plug replacement (NGK Iridiums) since taking ownership of this sweet machine!

All times are GMT -5. The time now is 05:28 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use