[Fat Panda]

I've been getting mixed responses regarding when the spark plugs should be replaced on the N55 engine. I've read that the replacement interval should be sooner since direct injection is harsh on the plugs.

I've seen 25,000km (16,000mi), ever 2nd oil change, or 60,000km (37,000mi).

How often should N55 engines have their spark plugs replaced?

[_bdiddyb_]

No manual for the F30 yet. So, a reliable source that I trust is BavAuto dot come. They had the 3 series E90's at 60K/4yr. My 2013 335 is NOT a lease, so I just changed out the plugs myself at the 30K miles mark. From the pix, #4 and #6 would probably go first but I'm not waiting till 60K/4yrs to find out.

[IMG][/IMG]

[Polo08816]

Originally Posted by _bdiddyb_

No manual for the F30 yet. So, a reliable source that I trust is BavAuto dot come. They had the 3 series E90's at 60K/4yr. My 2013 335 is NOT a lease, so I just changed out the plugs myself at the 30K miles mark. From the pix, #3 and #6 would probably go first but I'm not waiting till 60K/4yrs to find out.

[IMG][/IMG]

You would be my hero if you had a DIY guide for this.

[Fat Panda]

Thanks for the picture.

Pretty much every second oil change on BMW's factory interval. I wouldn't want to wait either. I prefer preventative maintenance over on demand maintenance.

[drexplode]

What is your driving behavior like? Short trips where the engine doesn't warm up completely is bad for spark plugs / carbon build-up. Every once in a while perform a Ferrari tune-up: WOT / high load.

I performed a spark plug replacement on my E90 335i (N55) at 16k miles after CPO purchase for piece of mind. Check out one of the plugs:
http://www.e90post.com/forums/showthread.php?t=864258

Your plugs don't look too bad.

[harkes]

I got problems with misfire after 28000mls - plugs was the problem.

[DrivenByE30]

From the BMW service manual:
- 30,000 miles for 328i
- 60,000 miles for 335i

I am planning to do this within the next two weeks.

Will report back.

[CarlosC]

I replaced the spark plugs on my 328i a couple of months ago. I would think N55 is similar, but I can't confirm. You'll need a 14mm, thin-walled spark plug removal socket - like this (there's cheaper ones on eBay) but this is the one I used.

For 328i/N20: Basically, disconnect the battery (not necessary, but just to be safe), then disconnect the two plug-in cables on the left side directly under the engine cover (plastic cover with BMW logo). The engine cover then just pops out (pull up at the corners). Carefully remove the rubber acoustic molding over the engine - its not attached to anything but its very form-fitting, so remove it carefully, pulling upwards. Once that's off, you'll see the ignition coils. Disconnect the snap-in cable connected to the coil and then pull the coil straight out (I stuck a screw driver in the coil horizontally and pulled up), you'll hear a slight pop sound when it comes out. You'll then see the spark plug below. Remove the old plug and torque the new one to 23nm, reinsert the coil (make sure is firmly inserted all the way down) and make sure the snap-in cable for the coil is attached securely.

Its all pretty easy until you get to the plug closest to the rear of the engine (if you're standing in front of the car). That plug is hard to get to because there is very low clearance to work with. I used two locking 3" extensions to get to it and it took me a little while, but I was finally able to get it out and put the new one in. Again, make sure all the ignition coils and their snap-in cables are firmly attached. Reattach the acoustic rubber foam piece over the engine and snap back in the engine cover. Plug in the two cables on the left side under the engine cover and reconnect the battery. Assuming you've done everything correctly, you're good to go!

[xxxjecxxx]

I've just replaced my spark plugs on n55. You need a special spark plug socket to be able to do the job. I had to put everything back together until the socket came in. Other than that, it's pretty straight forward. I believe it's the same thing with the N54.

http://www.amazon.com/gp/product/B01...ilpage_o04_s00