We install set of NGK OE-replacement coils and OEM Bosch plugs that we got from Sparkplugs.com on a BMW 335i running JB4 software.
Tested! BMW 335i NGK Coils and Bosch Plugs
By now you may have heard that BMW 335’s may have some maintenance issues. The ones I hear about the most have to do with a bad internal turbo wastegate as well as fuel issues—be it the pump or the Piezo injectors. Like with any turbo car, however, the ignition coils can take a hit, too. You know what it’s like when you mash the throttle, expecting to run away from the car next to you but your car starts to hiccup, spit and sputter, and you get left in the dust. It always sucks to be that guy because you probably want to lean your head out the window and scream, “No, no! I promise you this car is really really fast!”
An OEM set of coils can run you around $400, but fortunately for N54 engine owners, Sparkplugs.com now carries both Denso and NGK’s new lines of ignition coils for OE replacements. We decided to test a set of the latter on a 2007 BMW 335i that we had in the family, since it was misfiring badly in cylinders 1,2, and 3.
I had recently installed a set of these coils from Sparkplugs.com, along with a set of Bosch four-pronged plugs I had ordered from them, too, on a different 2009 BMW 335ix (all-wheel drive). The install went without a hitch. While that car wasn’t having as many problems as this one, the occasional hesitation during acceleration was reported. Like the current car we’re testing today, the other 335i had JB4 software, which about doubles the boost to around 14 PSI.
Testing the all-wheel-drive car for a baseline with a third gear pull, I couldn’t feel any hesitations. I performed the installation anyway. When I went back and retested a third gear pull from 30-100mph, the difference was a gain of 0.1 second. Just for fun, because the car felt so good, I even tested a quick 0-60 MPH, and with just the software—everything else stock, including the air filter—the sucker pulled a 4.3-second rip to 60 on my first try. This car is also an automatic! Later, the owner took my PerformanceBox VBox and recorded a couple of 4.1-second blasts to 60 MPH. With all-wheel-drive, that car is no joke. It’s now been 3 months since that car’s installation and so far, so good—not one misfire has been detected.
Today we’ll be performing the same test and see what we get on this rear-wheel drive 335i. We also perform a third-gear rip from 30-100 MPH to see if there is an improvement, which you'll see on Page 8!
Today we’ll be installing a set of NGK OE-replacement coils and Bosch OE sparkplugs that we ordered from our friends at Sparkplugs.com. This is a much cheaper route than going thru the dealer, which can charge you even over $800. Since we’ll be doing our own labor, today’s installation would cost you around $335 shipped from Sparkplugs.com.
With these BMWs, when coils start to go out, random misfires will trigger a “Service Engine Soon” or a full-blown “Check Engine” light.
The random misfires were confirmed by our Actron Elite automotive scanner.