DIY: Spark Plug Change
Moderators please move this to the DIY section.
This DIY is for a spark plug change on a 2007 E92 328. This model doesn't require the plug adapter like the 335. (If you have a 335 please purchase the adapter before attempting.) Other models may have different parts and procedures.
I used Bosch plugs from ECS Tuning. The stock plugs in my 328 were NGK. Expect to pay in the $70-100 range for six plugs.
This DIY takes approx. 2 hours given the amount of parts removed to get to the plugs.
8mm socket & ratchet
T30 torx driver or socket
5mm Hex socket or driver
Various flat tip screwdrivers.
Standard 5/8 spark plug socket
long ratchet extensions
Lubro Moly copper anti-seize (or other anti seize) Optional.
Possibly long needle nose pliers
Start by removing the six bolts from the interior carbon filter case and remove the case. (good time to change or blow out the filter)
Pull the edge of the cowl weatherstripping and remove the entire piece.
On each side of the car you will see two black cases. On two sides there will be rubber tabs. Pull these tabs back far enough to pull the rubber seal out from under the case. Two on each side, four total.
Find the sensor located on the cowl. There is one on each side. Carefully turn the sensor to unlock it from the holder and pull straight up on the wire clips. Set both sensors to the side. (Pic is of the passenger side, the drivers side is slightly different)
At this point you will be able to remove the plastic covers on each side. There are no screws or bolts, only plastic clips. Take your time so as not to break the clips.
Carefully unclip the tabs of the center hose/wire cover. Remove the top of the cover.
Unclip the hose and wire, pull them over the front of the plastic carrier and lie them across the engine cover. These hoses will be lying in the middle of where you are working for the remainder of this job. Remove other pieces slowly so you don't snag and pull them.
Once the hoses are clear you can remove the lower portion of the plastic holder. You may need a flat tip screwdriver to depress the tabs. The holder will pull straight out towards the front of the car.
Once the first holder is out of the way you will see a larger hose still connected to the cowl. Pull straight towards the front of the car to remove the plastic mounts. Once they are clear of the cowl, unclip the hose and remove the plastic holder.
Once all of these pieces are out of the way you can remove the large plastic cowl cover. There are two bolts on each side of the cover. Once the bolts are removed pull up on the front of it,
and then straight forward towards the front of the car to remove it. The back has rubber pieces that wedge around the rear frame. (Mine was pretty tight coming out, and kind of a pain going back in)
Now you should be able to remove the engine cover. There are two hex bolts on the front/top of the cover, another on the back/top and one that is hidden on the back lower passenger side. See the driver in the pic.
Once you get the engine cover off I would recommend either vacuuming or blowing off the ignition coil area. Mine had lots of dust and debris around the coils. You don't want to risk any of this debris falling into the plug holes.
At this point this is a basic plug change but I'll continue through....
My technique is to pull each of the coils loose first, but don't completely remove them yet. These coils will be pretty tight and it is hard to get a grip on them sometimes. You can use different methods such as the grip pads you'd use to open jars. I just hook my two fingers around the top and my thumb around the back and wiggle it until it pops loose. Resist the urge to pull up on the wires, you could pull them loose form the coil.
This silver cylinder makes it difficult to get the #3 and 4 coils loose. The proximity of them makes it hard to get a good grip on them. Be patient, they will come out with the cylinder in place.
In order to actually pull the coils completely out you'll have to remove the wire harness from it's clips. Just work it slowly out and down. Pull straight up on the small yellow and gray box to remove it from it's holder. (screwdriver for picture purposes only, don't use sharp objects around the wires)
Between the #4 and 5 coils the wire harness is secured with a plastic clip. Squeeze the clip on either side and pull straight up on it to remove it. On either side of this clip you'll see that the wire harness is secured to the base with two zip ties. Since you can't get the #5 coil out without removing the wire harness I cut the two zip ties. If you choose to do this be very careful not to cut the wires. I chose not to replace the zip ties as I couldn't see that the harness was going to go anywhere with the clips around it. If you chose this, remove the old zip ties so the sharp edges don't rub the wires.
At this point all of the coils should be loose and resting in the plug holes. Once you start to replace plugs you'll want to remove one coil and replace one plug at a time. I found that the #2 and #5 coils were the hardest to get out of the plug holes since they are bound fairly tight with the wire harness (even with it loose). Be patient and work them in different directions until they are out.
Use your plug socket and a socket extension to break loose the first plug (start with #1, my pic is of #4). The plug will likely be very tight and hard to break loose initially. Slowly turn the extension until you can remove the plug.
Open all of the new plugs and put some of the anti-seize on the threads. Don't go down too far on the plug with the stuff. I realized after I took the pic that there was way too much compound on my plug and I wipped some of it off. The anti-seize is optional but it will make it easier to remove the plugs when the next change is due. You can also use plug grease on the tops of the plugs if you wish. This will aid in the coil removal. The pic has the old plug on the left, new on the right.
Insert the new plug in the socket and guide it down the plug hole. Be very careful to keep the socket straight so you don't cross thread the plug. Turn gently until it catches and tighten it. Check the torque specs for your particular car. Over the years I have just always hand tightened spark plugs without any issues. Be sure not to over-tighten as you run the risk of breaking the plug.
If your socket is anything like mine it will want to stay on the plug when you pull the extension out. I had to use long needle nose pliers to retrieve my socket from the plug several times.
You'll need a shorter extension for #5, as the strut bar passes right over the top.
Once you have completed all of the plugs, reinstall the coils. You will hear a definite pop as it sets back. I would highly recommend that you fire up the engine and check for proper function prior to reinstalling all of the trim parts. Re installation of everything is in the same order as removal.
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