cokeefe

This is a medium-difficulty project, probably about a 3 on a scale of 10, where 1 is putting air in your tires and 10 is doing an engine rebuild using only a set of Harbor Freight adjustable wrenches and a box of toothpicks, with ?assistance? from my two year old son.

It?s not technically challenging, but there?s limited space to work. So have your magnet on a stick standing by, and be prepared to pull off the plastic undertray if you do drop a tool down into the abyss. It helps if you stick some shop towels into the area before you start dropping tools in there.

Step 0 ? What you need

You?ll need about 2 hours of free time and the following:
8 Spark Plugs: Bosch FR7KPP332 or equivalent. The FR7KPP332 is the non-BMW stamped version of exactly the same plug the factory put in the car.
Feeler guage or spark plug gapping tool
Sockets:
5/8 (16mm) spark plug socket. The one with the rubber inserts that grab the plug are the best
10mm socket ? it helps to have deep and shallow versions
Various extensions (see picture)
5/16 12-point socket OR Torx socket




Step 1 - Remove the engine cover and the two plastic coil covers (10mm Socket, 4 nuts)

BMW knows that the sight of a naked engine offends just about everyone, and therefore covers it up with lots of nice-looking plastic. Undo the four 10mm nuts on the top cover, then pull the cover straight up off the studs. Then pull off the two plastic coil covers, one on each valve cover. They are just stuck on with a friction-fit, no hardware. Stick all three pieces on a shelf so you don?t step on them.





Step 2 ? Remove the coil hold-down clips (5/16 12-point socket OR Torx socket)

Take a look at the valve cover area, and you will see that each coil is covered up by a clip. There are two clips on each valve cover, and each clip covers two coils. Each clip is secured by a single Torx bolt (highlighted in the picture). The Torx bolts are pretty loose, almost hand-tight. If you have the proper Torx bit, great. For the rest of us, a 12-point 5/16 socket works fine and will not damage the bolt if you take it easy. Remove all four clips from both sides of the engine. Notice that they are marked ?Front? so that you put them back on the right way.



Continued next post

cokeefe

Step 3 ? Remove the 6 Coils that can be removed by normal humans (Small Allan Key if needed)

Now it?s time for the real fun to start. You can take out six of the eight coils with minimal problems. It?s the two coils closest to the firewall (passenger compartment) that are going to cause all the swearing. Go ahead and remove the six that are easy, just to get yourself in an optimistic frame of mind. Flip up the plastic clip on each coil until the electrical connector is disconnected. I had to use a little Allen key to get some leverage, but the clips are tough and didn?t bend or break. Pull the electrical connectors out of the way, then just grab the coil and pull it straight out. It?s surprisingly long, maybe 5 inches or so. For the anal retentive among us, put the coils on your workbench in the right order, so each goes back into the hole it came out of.






Step 4 ? Remove those two #$*%^@ rearmost coils (10mm socket, Small Allan Key if needed)

They are not hard if you remove a couple things out of the way to get some clearance. On the right (passenger side in the US) cylinder bank, you need to unbolt and slightly move an air conditioning bracket and refrigerant line. This involves taking off the two 10mm nuts ? they have captive washers, so the washers will stay with the nuts. Then pull the whole bracket off the studs and maneuver it down so it is stuck below the studs. Be aware that there is a brass bushing inside each rubber mount ? don?t lose these! Now you will (barely) have enough clearance to get that coil out. It seems impossible at first, but just keep wiggling the coil around until you free it.
On the left side (driver side in the US), you need to unbolt a small battery cable hold-down bracket (1 10mm nut), then move the red cable out of the way. Be aware that the nut is plastic, and don?t overtighten it and strip it out when you put it back on. Remove the coil. There?s a fuel line spanning across that area, so don?t get too carried away wiggling that around.

Passenger side



Driver Side



Step 5 ? Now you?ve got to keep going, because you can?t drive your car. Remove the plugs. (5/8? spark plug socket and various extensions)

Remove each plug by turning counterclockwise and unscrewing it. Keep them in the correct order as you lay them out on your workbench. If one of your cylinders has some sort of combustion problem, it will show up on the plug. All the plugs should look similar.

Step 6 ? Double check the gap and install the new plugs. (Feeler guage / spark plug gapper, 5/8? plug socket, extensions)

Using your feeler guages or a gapping tool, double-check the gaps on your new spark plugs. The spec for the Bosch FR7KPP332 plug is 1mm (0.0394 inches), and all of mine were dead-on correct when I measured them. Do not use any grease, antiseize, spit, or anything else on the plug threads ? that will mess with your torque values, and is unnecessary with an aluminum block engine.
Screw each plug into the engine, starting by hand until you feel it seat, then finishing with your torque wrench.
IMPORTANT: The factory?s torque spec is 30Nm +/- 3Nm for size 14x1.25mm plugs. You can tell the 550i?s plugs are size 14x1.25mm because of the ?F? code as the first letter in the plug?s model number.
The torque spec on the Bosch spark plug box is 28Nm. I went for 28Nm, which is 20.7 pound-feet. Be sure that your torque wrench is reasonably accurate, and remind yourself that you are acrewing those plugs into soft aluminum. If you strip the engine head?s plug threads, you'll be getting intimately familiar with a Helicoil kit, and there?s a reason Helicoil starts with ?hell.?

Step 7 ? As the old Haynes manuals say, ?Reinstallation is the reverse of removal.?

Put your coils back on, plug in the electrical connectors (you might want to start up the car at this point to make sure everything is correct), put on the coil hold-down clips, put the A/C bracket and battery cable bracket back in place, pop the decorative covers back on, then do some stretches so you don?t look like a hunchback anymore. Piece of cake.

Step 8 ? Post-game show

This is what all my plugs looked like. For comparison, a new plug is on the far right in the first picture, and closest to the camera in the second picture. None were in terrible shape at 42K miles, but there was some wear on the electrodes. This is cheap maintenance, and who doesn?t want to spend a couple hours using tools?

turboawd

great write-up!

skelevirus

nice no error codes do u have to disconnect the battery first?

mnmike

I assume you used the recommended Bosch Platinum Plugs?

You can't gap platinum plugs (they come pre-gapped to the correct clearance).

Rizbel

Nice DIY .

Trinity Autosport

Nice write up. The first time I did it took me awhile as the engine was some what still hot...

Anyways since then I have done it 8x's? It's easy once you keep on doing it. I've actually used NGK plugs. Some cars have NGK some have Bosch.

theXman

Nice DIY. Great job!

530inOK

Thanks for sharing a great DIY! My car has the I6 but overcoming the fear of diving in is the same. Your old plugs have good color. Good fuel, oil changes at half the recommended interval, and
occasional injector cleaner additive is key.

buddy

Nice tuturial, just replaced mine in my car took about an hour only because the engine was hot and I only dropped one part that curiously fell directly into the slot on the engine mount and could not be retrieved. It was the rubber grommet off of the cover.

Have pic's and may upload if you guys want them they however are not as good as the previous poster.