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DIY Spark Plugs, as requested. (Pics inside)

108K views 140 replies 85 participants last post by  Edgy36-39 
#1 ·
A few people asked for a small write up, so here it is! The job itself is not very hard, just takes a little time and some small hands. I am not responsible for any damage you do to you engine or yourself. This is a high voltage system, use common sense and disconnect your battery.

Tools:
3/8'' Rachet
LONG 3/8'' Extension
3/8'' Wobble joint
10mm Socket
Spark Plug socket
Torque Wrench
Flat head screw driver
New plugs, NGK or Bosch are the BMW choice from the manual
Lots of light
Gloves
Liquid refreshment
A girlfriend/wife with small hands (If you have giant monster hands like me)

I started with the passenger side first. In order to access everything the cabin filter and its plumbing need to be removed. Zee Germans did a very nice job of making this unit easy to remove. At the center of the filter tray there is a small metal clip that holds the entire unit to the strut tower. Pull this clip out and set aside. Now lift the long, thin black bar that holds the filter lid on. Remove the lid and filter and set aside. Now to disconnect the plumbing into the firewall. On the filter box end, there are 3 tabs on the connector that need to be lifted (I choose a small screw driver but your fingers will do) The filter box and plumbing should now be separated. To remove the tube from the firewall rotate the entire tube clockwise, then it will pull straight out. To remove the filter box lift it from the right side. the box has a tab that sits in the fender and will pull right out when the right side in angled upwards.

You should have an area like this when finished


Parts that were removed look like this


There are two 10mm nuts on the surface of the access cover that need to be removed. Take care are not to drop the nuts or their washers into the engine bay! Once these bolts are removed the cover can be lifted (with a little force) and then maneuvered out of the engine bay. Be gentle and just wiggle the cover out, it will come, it may take some different angles.

You should see this


Now for the Bremi's (coils). I found it best (after trying many different ways) to remove all connectors first. To remove the electrical connector from the bremi takes the following: There is a large metal retaining clip that holds each connector in place. I found it best to use a flat head screwdriver, insert in the small recess at the front/long side of the clip and just "pop" the clip up. Then with your fingers lift the clip as far up as you can (it will stop, you won't pull it off). These clips are a pain in the arse because they always want to work there way back down, so with one hand hold the clip up, and with the other slide the electrical connector off the bremi. Repeat this process for all 4 bremis. The last one (closest to the firewall) is a PITA but take your time, just move the rubber insulator as best you can to access the connector. With the electrical connectors off I then removed the two 10mm nuts that hold the black, plastic wire loom in place. With the all of the above mentioned removed it makes access to the bremis very easy.

On to the Bremis. There are two 10mm nuts that hold each bremi in. Start with the first bremi, remove the nuts (again be careful as not to drop the nuts down into the galley) With the nuts removed get two fingers under each side of the bremi and give it a firm tug straight out. Remove the bremi and set aside.

Cover off and the first bremi out


Here is a pic with a bremi out, it is the driver's side but you getb the point


With the bremi out, use a very long 3/8'' extension, a wobble joint and your spark plug socket to get the plug out. Try to turn the plug as true to center as possible. This is hard because of the angles required to access the plugs. Remove plug and number. Reinstall new plug and turn in with FINGERS ONLY (ie remove the racket and turn the extension with your hands) this will ensure the plug seats true and not cross threaded. These are aluminum heads, not hard to f up. Once the plug is turned down by hand grab your torque wrench and tighten to 21-22 ft/lbs. Again keep your extension as true to center as possible. Reinstall the bremi and your done your first plug. I again suggest leaving the electrical connectors off to better facilitate access to the remaining units.

Work your way rearward. The last plug is a bit hard to access, but use your head and take your time.

After you change all 4 plugs, put everything back together in reverse order. Again the plug closest to the firewall is just a PIA.

I am not going to post about the drivers side because it is 99% the same as the passenger! There are a few AC hoses that are in the way, so small hands work better.

Button everything up


Start her up and enjoy! Make sure you get all your tools out of the engine bay!! Label your old plugs and post pics on here so smarter people can analyze them for you :biggrinbounce:
 
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#61 · (Edited)
Very useful post, I'll be doing mine. Thanks.
Anyone know if the Denso Iridium IK20 plugs are a decent alternative?
 
#62 ·
I would just stick with what the factory recommends.

-Ryan
 
#63 ·
Running with oil on plugs?

So I finished installing my spark plugs on the side that had oil on them (driver's side). I then took the M5 out for a spin to see if everything was ok. Had a bit of white smoke (figured it was the oil burning off the plugs) coming out of the engine bay on startup, but other than that, everything seemed to be tip top. Later that evening, I read Doug's response and did a bit of the good 'ol search (sorry guys, should have done a better job the first time - BEFORE asking). Anyway, it seems I got leaky valve cover gaskets. I plan on installing the valve cover gaskets in the next week or so. My question is: should I go ahead and replace the spark plugs on the leaky side to be safe (I just installed new ones, but oil has obviously gotten onto them)? Do the coils need to be replaced as well (they also had oil on them, but are not new)? I was planning on using some MAF cleaner and whatever type of non corrosive degreaser to clean the parts during my gasket install, but I didn't know if I should just spring for another set of new plugs and a set of coils, or if my current stuff would be okay... Anyway, thanks again for all the great help on this board. The DIY spark plug job was cake with this thread!
 
#65 ·
So I finished installing my spark plugs on the side that had oil on them (driver's side). I then took the M5 out for a spin to see if everything was ok. Had a bit of white smoke (figured it was the oil burning off the plugs) coming out of the engine bay on startup, but other than that, everything seemed to be tip top. Later that evening, I read Doug's response and did a bit of the good 'ol search (sorry guys, should have done a better job the first time - BEFORE asking). Anyway, it seems I got leaky valve cover gaskets. I plan on installing the valve cover gaskets in the next week or so. My question is: should I go ahead and replace the spark plugs on the leaky side to be safe (I just installed new ones, but oil has obviously gotten onto them)? Do the coils need to be replaced as well (they also had oil on them, but are not new)? I was planning on using some MAF cleaner and whatever type of non corrosive degreaser to clean the parts during my gasket install, but I didn't know if I should just spring for another set of new plugs and a set of coils, or if my current stuff would be okay... Anyway, thanks again for all the great help on this board. The DIY spark plug job was cake with this thread!
Your coils are fine, and as mentioned, so are your new plugs...

d-
 
#64 ·
Can't see that much oil would get in over a week, just clean it up.
 
#72 · (Edited)
I vote no anti-seize myself for 3 reasons:
1). The factory doesn't use it.
2). I don't want to guess what reduced torque value to use.
3). Sparkplug threads are coated with (Cadmium?) which does not react with aluminum. They won't rust or otherwise weld in place.

If you just can't live w/o anti-seize I wouldn't even torque 'em down. The NGK box shows a process for tightening them down. IIRC its 2/3rds of a turn from when the compressible gasket makes contact with the head (when HAND tightening). From there 2/3rds of a turn compresses the gasket fully and the power needed to turn the plug further rises VERY fast. When I used a torque wrench on mine (no anti-seize and 18ft/lbs) the wrench always clicked right around 2/3rds of a turn. I'd use this 'distance' over a torque value if I were to use anti-seize. In fact its pretty spot on with dry threads as well.
 
#75 ·
If there's enough room, head to an auto store, and get a telescoping magnet, looks like a pencil with a magnet on the end, and can telescope.

Unless the washer is aluminum.....
 
#76 ·
Happy New Year!!! My fellow M5 Board members. I am undertaking some maintenance including spark plug replacement over the course of the winter. My M5 has 90k on the clock and curious if it would be an opoprtune time to replace the ignition coils and boots. The car idles like a contented cat purring and just doing as PM since I don't have complete records from the previous owner. I'm new to performing my own maintenance, but find I don't trust many repair places to do the work correctly nor can I afford to pay their prices. I have ordered a Peak Reader to check any codes and will post pics of the plugs when I change them.

I look forward to your comments or suggestions.

Ken
 
#77 ·
Coils and boots are not really a PM item for most people. I would suggest that you replace the spark plugs and compare how the engine runs afterward. From what I've read on this board, even people who replace the coils only do so for individual cylinders...not all 8. Have never priced them but Id guess they are somewhat expensive.
 
#78 ·
Big thanks to the original OP, it made things soooo easy! I was pleasantly
surprised at how maintenance friendly the job was. 60 minutes, start to
finish.

BTW, I use anti-seize, always have always will. it will make next January's
maintenance just as easy. And I don't use a torque wrench on the plugs
either. After 30 years of wrenching on bikes, boats, cars, trucks, planes
and helicopters I fairly sure I can avoid screwing the pooch on this. To each
their own.
 
#79 ·
One thing that no one's mentioned is that it's a good idea to remove any dust/grit/debris from the spark plug holes and surrounding area to eliminate the chance of it getting into the cylinders.

I do this with some compressed air, blasting the area whilst the plugs are still in the head but backed out a couple of turns.

I realise that the spark plug area isn't exposed and doesn't get particularly dirty but it doesn't take much grit to damage the bores. Mine had a bit of grit in that area, I was glad I blasted it away.

If you have access to a compressor or even those computer air blasting cans, I'd recommend doing it.

Also, check to make sure the 'seat' for the compression sealing washer is free from debris before fitting the plugs, to ensure the best seal.

A wet swab or long cotton bud is ideal (carb cleaner or similar). Just don't drop one into the cylinder!

As for the torque, I'll use the 1/2 to 2/3 of a turn with new plugs and feel with re-used ones. I've heard 10lb.ft used as a torque setting, but feel is just as good.
 
#81 ·
Ger, I've just reviewed this thread for the nth time and wondered if anyone had mentioned the clearing out the plug holes before plug removal. Various oil leaks can drop oil into the plug holes, meaning even if it is a 'clean' area, any dust or grit will have been held in there. Just a quick extra step if you're a complete perfectionist, any sort of compressed air, can or compressor, should quickly clear anything out. Just be careful it doesn't come back into your eyes ;)
 
#83 ·
This wasn't a very intensive job, however it did take me a while because I was running to the store to buy new tools and such (1/2 to 3/8 adapter for torque wrench for example..). I had 2 problems while installing the plugs. They were that I accidentally crushed one of the brown wires under a bremi and that I had a VERY difficult time getting the driver side cabin air filter back in place. Does anyone know if the crushed wire is going to cause any problems later on? It is almost completely flat in one place. I started the car and it idles better but am unsure of true results. I currently cannot take it on the test drive as the fuel is low because I'm replacing the regulator housing on the fuel filter with an oem one due to a leak (long story...). Doesn't really take small hands just a little ingenuity and brains (My hands are huge). Having the right tools makes the job as easy as it is supposed to be. I would not attempt this job with half-a*!ed tools or improper research. I torqued the plugs to 21 ft/lbs with a needle torque wrench and I did not use an anti-seize compound (they were quite snug but not too tight). Cleaned the bay as I went. My M5 has just a hair over 60k miles and the plugs were fouled worse on the passenger side than the drivers side. I believe I have a leaky valve cover gasket because there was a little oil in the driver side near the 2nd and 3rd plugs. I sincerely appreciate you taking the time create this DIY as this saved me hundres of dollars from the $tealer ($22-$24 per spark plug pluse 2 to 2.5 hours worth of labor @ 100/hr, gtfo). I ended up purchasing my plugsx6 from pep boys for $7.99 each and x2 from Advance Auto Parts for $9.09 a piece (DO NOT PAY ANY MORE THAN THIS!).

If anyone has any idea if the crushed wire will affect anything please let me know. Of course I removed it from under the bremi. I started the car with no problems other than that fuel filter housing with the leak... TIA, Khalid.
 
#85 ·
Did this last night. Actually was a breeze, except bending over the fenders does wear out your back.

Tip: i used a magnetic pickup to catch the 10mm nuts once I loosened them. No worries about dropping them since the magnetic grabbed it as soon as it was freed.

My plugs looked similar to the others I've seen in this post. I'm replacing all the wear items since purchase. I did notice the car go into limp mode when I took it to redline prior to the plug change.

My next steps are:

Fuel filter
All four o2 sensors
Clean mafs and test.
 
#88 ·
Just to be clear, I suggested blowing air to remove any grit etc whilst the plugs were in the engine but backed out a turn or two, so that nothing would be able to enter the engine.

I'd never think of blowing any air about with the plugs removed!

If there's any liquid in there, use some paper towels (eg kitchen towels) to absorb it first, again whilst the spark plugs remain in. To really get them clean, use swabs dipped in some parts cleaner, the long 'lab' types are ideal.

HTH.
 
#90 ·
Thanks to this fantastic thread, the boy born with two thumbs on each hand was able to change his M5 spark plugs, and still have all the skin on the back of his knuckles :) Sure, it took almost 3 hours, but I went slow so as not to drop anything into the engine bay, and I tried to enjoy it. I can only think of one other thing I'd rather be doing on a Saturday afternoon than "swapping out the plugs on my muscle car", and she was out with friends, so that wasn't happening :)

I have attached a picture of the last plug being pulled with the Bremi's attached (Driver's side) to show the kind of room available if you leave the wiring all hooked together. Thanks again all!

 
#91 ·
Another vote of thanks from me!

This was the first job I decided to tackle on this engine, which is a far more complex beast than anything else I've had over the years. Nothing desperately difficult, just needed a steady approach.

A few thoughts in the hope that it might help others:
A 1/4" drive ratchet with 2" and 6" extensions are ideal for getting to the 10mm nuts holding the Bremis; I used this as an excuse to buy myself a decent 1/4" Britool set which I've been meaning to do for a long time. ("Think of the money I'll save.....")

Access to the rear is easier with the cabin air filter box and snorkel removed, and when refitting the plug cover it allows you to see it locate properly over the large rectangular wiring grommet.

I had no problems with any of the plugs using a 3/8" drive UJ plug socket with a separate 12" extension - I used that for all of them. I couldn't get hold of a long extension UJ plug socket in 3/8" drive, or I'd have used that; as it was the tip on taping the socket and extension together was very useful. You don't find out until you try and remove the socket from the plug and the socket stays behind as the rubber insert in the socket grips really well on the plug....... The only option then is to undo the plug and take it right out again to get the socket off - a PITA if you've just torqued it! I ran a couple of turns of electrician's tape on the shaft of the extension and then down onto the plug socket - that held good for all 8 plugs.

My biggest nightmare was dropping those little flange nuts holding the Bremis. My first approach was using one of those flexible shaft magnetic pick-up tools (I drop lots of stuff, so I've had it a while), holding it in one hand and resting the magnet end in the other hand that was removing the nut; when I felt the nut come off the thread I just had to move the magnet a fraction with the other hand to grab it. It worked for the bolts and washers holding the Bremi earths as well. Getting the nuts back on provides even more opportunity for dropping one, and eventually I realised that what I really wanted was a magnetic 10mm socket. Which I don't have. But I do have some small rare earth disc magnets, and one of those fitted perfectly inside the 10mm socket - problem solved. After a bit of faffing I realised that the best way to get the disc magnet to go flat into the socket was to push something through from the back of the socket - I used a phillips screwdriver as the first thing that came to hand - and use that to stop the magnet twisting as it goes in. Much easier than it sounds. With an extension in the socket you can then start and run the nut easily with your fingers without risk of dropping it. Using the short extension, even if it wasn't needed, gave something more positive to grip; otherwise I guarantee I'd have dropped the socket with nut still in it.

Don't really know how long the job took as I wasn't in a hurry, but it was actually quite enjoyable.

Thanks again to everyone for making it easy!
 
#93 ·
Good Thread!

I didn't read a few of the pages, but I also dropped a grounding bolt prior to doing this ouich but if you tear a piece of paper towel just a bit bigger than your 10mm socket, hold it over the socket hole and then insert the nut/bolt into the socket with paper towel in the middle, that will hold on the the nut/bolt. Very handy trick to use that I waited until I dropped one and had to jack up the car and search the underpans with my telescoping magnet . . .

Nicely, now my car isn't as jumpy/sensitive at about 1700 RPM :cheers:
 
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