DIY: How to replace ignition coils
DIY: How to replace ignition coils
03-03-2009, 08:18 PM
#2
Surf Hard, Drive Hard
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Alright, I agree there is no DIY for the coils, but it's really not that hard.
Here is some info. I didn't write it, I took it from another thread that I saw while searching "coil replacement". Took me all of about 2 minutes. I didn't read it in depth either, but sounds like he got it right for the most part.
Task:
Let the car cool down! (Mine was already dead, so not a problem) & write down your radio stations.
1. Pull off battery cover - careful, it's easy to break the plastic clips holding it on.
2. Use 10mm socket and remove negative terminal.
3. Pull out air filter box - this is a pain. Literally. I jammed one of the metal lid-clips into my palm. You have to push the front of the filter box towards the windshield until the oval shaped opening in the front clears the receiver in the bumper. Lift up in the back of the box a little, near the accordion tube, then push hard from the front while exerting upward pressure. Search Youtube for "removal Rx8 air filter" for a sweet vid of the filter box removal.
4. Remove the 2 wire harnesses from the back of the filter box and push out the wire-guide clips - tuck them out of your way. (Guide-clips are kind of a pain, but you can press the clips from the back w/ the screwdriver)
5. Loosen the hose clamp on the front of the accordion tube (between filter box and accordion) w/ the Phillips head.
6. Pull the filter box forward and out of the accordion tube - twisting L & R gently helps.
7. Under the filter box, Detach the odd black canister thing w/ the small hoses from the brass bracket and let it hang there - it just pulls off the bracket.
8. Done w/ filter box - You can now rotate it over and set it on top of the battery.
9. Loosen the hose clamp on the back of the accordion tube (between the accordion and the throttle body) w/ the Phillips head. The tube can then be gently twisted off. I didn't detach any of the hoses, just pushed it aside.
10. The 4 coils are now exposed below the throttle body - you can see the top connections of the spark plug wires - they plug right into the coils.
11. Start from the front and work your way back: Pull off the spark plug wire - they don't come off easy. (Note on 2004 models, w/ the old coil design there's a extension piece w/ a spring in it that will come off and remain stuck on the plug wire. You must remove this from the plug wire - it will expose the standard plug wire tip - ie a male connector that will fit in the female coil receptacle - if you're replacing the plug wires as well, don't worry about this)(Also note, you can unplug all the plug wires, but only do this if you mark them and remember which one goes to which coil - detonation is bad! very bad!)
12. Unplug the wire harness/connector from the back of the coil - clip on type, use the 10mm ratchet/extension/u-joint and unscrew the one retaining bolt that holds the coil to the backing plate. (Mine were corroded as hell, but a little constant pressure was enough to break 'em free)
13. The coil can now be pulled out. The very front coil is trapped under some sort of hose/mount guide - I just flexed the hell out of it until the coil cleared the screw post. The back one is also a pain to access unless you have a child handy, and is what makes the u-joint for the ratchet essential.
14. All the coils are the same, so you can just apply a little dielectric grease to the screw post (optional), drop the new coil in, bolt it down tight, re-clip the connector on the back, and plug in the PROPER plug wire. Repeat 3 more times.
(Note: Wiring is as follows: Starting w/ coil @ front of car and working your way back to the windshield: Coil#1. Leading front rotor, 2. Trailing front rotor, 3. Leading rear rotor, 4. Trailing rear rotor. On each rotor, the the lower/bottom spark plug is leading, the upper/top plug is trailing. Make sure it's wired right!)
15. Now undo what you did in reverse order. Twisting helps to reinstall the accordion tube and filter box into one another. Re-tighten the Phillips screws on the hose clamps. Reattach the black thing under the air box to the brass bracket.
16. You have to push really hard to get the filter box back in. Try not to impale yourself/crush your thumbs; then, once it's in, pull the box forward to seat it.
17. Remember to re-connect the two wiring harnesses to the air filter box.
18. Reconnect the negative battery terminal. Screw it down and replace cover.
19. Put the key in and turn it to "on" - don't start it yet. Reset all the stuff you need to. The DSC light will flash, and the Traction light will come on solid - this means you need to recalibrate the steering sensor (happens after battery disconnect) - see owner's manual: turn wheel clockwise to lock, then counter-clockwise to lock, then center wheel, then turn key to "off," then turn it back to "on."
20. Then give 'er a spin. If you did it right, you might notice significant low-end torque improvements (I did) and a more rapid engine start. Maybe even some mpg gains (I'm hoping - since I'm getting 11.8mpg, all city - but I've been driving on bad coils for a while)
21. If no start - check all of your connections, harness @ coils, battery, plug wires, intake harnesses.
22. Ideally, you should also change/clean your plugs (and maybe wires) at this time since the plugs are likely fouled due to poor combustion/misfire.
- I literally did this @ the dealership parking lot in 25 minutes; Thanked them for their accommodation and proceeded to drive my car off and pocket the $272 I saved in parts and labor for just the coils. Hope this helps!
Here is some info. I didn't write it, I took it from another thread that I saw while searching "coil replacement". Took me all of about 2 minutes. I didn't read it in depth either, but sounds like he got it right for the most part.
Task:
Let the car cool down! (Mine was already dead, so not a problem) & write down your radio stations.
1. Pull off battery cover - careful, it's easy to break the plastic clips holding it on.
2. Use 10mm socket and remove negative terminal.
3. Pull out air filter box - this is a pain. Literally. I jammed one of the metal lid-clips into my palm. You have to push the front of the filter box towards the windshield until the oval shaped opening in the front clears the receiver in the bumper. Lift up in the back of the box a little, near the accordion tube, then push hard from the front while exerting upward pressure. Search Youtube for "removal Rx8 air filter" for a sweet vid of the filter box removal.
4. Remove the 2 wire harnesses from the back of the filter box and push out the wire-guide clips - tuck them out of your way. (Guide-clips are kind of a pain, but you can press the clips from the back w/ the screwdriver)
5. Loosen the hose clamp on the front of the accordion tube (between filter box and accordion) w/ the Phillips head.
6. Pull the filter box forward and out of the accordion tube - twisting L & R gently helps.
7. Under the filter box, Detach the odd black canister thing w/ the small hoses from the brass bracket and let it hang there - it just pulls off the bracket.
8. Done w/ filter box - You can now rotate it over and set it on top of the battery.
9. Loosen the hose clamp on the back of the accordion tube (between the accordion and the throttle body) w/ the Phillips head. The tube can then be gently twisted off. I didn't detach any of the hoses, just pushed it aside.
10. The 4 coils are now exposed below the throttle body - you can see the top connections of the spark plug wires - they plug right into the coils.
11. Start from the front and work your way back: Pull off the spark plug wire - they don't come off easy. (Note on 2004 models, w/ the old coil design there's a extension piece w/ a spring in it that will come off and remain stuck on the plug wire. You must remove this from the plug wire - it will expose the standard plug wire tip - ie a male connector that will fit in the female coil receptacle - if you're replacing the plug wires as well, don't worry about this)(Also note, you can unplug all the plug wires, but only do this if you mark them and remember which one goes to which coil - detonation is bad! very bad!)
12. Unplug the wire harness/connector from the back of the coil - clip on type, use the 10mm ratchet/extension/u-joint and unscrew the one retaining bolt that holds the coil to the backing plate. (Mine were corroded as hell, but a little constant pressure was enough to break 'em free)
13. The coil can now be pulled out. The very front coil is trapped under some sort of hose/mount guide - I just flexed the hell out of it until the coil cleared the screw post. The back one is also a pain to access unless you have a child handy, and is what makes the u-joint for the ratchet essential.
14. All the coils are the same, so you can just apply a little dielectric grease to the screw post (optional), drop the new coil in, bolt it down tight, re-clip the connector on the back, and plug in the PROPER plug wire. Repeat 3 more times.
(Note: Wiring is as follows: Starting w/ coil @ front of car and working your way back to the windshield: Coil#1. Leading front rotor, 2. Trailing front rotor, 3. Leading rear rotor, 4. Trailing rear rotor. On each rotor, the the lower/bottom spark plug is leading, the upper/top plug is trailing. Make sure it's wired right!)
15. Now undo what you did in reverse order. Twisting helps to reinstall the accordion tube and filter box into one another. Re-tighten the Phillips screws on the hose clamps. Reattach the black thing under the air box to the brass bracket.
16. You have to push really hard to get the filter box back in. Try not to impale yourself/crush your thumbs; then, once it's in, pull the box forward to seat it.
17. Remember to re-connect the two wiring harnesses to the air filter box.
18. Reconnect the negative battery terminal. Screw it down and replace cover.
19. Put the key in and turn it to "on" - don't start it yet. Reset all the stuff you need to. The DSC light will flash, and the Traction light will come on solid - this means you need to recalibrate the steering sensor (happens after battery disconnect) - see owner's manual: turn wheel clockwise to lock, then counter-clockwise to lock, then center wheel, then turn key to "off," then turn it back to "on."
20. Then give 'er a spin. If you did it right, you might notice significant low-end torque improvements (I did) and a more rapid engine start. Maybe even some mpg gains (I'm hoping - since I'm getting 11.8mpg, all city - but I've been driving on bad coils for a while)
21. If no start - check all of your connections, harness @ coils, battery, plug wires, intake harnesses.
22. Ideally, you should also change/clean your plugs (and maybe wires) at this time since the plugs are likely fouled due to poor combustion/misfire.
- I literally did this @ the dealership parking lot in 25 minutes; Thanked them for their accommodation and proceeded to drive my car off and pocket the $272 I saved in parts and labor for just the coils. Hope this helps!
Last edited by Mazurfer; 03-03-2009 at 08:21 PM.
03-18-2009, 08:07 PM
#4
>> Motion
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Will I be able to reach my spark plugs if I take off my intake, because I plan on changing those also with the coils. Or will I have to take off my front wheel to get to it....
03-19-2009, 12:54 PM
#5
Certified Mazda Tech
No offense, and mine isn't going to be worded well as im going to rush this but that guide to removing coils is way too involved. I try to avoid pulling the airbox at all costs as it is a pain in the ***, also there's no reason to disconnect the battery, while a "standard procedure" for electrical work it's not really necessary.
All you really need is to remove the 10mm hose clamp on the square plastic box to the right of the TB, unclip the small plastic hose attached to it. Then remove the black box.
You'll be able to see the coils rather clearly. There is a clip for the harness attached to the coil mounting plate, with a firm one hand push downward it will bend out of the way of the first coil's nut making all 4 easily accessible.
Now remove the spark plug wires from the coils, easiest way to do this is (standing over the fender) rock them towards the front and back of the car, then with your hand on the boot using one finger grab the lip of the boot and try peeling it up while lifting the boot, this is to break the seal between the rubber and the coil (due to the heat they become semi bonded)
After that use a 1/4" ratchet with a decent size extension (i use an extension that reaches over the hoodline so i dont have to lean over at all, im just lazy) also a 1/4" swivel adapter and 10mm deep socket. May want to have a magnet handy to grab the 4 nuts when you remove them.
Now with the nuts removed you should be able to pivot the bolt hole portion of the coil up and over the stud, there will be enough slack in the wiring to pull it slightly towards you and make disconnecting the connector easier.
To reassemble proceed in reverse order.
Thats how i do it daily, makes changing all 4 coils about a 5-10 minute affair.
also remember the coils, from firewall forward, are t2,l2,t1,l1.
kevin.
All you really need is to remove the 10mm hose clamp on the square plastic box to the right of the TB, unclip the small plastic hose attached to it. Then remove the black box.
You'll be able to see the coils rather clearly. There is a clip for the harness attached to the coil mounting plate, with a firm one hand push downward it will bend out of the way of the first coil's nut making all 4 easily accessible.
Now remove the spark plug wires from the coils, easiest way to do this is (standing over the fender) rock them towards the front and back of the car, then with your hand on the boot using one finger grab the lip of the boot and try peeling it up while lifting the boot, this is to break the seal between the rubber and the coil (due to the heat they become semi bonded)
After that use a 1/4" ratchet with a decent size extension (i use an extension that reaches over the hoodline so i dont have to lean over at all, im just lazy) also a 1/4" swivel adapter and 10mm deep socket. May want to have a magnet handy to grab the 4 nuts when you remove them.
Now with the nuts removed you should be able to pivot the bolt hole portion of the coil up and over the stud, there will be enough slack in the wiring to pull it slightly towards you and make disconnecting the connector easier.
To reassemble proceed in reverse order.
Thats how i do it daily, makes changing all 4 coils about a 5-10 minute affair.
also remember the coils, from firewall forward, are t2,l2,t1,l1.
kevin.
03-22-2009, 07:05 PM
#10
Unbalanced & Unmedicated
I installed the BHR set a couple weeks ago. I found it much easier to access the plugs and get a solid connection with the new wires by jacking up the drivers side. No need to remove the tire. Just high enough to slide under and reach up. Far easier than trying to reach down. . .
03-23-2009, 12:06 AM
#12
Certified Mazda Tech
people at work say this about me all the time cause im too lazy to pull the tire and so i just squeeze in with a nice extension.
as for if you lose 1 of the 4 nuts. You can use a generic one but i'd try to go with the same style.
i think it's 6x1.00 with a 10mm flanged head. Then non-flange ones will work but will probably loosen up over time.
kevin.
as for if you lose 1 of the 4 nuts. You can use a generic one but i'd try to go with the same style.
i think it's 6x1.00 with a 10mm flanged head. Then non-flange ones will work but will probably loosen up over time.
kevin.
I get to clean my rim and brakes out.
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Shmartyy (12-08-2021)
03-27-2009, 11:42 AM
#15
Certified Mazda Tech
03-31-2009, 06:48 PM
#17
I just pulled mine in a few minutes, really easy.
DO NOT PULL THE AIR BOX OUT COMPLETLY - I didn't pull the airbox completely out all you have to do is pull it out from the bottom so you can till it up to get the accordion tube off. I did remove the strut tower bar, considered that took about 2 seconds and it made life easier.
Also on the metal piece that the coils sit on, the 4 coils are labeled. T1, L1, T2, L2. Thats not the official order, i forget right now. But mine were rusted, so i took a dremal with a wire brush and the whole panel is nice and shiny and when i removed the rust i found the labels makes it real easy considering the spark plug holes are also labeled.
Another thing, what the heck is that black box on the side for, there is nothing attached to it, its just an empty box? Some type of pressure thing or something?
DO NOT PULL THE AIR BOX OUT COMPLETLY - I didn't pull the airbox completely out all you have to do is pull it out from the bottom so you can till it up to get the accordion tube off. I did remove the strut tower bar, considered that took about 2 seconds and it made life easier.
Also on the metal piece that the coils sit on, the 4 coils are labeled. T1, L1, T2, L2. Thats not the official order, i forget right now. But mine were rusted, so i took a dremal with a wire brush and the whole panel is nice and shiny and when i removed the rust i found the labels makes it real easy considering the spark plug holes are also labeled.
Another thing, what the heck is that black box on the side for, there is nothing attached to it, its just an empty box? Some type of pressure thing or something?
Last edited by bsteimel; 03-31-2009 at 06:50 PM.
04-04-2009, 08:02 PM
#18
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just did my plugs, wires and coils. Great posts to save me lots of time with trial and error! I did not remove the airbox as I agree it's a real pain. Might have made it a little easier but not much. The cable assemblies were not real easy to remove from my coils - tuff to reach and unclip but eventually got them off. I did remove the drivers side front wheel as in a related DIY. Probably saved $600 based on dealer quote two weeks ago at my 60K inspection. Brakes are next - also look pretty easy.
04-04-2009, 11:37 PM
#19
Certified Mazda Tech
just did my plugs, wires and coils. Great posts to save me lots of time with trial and error! I did not remove the airbox as I agree it's a real pain. Might have made it a little easier but not much. The cable assemblies were not real easy to remove from my coils - tuff to reach and unclip but eventually got them off. I did remove the drivers side front wheel as in a related DIY. Probably saved $600 based on dealer quote two weeks ago at my 60K inspection. Brakes are next - also look pretty easy.
kevin.
04-20-2009, 08:11 PM
#22
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does it matter what order the coils are put in? i've got new factory coils and they are labled
1-1, 1-2, 1-3, 1-4 which leads me to believe thats the order number they need to be put in.
please correct me if i'm wrong. my baby won't start!=0(
1-1, 1-2, 1-3, 1-4 which leads me to believe thats the order number they need to be put in.
please correct me if i'm wrong. my baby won't start!=0(
04-20-2009, 08:30 PM
#23
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Another question, my AP should be arriving any day now...to get the maximum BANG! for my bucks, should I go ahead and replace the plugs and coils and then do the AP thing? My car has about 17500 or so now. It's an '06.
04-30-2009, 09:36 PM
#24
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i did some asking around before doing the job, and from what i have been told, the labeling dosnt matter.
