Walkthru on coil replacement for 2002-

[f1drivr]

I finally got hit by a coil problem. 97,500 miles on my 2004.

Wed, the CEL came on, DW freaked out. Met her at lunch and drove to Autozone. Code was misfire on #6 cylinder. I swapped the coil to #5 to see if only the coil was the problem. The car drove ok, no noticeable misfire, just sluggish. Then Saturday, we decided to head out on a road trip (100 miles). I know, you think why try it, well... I wanted to give the car a long workout to trip the CEL. Also, the weather report said possible hail and I would rather my older car get hit. I have sincere fear of hail as I have had 2 new cars hit with significant cosmetic damage.

CEL comes on, return home after being out about 30 miles. Autozone scanner shows misfire on #5. Buy the $65 coil, swap out in 5 minutes. Runs fine.

Now I wait for another CEL, hoping it is the front cylinder bank. If it is the rear, I will replace all of them.

[truecrimson]

Thank you bubba and everyone on this forum. Replaced the plugs and coils last weekend and the '03 MPV is running great. Just tested it thoroughly on a fairly long road trip with some mountain terrain.

I did have one minor problem I will share with everyone so you guys can be careful and hopefully you won't have the same issue. Apparently I had defective or heat-weakened intake manifold bolts. Two of them snapped before I got them in the lower range of the torque specifications. I thought my torque wrench might not be calibrated properly, but the second bolt snapped with a different torque wrench. Luckily the design of the bolt prevents it from shearing completely and you can remove it.

$2.00 Per bolt at the local Mazda dealer. New bolts were able to be torqued to the proper specifications without any difficulty.

[ZoomTroop]

Hey Bubba, thanks very much for posting this. I just did this to replace #3 coil and you made it very easy! The only thing I did different was to just unbolt the throttle body rather than disconnect the cooling lines. Total time was only 2 hours and that was milking the time because it was nice to get back under the hood again. If I was in a hurry it could probably only be a 45 minute job. When I got done I went ahead and followed your transmission flush tutorial so the DW's ride is good to go.

BTW, coil #5 was replaced under warranty last year, so I am expecting to do this again in the future. I debated doing 1,2 &3 all at the same time, but you made it so easy I have decided to wait and do 1&2 when one of them fails.

[cossie1600]

Why would you go through all the work to get to the rear banks and only do one coil? Do all 3, save the 2 good coils on the front, it will blow out soon anyway.

[dj_h8]

Another "thank you" to bubba and the folks who have posted other tips and suggestions about replacing coils!

I first replaced all 6 plugs on my '03 MPV and it didn't improve my "random" misfire problem (P0300.) After getting code P0303, I tore it apart again and replaced all 3 rear coils. Voila! Engine runs smoothly again! I should have done this the first time I had it apart.

Might I add that I am no gear-head and this was my first "major" repair under the hood. It may have taken me a little longer than some of the pros (about 4 hours of careful work) but the pics and instructions guided me through it beautifully!!

Now I'm going to try the non-fouler trick to "fix" a P0421 code. I know for a fact that my rear cat. is shot so I figure I need to make the mod. downstream of it. I'm a little confused about the discussion (on other threads) of installing this on the O2 sensor nearest the firewall for this code. Can anyone clarify the location of the installation on the giant picture in this thread:

http://forum.mpvclub.com/viewtopic.php?t=22162&highlight=p0421

[expy98]

Just did the procedure this past weekend. I'd printed the walkthru and he Powerpoint docs and they were invaluable, takes out all the guesswork.

There were only a couple of minor details as mine is a 2005 but the bulk of the docs are spot on.

Mine had P0301 which is cyl 1 misfire. I decided to swap all the front oils to the back and new Autolite Double Platinums ($1.50 rebate per plug good til end of Nov) and inspect the PCV hose.

The stock coils are all "AB" version, the stock plugs are Motorcraft single platinum. All the plugs looked good except for plug 1 which was pretty wet w/ fresh-looking oil on the threads but the tip was dry and almost the same coloration as the other plugs. The PCV hose is still solid esp at the elbow (<35K miles).

So far, running tip top again and coil 1 seems to be happy in cyl 5 but if it acts up I can easily replace it. Been averaging only 15mpg so now anxious to see the improvements.

Took me 3 hours taking my time. I think it can be done in 1 to 1.5 hrs once you've done it before. The most difficult part for me is unplugging all those electrical connectors; they don't always come out easily, I suppose I have weak thumbs. I'm cheap so I wouldn't hesitate to change out just one coil as it's easy enuf to do while doing an oil change and let the oil drain completely.

While there, installed a new Wix air filter and cleaned out the cabin filter. Unfor mine is a 2-pc filter and the filtering element on it is rediculously thin, I plan to use a HEPA filter sheet (that I got from a friend who works in biomed) to replace the cabin filter elements.

Next up, Hawk HPS pads.

Kudos to the contributors and the forums. Is there a way to send beer money to help one temporary forget the time/money to maintain this site?

[savedsol]

Unfortunately I haven't seen Hawk pads for the MPV. Got Akebono ceramics off Amazon instead and they're great.

Back to the topic at hand, I replaced the plugs in March of this year and ever since (though constantly growing worse) I get a fuel smell when idling and and the HVAC on fresh air (heat or cold doesn't matter). The smell is coming from the passenger side of the engine right around where the fuel rail is. I look constantly and never see any actual fuel or wetness and our mileage is still great. Any clues? I'd hate to pay a fortune just to have it "looked at".

I can tell you the rubber strip at the firewall/hood is collapsed and useless. I've just but a bit of plastic hose down the middle of it so hopefully that and recirc will help til this is fixed.

[esmithiii]

Guys (and gals)-

Is there a diagnostics tool I can buy to reset the CEL, and to tell me which ignition coil(s) I should replace?

Also, can someone point me in the right direction on which brand/manufacturer replacement coil I should buy?

I have a '04 MPV.

Thanks in advance!

[subearu]

Mazda has a special tool to detect misfires and pinpoint the coil with a problem, but in general, the CEL doesn't always light up on a misfire, seems to have be major in order to turn it on. You may find a code stored though, indicating a misfire on a cylinder though.

You can go to your favorite auto parts store and buy a OBDII code reader. Personally, I have the ScanGaugeII. AutoZone use to loan out their reader, but it seems some folks have found they don't do that anymore.

If you don't have codes stored, you may have to try isolating the suspect coil on your own by moving them from one plug to another. Typically the ones in back go first, but the up front ones can cause problems too.

This very thread has the part #'s of the good replacements and their equivalents.

-Brian

[kroland]

At what mileage do you think this will be needed?

[burleymike]

Mine has just under 90,000 miles and they just started acting up. It seems to happen in damp climates more than in dry climates and when the weather is cold.

For about a week before a coil failed my wife said when sitting at a light or at a drive thru she felt a bump. It was like one of the kids moving around in the back. The day she felt several of the bumps the kids were sleeping.

I also felt it a couple times. I had the defroster on so I hoped it was the A/C compressor cycling but I knew it felt more like a slight misfire. I never got a CEL until it was a huge misfire.

As subearu stated Mazda dealers have a scan tool that will detect even the smallest misfires.

[keoni50]

Huge thanks for posting the walk through! I have a 2004 and the first time I got a CEL P0301 it was the number 5 cylinder and that was a easy job! I now have another P0301 code but it's the number 1 cylinder. Prior to the CEL I had the PCV hose changed at a Stealer for @199.00. I tried and tried to remove the hose clip with the special tool but could not do it!. Now my question is, does anyone know how much a Stealer would cost to replace the 1-2-3 coil packs? I do have lots of time on my hands because I'm out of work but I'm concerned I'll have problems getting the PCV hose off, just like I had the last time. (Can I leave it attached on the intake and move the intake aside??)

One more thing, you really have to appreciate the enormous work that goes in to a forum such as this! I'm a Site Admin (learning) at another car forum and can't believe ALL the work that goes into a forum! Hats off you all you Admins and moderators here at MPVClub.com!

Please reply ASAP as I need to get it back on the road.

Thank you!

Keoni50

[cheapdad00]

Special thanks to the instructions here as well as the powerpoint on removing the intake manifold. I replaced my bank1 sensor 1 O2 sensor (along with spark plugs, etc.) two weeks ago and this thread was invaluable.

[monomer]

Bubba... A really big thanks for your excellent tutorial... and I do mean excellent! I registered on this forum just to tell you how thankful I am. You saved me some big $$$$. Last summer my wife got a check engine light and we took it to a local mechanic. He charged us $280 to replace a coil and spark plug. It really bothered me that we should have had to replace an ignition coil and plug with only 60,000 miles on the car. Then in December... again with the check engine light, however this time I hit the Internet and after a quick search found out just how COMMON this problem is on the MPVs. I had the code read and it turned out it was #5 (and last summer it was #6 after I'd checked the recept from the garage). So I decided to replace all of them. I bought all six coils for $180 (excellent quality and made in Japan) and a good set of irridium plugs for $42 for a grand total of $222. It was a cold day in December when I went to do the job and chickened out after doing just the front bank (it took all of 12-minutes to do the whole front bank from start to finish... it was so rediculously easy to do and it was at that point I realized just how badly I had gotten ripped off by the garage that charged me $180 in labor! and $100 for parts... I can just imagine what they would have wanted for labor if it was in the rear bank). Well, rubber hoses don't really like to cooperate in 20F weather and my hands weren't wanting to cooperate either.... so after doing the front bank I decide to wait for more pleasant weather before tackling the rear bank. Well, today was just such a day... 80F+ and sunny. Referring to your excellent tutorial I was able to finish the job in under 2 hours. The biggest problems being having to retrieve a dropped screw, one nut and that EGR thin metal gasket (which as it turns out is non-magnetic unfortunately)... otherwise it would have taken probably less than a hour. No matter, its done and the MPV starts-up and runs perfectly and I now have the peace of mind that the coils won't give out for at least another 60,000 miles. And I did it all for less than what that garage charged to do just a single coil/plug in the front bank. Bubba, thanks for saving me a lot of money, you da' man!

[davey]

i was a victim of the dropped egr gasket too.
careful on that, it is paper thin and hard to find once you drop it!

i did find that you could rotate that intake once all the bolts are out, making it even faster.

I just wish the dealers would cover a free test to determine which coil is needed. that's the least they could do for this shotty design