#4 spark plug fouled
 

I've seen a few other posts like this but none recently. I have a 2003 P5 with 26000 miles on it (no mods) and this is the 3rd time I've had this problem. Around 12-15k miles, the car started sputtering and stalling. The dealership replaced the #4 spark plug because it was fouled. A couple of weeks ago, the same thing happened and the fix action was the same. 3 days after it was fixed, it happened again. The dealership hasn't had the chance to look at it yet (although they've had it since friday), but they called me a said that it may be because of carbon build up. Does that sound logical? The second time I had it in, the mechanic called me and asked me if I had taken the spark plug out and dropped it??? I read in another thread that the piston was hitting the spark plug and they put in new heads. Anyone else had or heard of anything like this??
If they don't fix it this time, I'm planning on pursuing the lemon law.
Thanks

Take a look at your #4 fuel injector and also the coil that fires the #4 plug. I doubt it's the head. If the dealer keeps replacing the same plug, then it's not the plug that is the problem. After all, what are the chances of getting several damaged ones in a row?
Plug issues are usually the symptom of another problem. Often, those other problems are related to other ignition components or fuel injection.

If the coil is the problem, try swapping it around. The #4 coil on my P5 is paired with another cylinder. One side of the coil fires directly into the cylinder (negative polarity side), and the other (positive polarity) side of the coil fires its waste spark into the other via an attached cable. Both spark events per coil take place at the same time because inside of each coil pack there is only one primary and one secondary winding. If you swap your coil around between the paired cylinders, and the misfire code repeats for the #2 cylinder, then you know it is the coil pack that is the problem.

Injectors are easily removed and replaced as well. I would simply replace the #4 injector, if the coil pack check I noted above does not provide any clues.

dealership called me today and told me that a screw may be hitting the spark plug so they are ordering a new intake. there goes my lemon law claim, but at least my car should be fixed.

Your dealership is on crack.

^ agreed^ What is that for an explanation?! Can you see the piston once the head is off? I would want to!

Something veeeerrry feeshy goin' on here....

I've had multiple problems with this dealer and will probably never buy another car that requires service from them. they've forgot to tighten my drain plug after changing my oil TWICE now. I have two nice stains on my garage floor. I've complained to mazda about them through email and a letter but they just say "thanks for the feedback".

how do you forget to tighten the oil pan drain plug?

Your dealer isn't Kerry Mazda in Florence KY is it? If so I can see why you are having problems. Those clowns didn't tighten my oil filter properly when they did the initial service. I had some other issues with them, needless to say I won't be back there.

You got it. I will never buy another vehicle that requires me to use their service department. They are by far the worst dealership that I've ever dealt with (sales dept. and service dept.)

Don't know how far you are south of the Ohio border, but you might try Kings Mazda up I-71. My brother took his Miata there after the clowns at Kerry couldn't fix his top leak problem, and they took care of it first try.

Oh, and dudeondacouch, these are the same people who didn't replace my A/C charge connection protection caps after fixing the leak it had when I bought it, so that should explain how they could neglect to tighten the oil drain plug. Can you say MORONS? Sure you can, I have!!