A $500 repair bill to basically replace some spark plugs has pissed me off, not that there's much I can do about it now. Feel free to call me a dumbass all you want, I just needed my car back to operating condition as soon as possible:

So after about 48,000 miles on my '05 RX-8 (MT) in Michigan, I finally ran into a situation where it just wouldn't start in my driveway. For the previous 4 years I've had no problems besides one dead battery and some regular dealership warranty/TSB work.

Apparently I'd neglected my spark plugs so much that they turned into a goopy, fouled mess, and my car decided it just wouldn't fire up when I asked it to. I had it towed to the nearest local reputable auto shop (instead of the dealership, which may have actually been cheaper) that did 3 hours of diagnosis & labor at ~$100/hr, plus $35/plug for parts costs, plus injecting some oil into the rotor housings to get compression working again. At least they threw in a "complimentary" car wash.

Should I just be thankful that I've haven't had to pay for any other service costs besides tires & fluid changes & air filters for the past 4 years? $500 spread over 4 years is pretty cheap considering the other horror stories I've heard, but it still kinda hurts when paid for all at once.

And of course the big question is what should I put next on my list of preventative maintenance? I know I need to replace a battery before the cold part of the winter hits, and I've already got solid winter tires. Is there any need to worry about fuel pumps or ignition coils until they actually go bad if they've been verified as "ok"?

 

look at coils too. coils need to be changed every 60k miles for preventive maintenance, plugs are every 30k miles.
other than that I cant think of anything apart from transmission and diff fluid if you want to change them.

 

I believe I had my plugs checked around 30k and the dealership said they were "good enough" at the time, so I said just go ahead and leave 'em in after they gave them a little brushing off. Obviously some frequent cold shut-offs (with my usual 3k rpm revving procedure) hasn't helped matters. I'll plan on getting the coils replaced by the end of the winter then as well. I've also considered changing out the shocks & struts for something a little more high-performance since the handling isn't quite as good as I would like it right now either!

 

Although I do not subscribe to the preventive coil replacement school, letting your plugs foul up can cause the coils to overheat because they can't discharge through the plugs. I would check the coils, and potentially the wires as well. I assume that there are no codes.

 

No CEL visible by me, and the shop checked the fuel pump and coils before moving on to plugs, so I assume there were no simple codes to find.

Can anyone recommend what an average coil replacement should cost through a reputable shop and/or dealership? Is this something that is do-able on a weekend by the average car owner with some moderate non-rotary repair experience?

 

it is an easy DIY. you will need to remove your intake to get to them.

 

Just to be clear, he means the air box where the air filter is, not anything weird. Check the DIY section of the forum, I am pretty sure that this is in there, but yeah, it is really easy. Just make sure that you clearly label the plug wires and replace them one by one onto the new coils. You cross those wires, and you will have problems.

 

There is no guarantee that the coils are your problem though, it is just a likely place to look.

 

Oh I understand, everything seems to be running normally now (and better than before actually, given the condition of the plugs). I was just wondering what else I should be paying attention to so I don't get stranded again!

 

Make sure your battery is fully charged and that your PCM has the latest flash from the Mazda dealer to help prevent fuel flooding in the future.

Paul.

 

Dead/dying battery or bad starter. I would most likely think one of those is the culprit. I just had the same problem and it was my battery.

 

A simple visit to our DIY section at this site would be the next thing I would do. Read up on DIY that our fellow mates took the time to make. You would learn to save money, basic maintence and you will become wise like baby jesus. .

As for what I would change first is the Battery (since its cheaper) then replace the coils and wires.