First Gen mazda 3 with 2.3l recommended service approaching 160k km

Mar 20, 2008
Thanks for all the help! I need help with the coil on boots, there old and might as well replace them with the plugs. I know spark plugs are finicky and u want to run oem or something similar to oem so ill be running the oem plugs, any help on which one of these coil on boots would be best for my mazda or does it not matter? im thinking between the ngk, denso, and the delco. seems odd to me that the ngk is one of the lower priced ones, i thought ngk was basically oem and is usually expensive?


Get NGK or Denso


Thread starter
Nov 19, 2020
Not sure what plug Mazda uses from the factory, but Ford's factory spark plug for their variant of the 2.3L is the Motorcraft SP530 which is a rebranded NGK 90607.

thanks! i believe its the NGK 3811 ILTR5A-13G

but all i can find on rock auto is NGK 90083 LTR5BI-13
Dec 28, 2014
With any car as I approach 100,000 miles here’s what I do...

air filter
cabin filter
and transmission service (probably the second time you’ve had it done by now)
Differential/transfer case (if you have one, which you don’t on the Mazda)

serpentine belt

What I wouldn’t do is...
O2 sensors
water pump, thermostat, hoses.
Alternator and a few other things you mentioned. It’s just not practical or necessary. First off, you don’t just replace things that aren’t broken. Second, when you replace things like this you could break other things (think surgery, things can and will go wrong, best not to do it if you don’t have to open someone up). Third, you have OE parts in there right now - aftermarket parts might nit be as good (even new) as the OE parts you’ll pulling out of the car. And if you use OE parts you’ll be paying for it, and then some, you won’t be saving yourself anything in “preventive maintenance“.

Just my professional opinion.

PS- If the engine has a timing belt, change it and replace the water pump, tensioner and pulleys.
Jan 21, 2011
Since you don't know the maintenance history and it's near 100k miles, I would change all the fluids including transmission, differential... everything.

Here's a basic list of 100k miles maintenance:
Change spark plugs
Change engine oil & filter
Clean TB & MAF
Change fuel filter if it has one
Change coolant, no flush needed unless it has engine cooling or interior heating issues
Change thermostat
Change accessory belt
Inspect engine air filter, cabin air filter, hoses, exhaust, suspension, brakes, drivetrain, repair/replace as needed
Good luck with the new ride!


Apr 28, 2005
Vancouver BC
Hello all, new member here, I just recently picked up a 2006 Mazda 3 with auto trans and 2.3L engine. I don't know much about the maintenance info on it but want to start doing some preventative maintenance pretty soon. Sorry I am not a mechanic so I will try my best. I checked the fluids in the car and as far as I can tell and based on the service records I could find, the following are all new: trans fluid, power steering fluid, brake fluid, brakes, engine oil and filter, and air filter. so on a fluid side of things I am already on a good start. seems like mazda forums are mostly dead for the gen 1, so I thought I would ask what I should do for maintenance for my gen 1 mazda 3 with the 2.3L. Here is a list of things, let me know which ones I should do, and which I should skip. Car is almost at 150,000 km which is almost 100k miles

1. spark plugs - will have to see if they have been changed before I do them
2. belts
3. Water pump and thermostat - as far as I read it seems like most people only do the water pump when it starts to leak, but I assume thermostat is preventative maint?
4. Alternator - is this done when it dies or is it kinda a preventative maintenance
5. O2 sensors ?
6. suspension wise car seems fine but will check the shocks and etc
7. Clean maf/throttle body
8. fuel filter?
9. Fresh coolant? I assume just drain the rad and fill it to refresh the fluid?

please let me know which of the following you would for sure do and which you would wait on, also feel free to ad on if i am missing anything

**just added pic of the owners manual, i know some people just follow the owners manual and some dont so i wanted some advice cuz sometimes the owners manual can be overkill**

thank you all so much!
Plugs are cheap, I'd do them. Coolant change is a good idea, and look for cracks on the serpentine belt and change if noticeable.

I'd change the trans fluid if there's no history of it. If your cabin starts to smell musty, cabin filter could be the culprit (note it's not an easy job to replace).
Aug 14, 2013
I would add inspecting cv joint boots for leaks, cracks, splits or dry rot, as well as inspecting fuel and brake lines for corrosion. Check the date code on your battery to see how old it is, if original I would replace as it would now be over 14 years old.