2012 Mazda 3 2.5S Maintenance/Build Thread

I tackled the A/C condenser and radiator job over the weekend. My apologies for not taking more pics, as I was fighting the rain and needed to get this done.

First, I consulted an online service manual and a Youtube video of some Russian guys doing this job. Both of them said that you have to remove the front bumper, and to do that, you have to remove the wheels. The Russian dudes also removed the hood. So, that led to this:

Other than removing most of the front end, first step was to disconnect the battery. To get to the radiator and condenser, you have to remove the undertrays, remove the airbox, unlock the radiator from the core support with the two lock mechanisms on the support, drain the radiator, disconnect the upper, lower, and overflow hoses from the radiator, disconnect the high and low lines from the condenser, unplug the fan and coolant temp sensor plugs, and remove the fan. While all the stuff I saw had you remove everything from the top, I found it far easier to go from the bottom. In fact, I could have foregone removing the bumper, wheels, and hood! D'OH!

Oh, and yeah, the condenser was DONE.

To be honest, I have no idea how it lasted as long as it did.

Once everything was out of the way, it was easy to slide everything out the bottom.  I transferred the coolant temp sensor to the new radiator, connected the condenser to the radiator, and up it went. Putting it all back together was much easier.

After filling the radiator and checking for leaks, I went to add refrigerant. I had borrowed a set of manifold gauges and had the correct amount of R134A and some compressor oil to add to the system. But for some reason, the system wasn't sucking in the refrigerant as it should; it either leaked out the lines or didn't go into the system. It was getting late in the day, and the parts store up the street didn't have a rental vacuum pump, so I decided at this point to "ghetto charge" it. I grabbed one of those lines that come on the cans you see at parts stores that I had in the garage and shoved in some refrigerant and oil. To my surprise, it worked! Compressor kicked on and it has been holding a charge for a couple of days.

That said, that's not the right way to charge an A/C system. Moisture kills A/C systems, so I ponied up and bought a pump at the Hammer Store yesterday:

I'll be revisiting this next weekend. I also figure that I want to put A/C back in my Trans Am and add it to my Power Wagon at some point, so this will come in handy down the road.

Quick update on the ol' Mazda:

I've only put 5,000 miles total on it so far this year since I've been taking the train to work instead of driving; it just hit 178k this week. The A/C repair held, and it has been working great throughout the summer. The exhaust has gotten really loud lately, but the spot in the front manifold/cat pipe wasn't the culprit; the noise was further down. I crawled underneath to take a look:

That's one of the pinholes I saw, but that whole area seems to be leaking. This is in the mid-pipe, which on my car, is welded to the rear catalytic converter pipe, so I have to replace both. The front manifold/cat pipe seems ok, and the rear muffler assembly seems fine, so I'll order this up and replace it soon.

On 10/1/2019, it will mark 8 years of ownership with this Mazda 3. I'm truly in uncharted territory with this thing; I've never had a daily driver this long!

I've put about 180k on it in those 8 years, and it's still chugging along. For the last few years, I've had to buy it some "anniversary gifts". This year's apparently the Exhaust, Engine Mount, and Shift Knob Anniversary.
The rear cat pipe started rotting right after the resonator (see the above post), and it's one giant piece, so I have to buy two aftermarket pipes to replace it all. You've seen me replace the transmission mount twice in this thread, and I did replace the bottom mount once with a solid mount, but that was short lived and the stock one went back in years ago and I never changed the hydraulic mount. Lots of stuff up there is clunking away, and since all of the front suspension is new, I'm hoping the new mounts help. And while I love the stock shift knob, it's worn and starting to fall apart, so I picked up a delrin knob to replace it instead of dropping $100+ on a factory one.

I'll post updates after everything gets installed.

You are much more willing to tackle big jobs than I am. But, congrats on keeping it going!

I'm only just over 81,000 miles on mine. Rear brakes are still going; not sure why they squeak when wet, but there's plenty of pad so whatever. My trans make a click/clunk sound when I put it in gear (reverse or drive), and the AC smells horrible when it's on max/recirc. The cabin air filter was replaced less than a year ago so not sure about that either.

In reply to slowride :

On the trans noise, I can almost guarantee that you need a transmission mount. They all do right around your mileage. They are not that bad to do, but require removal of the battery, battery box, and air cleaner. My write-up a few pages back should be close enough for an automatic car.

On the AC smell, unless somethig crawled into a duct and died, maybe try one of those Meguair's air freshener bombs?

You set that thing off with the A/C and HVAC at full blast, and it gets into the vents and all that.

I figured it was probably the trans mount.

The bomb seems like a good thing to try at least, I forgot they made those. Thanks!

In reply to slowride :

Yeah, did that a few times with the wife's old cars. They work pretty well, at least for a while.

Also, don't sit in the car when it's doing its thing unless you want your insides to have that fresh new car scent. Also, it might kill you, so probably not the best idea!

I tackled the engine mounts today. All in all, not a bad job. Basically, get the car in the air, remove the undertray, support the engine with a floor jack, and replace them! The passenger side mount was a little more involved, but it only took meabout an hour to do it all. 

After removing the coolant reservoir, 4 17mm nuts and bolts come off and this pops out. You only need to replace the insert on the 2010+ cars. 

After 179k miles, this one was smoked. 

The insert is clamped onto the mount by these bendy tabs. Unbend the old ones and pull it out. 

Then, you pop the insert in and bend the tabs to mount it and bolt it back in. Easy peasy. 

Even easier is the lower pitch mount. A 17mm and 19mm are needed here. There's a through-bolt and a center bolt you undo with the 17mm, and there are three 19mm bolts that ghold an aluminum arm on that connects the mount to the engine. Undo all of that, slide the new one in, and tighten it all back up. 

I also replaced the broken and worn stock shift knob with this Torque Solutions delrin teardrop knob. It fit perfectly and was under $25, and I love it. It's a lot lighter than the stock knob, which makes the shifter feel more direct and "snickety", if that's even a way to describe it. It made the perfect stock shifter even more perfect, and I should have gotten this thing years ago. 

Next up: replacing most of the exhaust. That's not gonna be fun. 

Whelp... It's "anniversary week", so I figured I'd install the exhaust parts I bought, along with performing an oil change. This meme pretty much sums up my day today:

Before I got started, I needed to remove two crossmembers to access everything. Those came off easy enough. I was able to confirm where the exhaust leak was, and it wasn't where I originally thought.

Where the heat shield meets the pipe, there was this hole. The rest of the pipe looked like it was going to crumble apart any day now, so I'm happy I replaced it.

The stock cat/resonator and midpipe are one piece, so I had to order two parts and use an adaptor to step it down from 2.5" to 2". Here's the old one next to the new assembly:

The fun part was that I needed to remove the muffler assembly because the nuts and bolts changed shape due to rust and I needed to drill what was left of the old bolts out of the flange. I had to cut the old midpipe with a sawzall. All in all, that went smoothly.

I was able to get everything up and in, and the leaks were gone!

I tried to get those shipping labels off, but they wouldn't budge, so up it went.

BONUS BREAKAGE!
 

When I jacked the car up in the air, I heard a weird suction sound and then heard some sort of fluid piddling all over the driveway. Turns out it's one of the shocks I replaced last year. They might have 10,000 miles on them, but yeah, this one is smoked. I'll have to replace these soon, and this time I'll replace the mounts, too.

With everything back together and the oil change done, I gave it a spa treatment for it's "anniversary". I've barely washed it in the past year, let alone went anywhere near it with detailing products. I hit it with some Meguiar's Mirror Glaze cleaner and waxed with some Mother's synthetic wax using my Hammer Freight random orbit polisher. The old workhorse cleans up well, I'd say!

After the rear shocks get replaced (again), this will hopefully be good for a while.

New KYB Gas-A-Just rear shocks and mounts have been ordered; I'll toss those in when they show up.

A couple of other things I forgot to mention in my previous post:

-For the first time ever, I noticed that the car used some oil when I did the oil change. When I was racking up 26k miles per year, I was changing oil at 7500 mile intervals. Since my job location changed and I now drive a lot less, I reduced the intervals to 5000 miles. The car used about a quart between now and the last change, which might be attributed to it not being changed in a while (time-wise) and the shorter, in-town trips. It takes 0w20 full synthetic, BTW. I'll keep an eye on this in the future.

-When I was bolting on one of the crossmembers that go under the exhaust, one of the nuts stripped out and the welds that held it in broke. I had to cut the bolt out to prevent it from rattling around in the subframe, and I tightened everything else up and hoped for the best. Unfortunately, it's smacking the floor and banging around going over bumps, so I need to figure out how to bolt it back on or at least lessen the noise. I was thinking a drywall toggle bolt or something similar may do the trick. I can't easily get another nut in there, and there's no way to tack one in place without cutting a hole in the floor pan, so I'll have to figure something out.

Aside from the extra noise from the crossmember, the car is so much quieter now and much more pleasant to drive. I think I'll keep it for a while longer.

Spent tonight after work trying to fix the new rattle. I was able to bolt up the crossmember with a fender washer, but the rattle remains. I checked another crossmember that also runs under the exhaust, and it's close to the resonator, which is a different shape than the OEM one. I clearanced it a bit, and it seems like the rattle is less, but still there. I might just remove it altogether next time I have the chance. 

Even though it's currently starting to "Nor'easter" out, and it's dark out, I had enough of the clunking exhaust. Here's the culprit:

This underbody brace fits fine with the stock exhaust, but since the new one has a barrel resonator instead of a tapered one, it smacks the center of this brace over bumps and under throttle. I'll have to trim some of that center section out and bolt it back on sometime soon, but for now, no more clunks!

So yeah, if you ever have to replace the center section of your exhaust on a 2010-13 Mazda 3, and you buy the aftermarket-style pipe with a barrel resonator, plan on removing and modifying this brace.

Did the rear shocks yesterday. Both of the Monroe OESpectrum shocks were blown to hell with just 10K miles on them. That is flat-out unacceptable. The good news is that the KYB Gas-A-Just shocks I put in made things better. Car doesn't have that uneasy feel from the rear that it did before, and they feel great over the bumps and in the corners.

With the new exhaust and the recent suspension work, the car is a joy to drive again, even with 180K on the clock.

Next up: getting it ready for winter.

I've been driving the car as normal since the last update, and swapped on the winter wheels and tires a few weeks back, putting the car in Winter Mode. Since doing so, I've noticed that the tires are WAY louder than they were last year, but they don't show any uneven wear. Puzzling. It also feels a little uneasy on the highway at higher speeds.

Also, since it's gotten colder, I've noticed that the telltale signs of the transmission mount failing have started to happen. It's clunking going from reverse to 1st gear, and creaking at low speeds with some extra vibration. I was hoping to hold out until I could do the clutch, but I may have to replace the mount again soon. This will be the 3rd time I've replaced that mount.

Speaking of the clutch, I plan on replacing it at a friend's place who has a lift. There aren't many instructions/walkthroughs out there on doing one yourself, so it should be interesting. I want to do the clutch and a flywheel, since resurfacing the stock one is going to be a multi-day affair and will tie up his lift for a while. That's where things get weird. One of the only aftermarket listings for a flywheel is LUK par number LFW359. There are zero pics of it on the internet, and LUK's online catalog is a convoluted mess and mostly in German. It ranges from $72 on RockAuto to $400+ elsewhere. Might have to take a shot in the dark and order one when it becomes time.

The clutch on these is pretty straightforward FWD stuff, nothing memorable about the job except separating the ball joint from knuckle can be a bit of a pain.   Use Redline MT90 in the trans. 

In reply to Sonic :

Yeah, I need a fluid change to the list, thanks for the reminder! It hasn't been changed in a LONG time. I am using MT90 now, and it saved the transmission! Early on, it would crunch the 1-2 shift, but that went away with the fluid change.

Hi Tony,

I came across your thread while looking for info on the "minor evap leak" CEL (impossible to find info on this like you said!). I've replaced the easy purge valve under the hood but it hasn't cured it. I think I will check over all the lines and then replace the rear valve next but I'm not looking forward to digging into my 10 year old New England suspension. The dealer by me is a bunch of crooks so I refuse to do that but I have emissions coming up in May. Did swapping back the OEM gas cap fix your second CEL light?

By the way, great thread! Having a 2010 Mazda 3 with the 2.5L and MT 6 speed since 7 miles on the clock I can say I have replaced just about everything you have up to this point, mileage is currently a touch under 166k. My miles have been more back roads then highway but it has seen its fair share of road trips from Canada (multiple times) all the way down to VA. It still gives me back the same amount of oil I put in at changes and pulls as hard as it ever has. I averaged about 29-30 mpg for the first 5 years but these days I get about 26 in the winter (snow tires and cold starts) and 28 in the summer and this is with minimal highway. I recently took a trip to South Jersey and returned 32 mpg doing 70-75 on the highway with summer tires (it's been a mild winter).

I still love the car as much as the day I bought it. It was one of only two hatchback 3s back in CT in May 2010 with the "sun and sound" package which is all I wanted with the 6 speed MT. 

Other issues I have had that you didn't seem to encounter were an intermittent failing fresh air door mechanism (it will rattle very loudly for 10-15 seconds and then open/close) which I've had for years but doesn't warrant tearing the dash apart to fix. A couple weeks ago the Bose system AMP went bad. The AMP is $850 for a new one but Bose was awesome and covered it, sent me a new one for free and I'm back in business.  My goal is 200k from mine on the stock clutch and engine, both of which seem to be in great condition (knock on wood lol)

My wife had a 2012 3 sedan with the 2.0 Skyactive, we put 145k on it with only oil changes, brakes (once) and tires. We traded that in last year for a CX-5 AWD since we needed more room for our little one. Got her a 2016.5 with 26k on the clock (off lease) and little over a year later we've only had a minor brake light sensor intermitently fail which was fixed under warranty. It's a great car and has the updated 2.5L from my car but in Skyactive trim.  I hope to get many good years out of this Mazda as well.

Sorry for the rambling post! Maybe I will see you at Thompson, I bring my other car out there for SCCA Track nights a couple times of year usually.

In reply to Redwalsh87 :

Glad this thread helped someone, that was the reason why I started it!

Back after I had all the emissions stuff replaced, I was getting that CEL with an aftermarket gas cap from Autozone. I put the stock one back on and it's been fine ever since. I have about 183k on it now, and it's been off for over 20k miles. Your issue is likely that purge valve next to the gas tank. It's DIY-able, but it was winter when it happened to me and the dealer didn't charge too much for the job. You have to remove part of the rear passenger-side suspension to do the job.

My car has two issues right now: a driveline noise and a problem with the braking system.

The driveline noise is likely the transmission mount again. It's the same high pitched NVH vibration under load that it's had before when the mount was smoked. I've replaced the other two mounts recently, but the trans mount has been in there for a couple of years. This time, I'm ordering an OEM mount. I think the aftermarket ones are meant to fit cars with automatic transmissions. They look the same, but they are not. Mazda has revised the mount 4 times since 2010. Hopefully, this will be the last one I have to do. This will be the 3rd one I've done.

The brake issue is really strange. Sometimes, under normal braking conditions, the brake warning light comes on (the same one that comes on when you use the handbrake). I thought it was the handbrake switch, but that works like it should. The fluid is at a normal level, so it's not that. I have no idea what it is. The brakes feel fine, so I'm not sure what else could cause this.

The clutch is likely the next thing to go on mine. It's felt vague lately, but it still holds. I'll see if I can make it to 200K with it!

Oh, and if you are ever attending a Lemons event at Thompson, look for the green and white 1976 280Z. I'm usually hanging with those guys at the August race.

Tonight, I was getting annoyed by that intermittent brake light coming on, so I took a look at the fluid. Last time I looked at it, I saw that the fluid level in the reservoir was fine, so I never thought anything of it. What I never did was actually open the cap. When I did, it was very low. The "level" on the reservoir was more or less a stain from 183k of the level being in the same area.

Huh? Really?

I filled it up, so hopefully that stops. But here's the mystery: where did that fluid go?

One thing I've never done is change the fluid. I know, bad Tony. I've never had fluid just disappear before in a sealed system. I've had levels fluctuate due to pad wear, but these pads should have plenty of life left. The pedal is firm, and the brakes feel fine like they always have, but I'll be looking for leaks soon anyway. Is the clutch related to this in any way?

In reply to Tony Sestito :

I replaced the rear lower mount and the one over the trans around 80k. I still wasn't happy with how it felt (loosy goosy) when shifting so I bought a poly insert for the rear one from Corksport. It was a 2 piece insert that pretty much filled in the empty space between the rubber mount. It definitely made it solid but brought a lot of extra vibration and noise into the car. I compromised and removed one part of the insert leaving the other, has been perfect since as its right in the middle. And I haven't replaced any of the other mounts since. My passenger motor mount is still stock and looks fine, no fluid leak or anything and there is no excessive play.

The brake light issue sounds like it is your fluid. And yes, the reservoir services both the braking system and clutch system. The reservoir kind of "splits" for both but they may as well be together. Sounds like you are losing fluid somewhere. I wonder if your weak clutch is actually due to fluid leaking from the slave cylinder onto the clutch. This just happened to my brother on his 86 C10 pickup. The fluid also drastically goes down when the pads wear down far. If it was never topped off due to the stain making it seem full at the last brake job that would explain that. 

I replaced the fluid in the entire system (brake and clutch) at my last brake job with some good synthetic DOT 3. It didn't look that bad but after 9 years and 140k or so it definitely wasn't as good as new. I would highly recommend you flush both systems and refill to full. Easy job and it might help you notice any leaks.

I haven't been to a Lemons event but it's on my list. I should make an effort to attend this year.

In reply to Redwalsh87 :

Yeah, I'll be bleeding out that old fluid soon. This morning's drive to work was uneventful with no lights, so I'm guessing that the fluid was just that low. I did the brakes about 20k miles ago (around 2 years ago) so they should have plenty of life left. I'm swapping on my regular wheels and tires soon, so I'll check everything for leaks then.

And YES, you want to check out a Lemons event, trust me. It's insanity!

Speaking of Mazda 3S's with the 2.5i, namely mine, she has 218k mile's on the clock. Next oil change is at 221k....

In reply to Bill Mesker :

Nicely done! That's a lot of miles!

In reply to Bill Mesker :

That's a lot of miles, hoping I can get there too. I've been using Mobil 1 since new and I typically go 6k between changes. Have you always changed it every 3k?

When I was driving a lot more than I do now (25k mi/year), I was changing oil every 7500 miles, mostly on the highway. I didn't burn/lose a drop. After my job location changed and I started taking the train (train station is 2.5mi from the house, 10k mi/year now) the first oil change I did saw the first oil consumption ever. I have switched to every 5k now, and it's been fine. 3k intervals with full synthetic is unnecessary. 

I've been using either Mobil 1 or Castrol Edge 0W20 since the beginning. For filters, I typically use Purolator or Motorcraft, since it's basically a Ford engine anyway. Both have been great.