Dead At 30K Miles!? Mazda Skyactiv-G 2.5 CX30 Core / Blown Engine Teardown

I finally get to learn what Sky Active really means! It’s been a myth amongst us for years 🤣

Mazda tech here. The Sky-Activ family of engines generally really reliable. In several years of being a tech at a dealer I can count how many full engines we have had to replace. Typical issues you will see with the 2.5L non-turbocharged engines will be a timing cover leak, but most often this will be covered under warranty. The 2.5L turbocharged engines occasionally get a cracked cylinder head, but these aren't too common. One thing to note about the Sky-Activ head gaskets, the head gaskets are stainless steel, and the heads or the block of the engine will usually fail before the head gasket does. They are easy cars to work on compared to most manufactures, and a great car for someone who would like to work on it themselves. They still do have transmission dipsticks (they are small, under the airbox), but its more than just about any other car manufacturer can say. Not really any specialty tools are needed for basic maintenance.

Been waiting for this one! I’m coming up on 400,000 miles on my 2015 Mazda 6 and I’ve never owned a more reliable car. Still runs and shifts great and still getting 33 mpg on the hwy. Beside a belt tensioner and an LCA, I’ve done nothing to this car except change the oil every 5K and drain and fill the transmission every 75K. I bought it used with 90K and it’s very comfortable and nimble. I will not hesitate to buy another one when it’s time.

when a mechanic says this engines are hard to find you know that is good.

24 yr tech here and those engines are pretty much indestructible never torn one apart so thank you for the insight

The Mazda Skyactiv engine line will be ones to remember. Long live Mazda!

Not an engineer nor have i teardown any engine. But i've seen many engine teardown and this is one of the simplest engine i've seen. No wonder why Mazda engine are so reliable. Simplicity is reliability.

I was a Mazda master tech here in California, I retired a few years ago. I can remember getting a lot of bad mouthing from the Subaru guys telling me how crappy Mazdas are. The reality of it was our Subaru shop had at least six guys working on Subaru engines at any given moment while us Mazda guys did maybe one engine per month and sometimes less than that. We did have a rash of water pump belts that broke causing catastrophic failure but usually the failures I had witnessed were due to lack of maintenance. I have five Mazda vehicles including a 91 LE pickup that's as reliable as it was when it was new, the only thing I've had to do to it has been just maintenance.

As someone who isn’t a Mazda fan, I am very impressed by this engine. Some engineering team took their time to build a very good engine. Maybe I’ll have to consider Mazda when buying my next vehicle.

So much more respect to this guy after he named all the cool Mazda's he's owned

As a long time Mazda driver (literally the past 13 years or so), I’ve been waiting for this. Thank you SO much!

My first car was my grandfathers 1986 Mazda 626 with a 5spd manual. He bought it brand new and rarely drove it. We inhereted it when he passed away in 2001 and it only had 18,000 miles on it. Loved that thing!

As a former dealer guy for ~6years, they have a incidence, low, but every dealer will see a couple, of porous/microcracking of head castings. 99.999% sure that is what happened here. MazdaTSB 01-013/21 Engineering of the SkyActiv family of engines is superb, as is, generally, quality control. Very premature drive belt failure is critical. Fortunately the water pump has its own belt, but AC and Alt belts never make 50K miles. Replace them before that or face a tow in.

My mom bought a 2022 CX-5 with the 2.5 liter N/A Skyactiv-G motor and I have to say it’s a very nice little car to zip around in. Aside from the overall good aesthetics and build quality inside and out the drive train and handling are great. Not the most powerful engine but always willing to run and it’s probably one of the only cars in its class that doesn’t get out of shape when the roads turns curvy. Pretty fun package to take on a road trip. Overall satisfying vehicle purchase.

Been driving my 2020 CX3 Sport since bought new and no issues @ 56K miles. Mazda quality shows in quietness of ride, 30 mpg and safety features and paint/finish. Perfect car for a retired couple with no grandchildren.

Have a first generation skyactiv Mazda 3 hatch, had it for 10 years at this point and it’s been impeccable. Driven 140k at this point with zero issues, definitely became a big Mazda fan over the years.

Mazda’s, hands down the best cars out there right now.

Could be a manufacture defect: head bolt wasn't tightened enough, causing the coolant leak. You'd have to check the head and deck flatness both to know if the head or block are warped.

My wife and I just replaced our 2015 BMW 428i with the new 2024 CX-30 because the constant maintenance issues with the BMW and high cost of replacement parts. We bought the CX-30 for the very reasons outlined by others:, it is easier to work on, parts cost less, and this is a high quality car. I appreciate you putting out this video so I could see how this engine is put together. It does look easier to work on.

I would have to agree these 2.5 skyactive engines are one of the better 4 cylinder options since the late 2010s. No oil burn great fuel economy and a decent amount of power for a lightweight economic chassis. Love the 2.5SA in my 3 with the 6 speed auto. Car feels very complete. 30+mpg with a heavy foot and sGT trim additional weight, best car I've owned in terms of being a "good car".