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

Today's bad

engine

teardown

is going to be short and sweet and I really hope it's worth it because I finally have a Mazda

skyactiv

engine

in my hands. It turns out that they are very difficult to find and it is almost as if these motors do not fail, obviously, all motors. They fail for one reason or another, but all the bad Sky Active engines I've been able to find are bad because they were destroyed in an accident, they have bosses ripped off, the Pan's torn off intake is broken, that's pretty interesting, but we want to see internal damage caused by engine design or neglectful abuse, that's what's interesting and that's what I hope the deal is here.

This is a 2.5 liter

skyactiv

G from a 2021 Mazda cx-30 with only 30,000

miles

seems really premature for a catastrophic engine failure, but apparently that's what happened here. I'm not so sure it looks that good on the channel, but I'm a Mazda guy, not as much as my brother, but I've owned a lot of Mazdas. in my life because my dad is a retired Mazda Master Tech, so when I started getting into cars, buying cars and fixing cars, I had all kinds of cool Mazdas. I had a 323 GTX. I have had several. 626 turbos MX6 GTS 2nd gen cars with klv6 many Mazda B series trucks a ton of 1st and 2nd gen rx7 Miatas and even Turbo 2 cars many I wish I still had.

I know Mazda likes to try a lot of weird things that's just a Mazda thing and the Millennia s is proof of that, in fact I've had several of those cars, I love them very much and sometimes it works very well and that one seems be the case with Sky Active engines because these engines are not normal engines, these engines focus on complete combustion, the way the pistons look and they have the way the exhaust manifold looks which is not here, everything is designed for maximum combustion, so as we take this engine apart we'll look at a few things.

It looks a little different than what the average engine has now. I have the order to repair this particular well. Anyway I have a copy of this engine and I will read what it says. The customer claims they tried. Looks like it's ok. great, well, if it failed externally, we'd know that they usually fail from the inside out. I'm just being nitpicky, but I'm curious to see what's really wrong with this engine. I haven't broken it. I have not done it. I don't even know it might still have oil in it, so let's do the normal checks and then start taking this thing apart.

Well, you know how it works. The first thing we're going to do is remove the spark plugs and Look what we see uh oh the plug pulled the pin out and probably went into the engine so we're going to find a piece of metal there as you would expect these are the original spark plugs and They don't look too much. Bad, this is a slightly wet four cylinder, but nothing is bent or broken, nothing to see yet. Well, the next step is to turn this thing around. I'm not sure if it rotates. I'm sure it's fine.

I don't feel anything loose. That is interesting. Actually, I have to take this apart. I can't keep playing. I don't know if it's supposed to do that, but it's doing it well. Let's take a look at the intake ports a little charred by 30 000

miles

oh rust a little moisture there that one looks good ooh more rust well that's not a good sign and looking at the exhaust ports it seems pretty normal that one is wet maybe some moisture there one is also wet and that seems quite normal now this engine has not been left out. I'd just like to make that clear.

This came from inside a dealership. Now it's time to remove the valve cover. Did I miss one? Yeah, so this looks pretty good here. I do not see. no rocker out of place. I don't see any massacre or debris anywhere. I like these grease rails that drop oil on top of each lobe and I'm sure they extend the life of the rocker arm and camshaft. Yes, I don't see anything either. Terrible, I mean it looks like a 30,000 mile motor and even the chain guides, that all looks great now. I'm not very familiar with the timing system on these engines, so I'm going to crank this engine as far as I can think.

It makes sense and maybe we can verify that it's on time. Now we're going to look at the timing, so I turned this engine to where I think cylinder one is at TDC based on the little white dot in the center of the harmonic balancer. along the scale here and I'm used to reading Mazda scales here so I think around six and seven degrees is the TDC and I've also decided to take my long quarter extension and run it through the spark plug hole on number one and at Top

dead

center is literally the highest part, so let's move this to where it is at its highest point, which is right there.

Now we can look at the timing marks on the cam gears and we can see that Mark is aligned with the surface of the cylinder head and that mark over there is aligned, there is also a mark here with the arrow that is not pointing up, it is supposed to it should point a little bit in that direction and then when you go to the intake cam, that mark is pretty parallel to the surface of the cylinder head and the pin is almost up, so this engine is on time, there it is our white dot that indicates where TDC is.

Let's remove the timing cover, but first we must remove the oil from the crankshaft pulley, now later. Now, this is what I really like to see. Mazda engines before the Sky Active came out were heavily influenced by Ford and did not have lockable cranks. Even Mazda says that having lockable cranks is a drastic improvement over this engine's predecessor. Now let's take this timing cover off, there are a bunch of 10 millimeter bolts. The previous generation of engines had eight tens and is better. The foreigners did not need to re-enter, oh, this is still eight. Now we should be able to remove them easily.

This timing cover has to come off. We determined that it is not necessary for him to come out. So I clearly left it out. Oh wait, we put this out and it didn't need to come out. I can hear that it is necessary. to get out there's no way that has to get out, we'll find out, no, it's okay, look, I'm just sure I don't want to break it. The timing covers look brand new here, it's brand new, you know, after last week. hot chocolate molasses tar pit from a vr30 this is what i want to see it's all clean shiny and new this is great i don't see anything broken here yeah this looks fantastic next thing we're going to do is remove it the timing chain tensioner and I don't know where my safety bag went.

I'm very sad. I think it's gone forever, so normally you're supposed to put a pin right here and it blocks it, but I don't. I don't have a pen and I don't have one. I'm not going to re-time this engine, so we're just going to remove the bolts. I hope he doesn't shoot me in the face. Oh no, a lot of oil leaked, although yeah, it was okay, now we can remove this timing chain. I think this piece just slides like a rail. It looks fantastic. Now we will remove this other spool. Yes, it has a bit of RTV.

That is not like that. It's not supposed to be there outside that's like a new part, no, now we can remove this chain, what a chain, it's a work of art, the next thing I'm going to do is remove the high pressure fuel pump housing, is this here, well, that. It was simple, everything looks good there now, before we release these caps, we're going to remove these lubrication lines, they look pretty simple and while I'm in the neighborhood, I'm going to remove this chain guide and I don't know. I think I can go. Can I leave this there?

Yes, I can leave that there. Next, let's remove these cameras. I'm not sure I've mentioned this yet, but this is from a rental car. I don't know if he has any. related to what we're going to find and no I'm not foreshadowing no I've had a lot of questions now about this hammer this is actually a hammer that one of my viewers and friends Andy Campbell, he and his son made this. That you do this is crazy, thanks again. I know it's been a while since I said thank you, but thank you again. Well, everything looks pretty good here.

All Rockers are in good shape. All the camera diaries look perfect. I don't see any. more signs of damage this looks like a 30,000 mile engine. I don't see what's wrong, but the cam covers look good. The camshafts look good. This all looks great, but at 30k, how bad could it be? I shouldn't be asking questions like now I've learned a couple of things since having this channel and one of those things I've learned is to never trust that the engines are drained, so let's take the drain plug out, tilt the engine and take everything out. of the oil, whatever is left, whoa, it's actually drained, but is it really like that?

Oh, I see there's an oil that doesn't look very good, look at that, it's not the right consistency, I mean the new oil they're using in these. The cars are pretty close to the water but I don't think it should look like that, maybe it's normal or maybe the lighter color that looks like water on the rest of this oil drain pan is yeah that's not good now I'm going to rotate. the engine on its side so I can remove the head bolts a little easier and if you notice, I removed the rocker arms. I made it so they don't fly away when I turn the engine sideways.

It doesn't look good, so that comment was due to this not looking good, now it's time to loosen these head bolts and for those wondering, nothing has really changed, these are still T-55s to which it took a little less Strength. this just pops out, come on, weird, well there's the part of my tool that I think is going to drop the risers for a while. You finished? Uh-oh, that doesn't look good, it looks bad, so here's the head with the head gasket still on. and you can definitely see some coolant leaking out in this area.

Let's get this out of the way and see if we can figure out why. I can't understand why I want to say that the head gasket is not clearly broken, maybe cracked, there is some rust. Here around the valves, the rest of this really doesn't look too bad. I don't see anything flashy, so this is what the pistons look like and yes, they look very different, almost diesel, because this cup that the whole piston design is designed for. high compression and to prevent detonation they essentially have 14 to 1 compression and this is a crazy piston design compared to most engines that's what doesn't look so good in fact I would say it looks bad , is a good word to describe it, even bad. worse on that side look at the amount of wear that's happened here I'll tell you what we're going to do we're going to turn this engine over to where two and three are at TDC and one and four are at the bottom of the holes and we'll look at the others two holes oh yeah yeah well cylinder four looks pretty good and keep in mind this is the closest to where the external coolant leak would have been and that doesn't really look no.

It looks really bad, there's a little bit of wear there, but then we get to cylinder one, quite a bit of rust, water and moisture, not good, not good at all, now let's turn this around so that hopefully we can remove the oil pan. Don't make a mess in the process, I wouldn't do that to myself, well that was nice and easy, now it's time to remove a bunch of these eight millimeter headed bolts and pull the tray out, which is another thing I like see, an oil level sensor. These engines also have a dipstick, it just wasn't present with this engine, but I'll need blue for this, so that looks like expressionist art, it's not oil, oh, it's not all oil, so this is what's on the frying pan. and I'm no rocket surgeon, but oil and water mix and that's what seems to have happened here, so now this strange contraption at the bottom of this base plate is an oil pump and this it's the balance cartridge it's a 2.5 liter four cylinder and I guess it would vibrate without this now on previous engines with the more Ford design engines they had a balanced cartridge on the bottom here but it had a gear mesh with a gear on the crankshaft itself. off a chain.

I don't really see problems with either and I really don't think I'm going to take this apart because it may have some value again, it's a fairly new engine so I don't know where the market is on these things. You can see here are the balance axes. Once we get it apart, we'll turn it around a little bit and maybe the other side will have a better window into what's going on inside the truck. It also looks pretty clean the next. What we are going to do is remove the tensioner from this chain, we will remove that guide, take out the chain and go from there.

I'm sure this is yes, he's not under much stress. I do not know why I do it. these things, how can I remove this string without removing anything else? It doesn't seem like I can. I was really hoping to do it. Oh, wait, wait, wait, wait, wait, yeah, no, so the next thing I'm going to do is unscrew the oil. It looks like the pump has three 10 millimeter bolts and you should be able to tilt it to take the tension off that chain. That worked well. I don't plan to disassemble this oil pump again. I don't know where the value is.

I don't imagine this is very expensive new or worth using, butI'm not going to take it apart yet because I don't suspect there is any damage inside this pump now for this balance cartridge. I think there are only four more bolts, unfortunately they are 13 millimeters. It's fun to play with that. It has oil. Do you have oil? Yes, you have oil. This is what the balance shaft or balance cartridge looks like. It's pretty good. I don't see any problem with it. There is something else that is different about Skyactiv engines. Compared to its predecessor, these have a base plate, it's a two-piece top and bottom block, while its predecessor had a one-piece block and a removable main cap girdle, so I normally take out the rods and the pistons first and I can do it, but I think.

It's going to be a lot easier to remove the base plate and then I'll take out all the rods and pistons at once, so the first thing I'll do is remove the 10 millimeters and then we'll do the main cover. bolts I don't know if there's a good place to pry here most manufacturers leave you with something like here oh and there's a place here surrounded by sealants use my engine mount so I don't care just take it out that way oh that was a big mess uh yeah coolant isn't supposed to come out of this part of the block now everything looks pretty good this stays sealed out of the way I don't feel anything loose everything looks normal I'm going to unscrew all the rod caps we'll let that the crank comes out, push the connecting rods and the pistons and that's it, we're really there, I think we're there, well, at this point, the crankshaft should just boop.

Out of there Boop, out of there Okay, now we're going to take out the connecting rods and pistons. This should be pretty easy. Foreign. I can't believe I caught that thing that fell out of there. That one too. That's not good. First off, full of Milky Way, the lower main bearing shells are perfect, they look like they only have 30,000 miles on them, the crankshaft is perfect despite apparently having oil and water mixed in, no damage, no rods. The bearings are also perfect, exactly what you would expect from a thirty thousand mile motor. Now here is cylinder one.

Cylinders one and two came out pretty well as expected, although I think there is a bit of wear and some very sharp damage to that skirt. that's because of the rusty piston looks good cylinder two similar place there rusty piston also looks good but then we got to cylinders three and four and these literally fell off the engine and I sprayed them a little bit but then I stopped because I wanted to show you how dirty they were now, that's not normal and what I think is that it's a mixture of coolant and carbon and you have those rings completely stuck at the base of the ring and that's why they practically fell off.

Don't know. I see any damage to the piston itself, well, a little more wear on that cylinder four liner, a lot more carbon on that one and look at the way those rings are, they're just stuck, but nothing's bent, no rods. bent, I don't think. This was a Hydra blocking event, everything reached top

dead

center. Let's look at the cylinder head again. I reviewed this carefully. I can't find any cracks. The only thing I can tell when this thing fell apart is the head bolt. This one here was about half as tight as the rest now, I don't know if that's because this thing overheated and lost its tightness or lost its tightness and caused it to overheat, but either way this looks like overheating. situation and then started consuming coolant somehow.

I still haven't figured out how the coolant got into the combustion chamber unless it was just through a gap between the layers of the head gasket or maybe the head and gasket, gasket and block without tension, it's really hard let's say and the top cells in equally good condition, there's really nothing rye, there's nothing bad to see here, everything looks good, let's turn this over and look at those holes, so look at this quite carefully, this is the area of ​​concern here, I don't know. I don't see anything I don't see anything like a crack although that is quite damaged right there is that detonation thing do you think no I don't know if that is the case it seems that it is a similar point on that cylinder that cylinder and that cylinder to a lesser degree, like this that maybe this is running a little lean, maybe this got hot and the bore is distorted.

I think this is classic overheating. I just don't see what caused it, but this block is going to need some. working to be usable I don't know if it has any value these engines are very plentiful and have a lot of rust and cylinder rods I feel like we are missing part of the story I can't tell you how this happened. Can't. tell you that the engine was definitely defective and it wasn't some kind of misdiagnosis and we all know that everyone who drives a rental car treats it like it's their own car, that's not true at all, people who drive rental cars They generally drive them a lot. harder than their own car and they also don't always tell the truth about what happened when something happened, of course I don't have the full story, I don't even have the full engine, I just had a bare engine, that's how it comes from the Mazda Ascension.

It got a new engine but it was still a pretty good engine to take down, it didn't suffer much damage but it was cool to see some of its design features and it's the first time I've taken one down and I don't dislike it, I think it's a pretty good engine and also I haven't seen many bad ones, which tells me that overall the Sky Active engines are pretty good if you want to buy some parts for this engine or something. otherwise I will tear down or dismantle this 70,000 mile 6 speed 2013 Mustang GT car. You can go to importapart.com or you can email us at importapartsales gmail.com, just tell us what you are looking for, we have it too. a part request form on our website I really hope you enjoyed this

teardown

as always.

I love all the comments, even the criticisms. I love it all and I'll see you at the next oil control valve. Well, someone is in a good mood.