Subaru Engine #3 Teardown

What happens when your car is going 100 miles per hour in one direction and then accidentally all of a sudden you start backing up? Well, we did that and in addition to breaking part of our suspension and bending our subframe, now our

engine

doesn't run. What happened inside the

engine

during the accident we don't really know, but we do know that it is broken. Today we are going to tear this engine apart to see what really happened. I'm very curious and I hope you are too. Zach, this is Justin, welcome to Donut, welcome, let's look at the evidence we have.

We weren't here when Adam and Roberto pulled this engine out, so we'll watch this video to see the last time it flipped. yeah, yeah, it was a bit of a beat, that sounds pretty bad, that sounds horrible. Thoughts as if you were hitting. I think we have some Pistons, maybe hitting some arcs. I'm thinking it's a can, could it be, I mean something in there, that thing that's spinning is hitting something else, yeah, exactly, we'll see Zach, what's our next piece of evidence. Oh, okay, when the car starts up, you hear a lot of rocks being kicked, but then for a split second you hear like a screeching sound. noise, yes, the first thing that comes to mind is the timing belt, you know, jumping teeth on the timing gears, oh yeah, a little more evidence, we need to hear it from the horses' mouths, luckily Jeremiah and James were in the car and they're in the building today so I blocked this memory from my brain uh but I was driving the car I was training James I said James you can go full speed here baby he says send it buddy don't lift don't lift , No. lift, don't lift, so he doesn't lift coming in here and then what happens is I lift him.

He lives very hard and in a car with all-wheel drive when you lift, yes, you turn, you turn a little, yes, it's called takeoff oversteer, so when you're full on the gas, you lift the accelerator, the car wants to turn on that takeoff and when it does, it loses traction, so it's breaking traction, breaking traction at this point, James is like Jesus, grabs the wheels and we start sliding. the sides vary yeah so this is the point on the GoPro footage where you guys are looking at yeah yeah this is where we start turning so at this point I should have put the clutch in and I didn't so we hit that going sideways it was left in the air and as James said it didn't catch, so when it didn't catch on this landed boom, this wheel spun in the opposite direction backwards, that wheel was also completely deformed there, yes, well, with this new information. uh it looks like there's a chance we may have spun the old engine backwards, I didn't just crash, I crashed badly, so what does that even mean to spin an engine backwards?

Yes, good question, now generally an engine is designed to run in one direction and the timing components are designed with that in mind, technically an engine can support the crankshaft turning in the opposite direction, but the tensioner tensions the Timing belt is designed to keep tension on the belt from the other direction or in the correct direction, meaning you are turning it backwards. can cause slack in the timing belt, which can cause the teeth to jump or the belt to be ejected completely. This is a big problem in interference engines or engines whose valves and pistons can collide with each other if the engine doesn't have time now when James was turning, he forgot to engage the clutch, so with the momentum of the car now moving rearward, the wheels may have moved in reverse from the impact of the crash if the wheels turned in the wrong direction, so the driveshaft, transmission and in turn the crankshaft if this is really what what happened with that big shaking force in theory we can guarantee we would have skipped time all this talk about time is making my knuckles tingle let's stop talking and start diagnosing starting by figuring out the timing belt of this ej25 Yes, Justin. uh I just noticed something, yeah there's a hole where there shouldn't be a hole on this timing belt cover so let's start removing this and see what we discover.

Foreigner, wow, dude, that's just trashed, maybe it wasn't. Weird gravel, yeah, maybe it doesn't stink, but the timing belt is, I think, still in one piece, which is pretty impressive. I would have expected the belt to break before the gear but wow that's crazy, that's the side the car hit so maybe the crash had something to do with it, yeah maybe it was , but it didn't hit the frame or anything, so I've never seen anything like this before. I mean, I guess it makes sense to try to change direction so fast that the cam gear just turns. in 100 pieces first, when I saw this hole I thought, yeah, who knows what happened, maybe a rock jumped out of the ground and went into the timing cover, but I think it's pretty clear that the opposite is what happened, this hole was made from the Inside out, when the cam gear separated, it took away part of the cover.

Honestly, I'm surprised he hasn't done more. Narrow theory in time. The engine is out of time. It's an interference engine, so I'm pretty sure. The valves and the pistons were kissing, but I want to see it, I want to see where they kissed, so let's keep taking this thing apart and see what we're doing, it's just broken bits, there's also a lot of dirt when it comes to the four spark plugs. It looks pretty perfect, which means the tune was good. Take note of what I'm touching on here. This is an oil pan and an aftermarket one with a larger capacity and puzzling to keep the oil where it needs to be so you don't. starve the bearings on these engines, we have had this oil pan on all the engines we use in high-low and it still hasn't completely saved us, so on Subarus to remove the cam gears you have to get special tools from this way The cam gear does not rotate with the cam, so you can loosen all the bolts.

Yes, there is a big old tool to hold it. Still, take the big gun. Okay, you want to give it a push. Yes, three, two, one, three, two, one, yes, I broke the casing. Nice sweet tools Justin strikes again, this engine is junk anyway so Justin is going to manually remove that cam gear. You guys better watch out, you have safety glasses on, yeah that's funny, you're basically worse than wrecking a Subaru at 100 miles an hour, okay? Well, the cams here are in one piece, I mean, we've got pretty good wear there, but you know, nothing too crazy, it looks pretty straight, but it pulls that head, yeah, there's a lot of scoring, there's a lot of contact, That's probably why this is.

I didn't want to go out, this is where the cam gear was broken and having this metal cut like that would definitely cause it to not spin properly, yes there was a bit of a clanking noise there. Theory confirms time if you look at the top. Of the pistons you can see what looks like a little contact from the edges of the valves on the intake side, not as much as I expected. I expected to see hammered pistons and bent valves. Let's take a look at the valves. It's interesting. They look good, yes, they look good, you look totally good, and what was the boxing noise?

I guess it was just junk in the timing belt area. That's what confuses me because it sounded like an engine part hit the engine part, yeah, but you know. What I can't leave an apple half eaten, yes it's time to break the theory so it doesn't look like we've had any significant contact between the pistons and valves but sometimes looks can be deceiving so we'll go over a couple There are ways you can check for bent valves if you have an engine stripped down to here first. Let's do a little leak test with some water. We have this little area here where our valves are.

Let's fill this out. with water and then we are going to shoot compressed air into the exhaust side and into the intake side and see if bubbles appear around the valves, if they do that indicates a leaking, possibly bent valve. I have my nice little tool here, which is a piece of wood that I cut up and drilled a hole in that will help us seal on the side. Get some air in there and check for leaks, so let's see what we covered. Well, we'll start on the exhaust side. okay okay no bubbles on the exhaust side let's check the intake side oh there's a little bit of bubbles it looks like we had some contact we may have had some actual light contact although it didn't look very bad, we have some bubbles.

It comes around one of the intake valves, indicating a leak. The other way to check for bent valves is to take them out of the head and look at them, so what we're going to do here is use our valve spring compressor tool, basically a big C-Clamp that moves like this so you can squash the valve spring so we can take out the retainers and take out the valve so that our retainer is in the spring and here is our valve. Now you have to keep in mind that the amount of air we saw leaking past this valve was pretty minimal and doesn't indicate a really bad curvature, so to the naked eye this looks fine, but that doesn't mean it is.

Let's throw this into a drill, spin it and see if I can see any wobble drill and even then if we really can't see much curvature, that doesn't mean there isn't a slight curvature that's causing it to sit slightly and properly, oh that one It's the hair, just a now wobbles a little bit just to see what a good totally straight valve looks like. I'm going to take out one of the exhaust valves that didn't have any contact and we'll turn it and you'll see that it just seems true that it had just a slight problem in its vertiginous motion, it should be spinning in a straight line and there is absolutely no wobble in that tip, which is a good valve.

The theory confirms the times, so just as we expected when your timing belt goes bad in the interference engine there are unwanted interactions between the pistons and the valves and we couldn't see this before because it was very small and when doing this test of water we see that the valves are actually bent and the engine would have been able to run if we had just fixed the timing, but it wouldn't have run as efficiently as it should, that's right, and that valve never gets better. No, honestly, I expected it to be much worse. Well, we cranked the car and the engine.

We were forced to turn backwards, we were lucky with what happened, the cam gear blew up, which completely lost our time, which honestly saved most of the parts on this engine. I don't think they designed it to do that, but it worked, we did it. good luck on that day, well my curiosity has been satisfied, oh yes, and I hope yours has been too. I also hope you enjoyed this video, please like and subscribe, visit our website, check out our merchandise, have a good time, see you right now. Uh, put it back together, uh, no, so we broke everything.