Why Toyota Engines are Reliable

Today I will show you what is inside the Toyota 2ar fe engine and how it works. Now this 2.5 liter engine has been used in many Toyotas since the Rav4 in 2008. We'll take it apart to see how it works and just What makes these

engines

so

reliable

that Toyota has been using them for the last decade? Now this engine is from a 2011 rav4 and has already been disassembled, so let's quickly remove all of these covers here, starting with the valve cover on top. now taking a look at the top of this valve cover this engine requires 520 or 0w20 weight oil that was the advantage of one of these

engines

over its predecessor the 2az engine it is much more efficient but still a bit More powerful.

It has dual vvti which you can see the oil control valves on the top of the valve cover here as well as the two cam position sensors at the rear. Now, looking under the rocker cover, we have this little tube here that runs through here. oil from this part here and distributes it throughout the rocker arm system under this valve cover here, so everything is lubricated and here you can see the two ports for the oil control valve, which means that this cover valve here, which is actually made of an alloy, not plastic, is part of the lubrication system and has to maintain oil pressure.

Now looking under this 2ar engine valve cover, we have the intake camshaft on this side and the exhaust camshaft on this side and you can see it here. They both have variable valve timing gears. One good thing is that the valve train is driven by a timing chain, meaning there are no timing belts to service over the life of this engine. Now, looking a little further down, we have the camshafts that act on these roller rocker arms which then act down on the valves below. Now these camshafts are actually secured in their own little tray here and can be removed once you remove the timing chain.

Next, I'm going to remove this. timing chain cover, you can see we have an access port for the intake vvti gear. We also have an access port for the timing chain tensioner here and all of this is already loose, the crank bolt and we have the timing. chain now, looking inside this valve cover, we have the integrated oil pump coming off the crankshaft right here at the front, we have its inlets and outlets here and it's actually a three stage system. variable oil pump, that also means that the timing chain cover is also part of the oil lubrication system in this engine.

Now with the movement of the timing chain cover you can see how simple the timing chain setup is. We just have the crankshaft here at the bottom. We have a hydraulic tensioner here that keeps the tension on these plastic timing chain guides and then we have the two variable timing valves for the intake and exhaust on top. There are no other idlers, water pumps or anything else here, just a simple cam and crank. At the top here now to remove this chain, I'm just going to remove these 12 millimeter bolts from the chain guides. I can remove them and these have plastic chain guides which I usually don't like but that's what new engines do.

We're going to use these days with this top slide here, now I can remove the chain from these gears and there's the timing chain guide here and then remove the chain tensioner. Now the crankshaft pulley just slides on and you can see that it's actually keyed to the oil pump now, this top pan here that carries the two camshafts is held on by a bunch of 10 millimeter bolts, so I'm going to keep going. go ahead and remove the next ones and then I could remove these cam covers here, you could see the channels for the oil lubrication, I'm going to remove this front one here, these actually feed the vvti gears from the top here through the cam cover valve and then from below here through these holes.

I actually didn't need to remove the camshaft covers because this whole pan here comes out as a set here you can see how we're different from the older Toyota engines instead of these camshafts acting directly down on these valves here, they actually push down on this roller rocker system here which will then push down on the valve. indirectly now having this separate tray here makes things easier especially when assembling the engine and you can see that you can remove the camshafts directly from this aluminum tray now with the camshafts removed we have clear access to the valvetrain at the top here and here you can see the roller rocker system now this is the hydraulic lifter that's actually going to plug in there now this is going to take an oil feed that has this little hole inside here to take all that clearance of this roller rocker system, that way you don't have to do a valve adjustment, it adjusts hydraulically for you and when you look at the bottom you can see it has a low friction roller design as well as the point of contact here where you are going.

To press the valve directly, we will now use a combination of spring pressure and oil pressure to compensate for that clearance. Next we will look at the air intake on this 2ar engine, now the throttle body plugs. on this side and then draws the air downwards and individually to the four cylinders. Now there are two main features in this entry. Here we have the acoustic air induction system which basically uses the vacuum from the engine to control a flap. in here and that will vary the air flow as it enters the engine depending on what rpm it is at.

I have another video on how the Toyota Acis system works where I took it down so you might want to check out the link above now, the other cool feature of this intake system is the rotary flow actuator. Now, this is just a servo motor that will control the individual fins inside each of these runners so that it can stimulate the rotating flow and therefore help. the engine warmed up much faster now the two series of ar engines were mostly port injected especially on the front wheel drive variants like the camry and rav4 and here you can see the four port injectors just before entering on the head next I'll just remove these 12 millimeter bolts that hold the fuel rail on and then I can remove the fuel injectors.

Now the interesting thing about these fuel injectors is that they have a very long snout as well as small holes here that help to really baffle and push the fuel down into the air intake as close as possible for better combustion. Now remove the 12 millimeter bolts that hold this air inlet and I'll just remove it and here on the back of the inlet you can See here the four rotary flow valves that will rotate with this rotary flow actuator to create a turbulent air flow depending on engine temperature. It's a bit cool that they decided to use a square input port here.

Now the head bolts on these are Torx T55. Okay, now I'm going to remove the cylinder head from the engine. Here we have removed the cylinder head and you can see that we have the top of the pistons here, which have a lot of junk on them. Now this engine uses an open platform design with the water. jacket around the pistons for good cooling now the interesting thing about this water jacket is that there's actually this insert inside here now what this insert does is effectively make the cooling jacket a little bit shallower so you can warm up a little faster engine now, what's interesting is this spacer that's deep in the engine where you'd think it would be hot, it's actually made of plastic and just take a look at all that crust on the top of the engine, Now look at the front.

From the engine block here we have the water inlet and thermostat housing integrated into this water pump which fortunately is not made of a plastic housing, although the newer Toyota is actually a complete electric unit, there is no pulley that boost your water pump right now. I'm going to remove a bunch of 12 millimeter bolts holding this water pump on and this is what it looks like now. Probably one of the weakest points of these Toyota engines is that these water pumps tend to leak after a while. Remove this coolant bypass hose here and then take out this dipstick here.

Now I'm going to remove these 14 millimeter bolts that hold this water pump housing on. Let's remove this thermostat. Here is a simple thermostat and then I will remove the water pump housing. here this one actually has oil lines going into the front of this engine now here this pocket is actually an oil separator for the pcv system so as the oil is drawn into here it's trying to capture some of that oil and bring it back. down so it doesn't burn back into the air intake system. This is also good because it works as an oil return where it bypasses the crankshaft so it doesn't splash and drops it directly into the case.

Now I'm just going to remove these 12 millimeter bolts and loosen them and here you can see the oil separator inside here. Now we have to turn the engine. Now looking at the bottom of the engine, we have steel oil. Tray, which is nice, we also have a cartridge style oil filter, so you have to get these special tools here to slide them in and then release them, then I can twist this plastic housing and you have your cartridge style oil filter here. which you can swap out next, I'm going to remove all the 10 millimeter bolts that hold the oil pan on and we're just going to pull that oil pan out, nothing interesting inside under the engine of this rav4.

We have this oil pickup tube that is made. plastic and oil is absorbed in here and goes directly to the oil pump in the front, now underneath we have this balance shaft assembly here that is meant to cancel out the vibrations of the engine, so we're going to remove all these bolts from 10 millimeters. to take a closer look now just remove that baffle there are a couple of 12 point bolts 12 and 14 millimeter bolts that I'm going to remove next and I'm going to remove the 12 point bolts let's go ahead and take this balance shaft assembly out here, this is great.

Look, as I turn this, the gears inside their rotation now this engine has an upper oil pan or you can call it a crankcase, so there's just a couple more bolts that hold them on and lift it up so with the crankcase puller it goes down to the block. and the crankshaft and I think I found the problem, I heard all the play here and these rods that connect the side play on the four, so this engine must have been making a big noise. Okay, I'm going to break down these 12 points. 12 millimeter bolts without connecting rod cap, they seem to be tight, okay, that bearing doesn't look too bad and that bearing doesn't look too bad either, okay, one doesn't look bad either and the last one looks good too, we'll just push them in below. so we can remove the pistons at the bottom, now I'm going to loosen these 14 millimeter bolts here, remove them here, now at the rear, here's the rear main seal and with everything else free I can lift the crankshaft and remove it. from the block I'm just going to take the pistons out here so here I have everything disassembled here I'm going to go ahead and take a closer look at each component now starting at the bottom of the engine here we have the crankcase or you can call it the upper oil pan and this plastic pickup tube now the lubrication system starts a trip in the crankcase here where it's going to suck oil down here and then right up front here where it's going to go in.

The oil pump now, one thing I don't like is that The oil pump is located in the timing cover rather than internal to the engine, which means that if you have a leak in the timing cover or something, you could lose oil pressure. anyway, the oil will increase its flow and then send it back through this hole here into the lower crankcase again, the crankcase will then send the oil back down to be filtered and then back into the main block, now taking a look at the two arch block here, things are pretty basic, we've got that oil that's going to come in from the oil filter here and it's going to be sent through the water pump housing and then into this oil galley here, now that galley is going to feed These oil jets here now, interestingly, the two outer pistons only have two jets, while the two inner pistons have three squares.

They will also feed the main bearings and also the crankshaft at the bottom. Here you have the PCV system that will extract oil and vapor here in the oil separator and hopefully bring the oilback to the crankcase before venting it to the valve cover and that oil separator is basically, there's a bunch of baffles, now the bottom of the crankcase comes off the crankshaft that we have. this balance shaft assembly now the reason we have a balance assembly on this engine is because a four cylinder engine is not naturally balanced. See, because if you look at this crankshaft here, you have piston number one and piston number four here and Pistons two and three will move together now, when they move in opposite directions like this, you will create a secondary force that will cause a lot of vibrations in this engine due to the way these pistons are configured. and we have this big gear here that is built on the balance weight of the number three cylinder that will drive those balance shafts.

Now the balance shafts can only be located under the number two and three cylinders. If you were to try to balance the outside, I'll actually be creating more forces now, you can see here, these two are the weights moving in front of each other and this is moving at twice the speed of the crankshaft, so it can reduce those secondary forces. for a more balanced engine. You can also see that it also has oil channels. and bearings such as the main crankshaft. Taking a look under the cylinder head, you can't see anything really damaged here, there's a lot of scab here built up over the years.

You can also see that there are these ports here that are going to feed oil to the head. Now the exhaust ports are somewhat traditional. You only have four output ports. The newer engines actually are. We're going to integrate the exhaust manifold into one piece and then the catalytic converter is just going to bolt up there, now into the head. You can see you have two main oil galleys that will feed all of these hydraulic lifters to make sure there is no knocking sound from the roller rocker arm system, plus you also have these oil feeds here that will feed the camshafts to lubricate them. and the VVTI system.

Next we have the camshaft pan and the camshafts themselves which are a nice solid piece here now the variable valve timing system is what is going to phase the input coming from the timing chain at the output, which is the camshaft. Now a downside to many Toyotas is that when this VVTI system wears out, it tends to give you a noise when you start, especially when it's cold. I now have another video on why it sounds so be sure to check it out at the link above. Now the water pump itself is also a weak point on some of these engines and one thing I don't like is that they ran a galley of main oil through the water pump housing for no apparent reason.

They could have simply shorted through the block itself, creating another point of failure and we finally get to the valve cover, as I mentioned. before you have to run oil through this little tube here to lubricate the roller rocker systems, now that's good for lubrication, however it opens up another point of failure if you have to run oil through each piece individual now to reduce Side-to-side forces within the cylinder walls Toyota has shifted the piston slightly towards the exhaust side, so the crankshaft is actually offset from the piston centerline and one of the main problems with the predecessor of this engine, the 2az, is that I would remove the head bolts from the aluminum block, that was a big deal because it would basically give the same symptoms as having a blown head gasket, except once you get in there you find out that It's actually disassembled and then you have to put it back on. is inserted here to fix the problem or potentially change the engine block.

Now another thing the Toyota addressed is the oil burning of the previous 2az engine, on that engine you wouldn't have enough oil return ports and they would all clog up and then the oil would just end up inside the combustion side of the chamber. Here you can see that there are clearly four ports here and four ports on this side and an improved oil control ring. Additionally they have also reduced the weight of the oil to increase the fuel economy now overall I think Toyota has done a pretty good job in the design of this engine, although it is very simplistic there is still very good fuel economy and, of course, really good reliability.

This engine has been used in many Toyotas, such as the rav4. and even the camry and a lot of fleet vehicles and it has proven itself over the last 10 years and hundreds of thousands of miles and that's pretty much all the components inside the Toyota 2ar engine and how it works. Be sure to follow me on Instagram for more information. the scenes pictures and subscribe for more videos like this check out my new glass top engine table I made with this engine, I finished it with a nice bronze and black theme and it even has a little steering wheel clock on the back later