best subaru engine

 

Today we are going to be tearing down this Subaru engine

 to discover what is inner and the way it works we are additionally going to be taking study a number of the not unusualplace failure factors on this engine to appear out for while shopping for used Subaru and right here we have got were given Subaru's not unusualplace ej25 engine it is a 2. five litre 4-cylinder horizontally adverse engine so the pistons certainly pass sideways

That's why the engine seems so extensive this engine did are available in one-of-a-kind versions along with turbocharged and twin overhead cam with variable valve time now one of the not unusualplace problems you may see with the Subaru engines is that they knock on your door in order that they cross knock knock and whilst you solution your connecting rod comes out so we are gonna tear into this scrap engine simply to peer how everything's laid out and what is inner and possibly do

Something thrilling with it while we are achieved now due to the fact that is a field or engine we've got pistons that pass sideways inner of this 1/2 of the block and every other piston that take a seat down in this aspect right here we've got the 2 engine heads that take a seat down on both aspect to every different with the consumption going from the pinnacle right here and the exhaust popping out the lowest right here we've got the camshaft positioned over right here

For every head and the crank 

withinside the centre right here on the again right here is wherein the transmission goes to discover now this engine due to the fact it is so extensive sits very low withinside the engine bay and it is located longitudinally so it is a type of installation like a rear wheel power vehicle so right here we've got an ej253 engine in the automobile simply to reveal you ways matters are located searching over right here at the driver's aspect you could see we've got the

Front timing cowl and the accent belts now that is quite clean to provide in this automobile but we do have one of the heads in this aspect right here and the downside of getting the top so near the body rail you could see right here is clearance to get right of entry to such things as your spark plugs right here's one spark plug right here and the opposite one is the manner on the again right here and you could see the state of affairs is comparable over right here

On the passenger aspect we've got the top over right here the spark plugs are positioned in the back of this airfield so servicing this engine in phrases of that thing isn't that clean now this engine is pushed off of a timing belt you could see you have got the crankshaft withinside the centre and the 2 cams at the outdoor right here we've got the water pump right here then we've got 3 loafer pulleys after which a tensioner pulley so we will

Just cross in advance and begin peeling this timing belt off that is a truly lengthy timing construct simply due to the fact the engine is so extensive i am going to begin operating on one head at a time so i am going to rotate this engine right here simply cast off all of the valve cowl bolts and I'm able to cast off the valve cowl itself now due to the fact that is an unmarried overhead cam model of this engine it has an unmarried camshaft that runs down the middle below right here

And it really is pushed off of the timing belt right here we've got the rocker palms that rotate in opposition to this pivot shaft right here and right here we've got the exhaust aspect in this aspect right here and the consumption aspect over in this aspect at the side of the spark plugs so that you can see as i rotate the camshaft to and fro right here simply how this rocker arm pivots to push the one's valves down and open them into the engine now I am

Going to cast off all of the 12-millimetre bolts that preserve this rocker meeting to the top now i will simply cast off this rocker meeting for the consumption aspect after which cast off the exhaust rocker meeting and with the rockers out of the manner you could see how the camshaft rotates now a not unusualplace difficulty with the more modern engines is that they have an inner hex that has a tendency to strip out fortuitously mine's only a 17 mil bolt

And i will simply stick a screwdriver in there then I'm able to cast off the cam tools and pa off that timing cowl now due to the fact this engine does now no longer have variable valve timing you best have one cam sensor over right here the opposite head does now no longer have a cam sensor subsequent up we come to every other capability difficulty in this engine and that is the head bolt a few human beings say that those want to be re-torqued

After a sure mileage and that'll save you the top gasket problems now, i have already loosened those up it is a 14 millimetre 12 factor bolt you may additionally be aware that the 2 centre ones right here have black tops and that is due to the fact they get tightened a bit tighter than the opposite 3 now i am going to split the top from the block and right here we come to one of the maximum not unusualplace problems with silver engines and that is that those head

Gaskets fail now loads of human beings want to blame the top gaskets themselves due to the fact the authentic ones had been manufactured from a composite-like fabric and while one of these layers had been compromised it'd purpose the engine oil coming via the oil gallery right here or the returns right here to combine with the coolant inner of the water jacket over right here now while cooling an oil combined they do not always do

Each different's activity well the coolant isn't truly right at lubricating and the oil isn't truly right at cooling the engine consequently both the engine itself overheats otherwise you run out of oil and lose lubrication to the pistons shifting up and down now from time to time those engines have an outside head gasket leak wherein coolant leaks outdoor the engine and you can see a bit little bit of a leak coming from below the engine now right here we have got were given

The pistons in this aspect of the engine 

and you could see that they may be a hundred and eighty ranges out of segment from every different and which means that on the alternative aspect of the engine you've got those on the alternative aspect of the segment that's high-quality due to the fact this engine is truly properly balanced and counteracts any secondary acceleration forces so for a 4 cylinder this engine should not vibrate

Nearly as a lot as an inline aspect of the engine now for a 2. five-litre 4-cylinder engine the diameter of those pistons are quite massive and that is due to the fact it is an over rectangular layout wherein the pistons themselves have a bigger diameter than the stroke an over rectangular engine layout is ideal due to the fact it is going to provide you much less shaking forces withinside the stroke course and it is also going to expand strength at

A little bit better rpm that's why those engines are famous with tuners and those who're doing rally races now the actual cause why a quick stroke is used is due to packaging due to the fact the engine is so extensive and sits horizontally it dictates the scale of the engine bay so in case you cross to any extent further at the stroke your engine goes to come to be wider and it'll restriction a number of the suspension geometry at the automobile i am simply going to cast off all of the 14

Millimetre bolts that preserve the loafer pulleys on from the timing aspect of the engine simply speedy cast off the cam cowl in this aspect and the cam bolt and we will take off all of the head bolts and i will cast off the top this right here's wherein the oil clear out lives now I am going to cast off the oil pan bolts you could see it is searching type of sludgy inner of there is proof right here

That both the oil turned into sludging up or it turned into combined with coolant sooner or later now the oil pan and choose up tube cast off you could see we've got clean get right of entry to to the crankshaft that rotates inner of this block right here now this engine block right here splits into halves with a view to getting the crankshaft out now one more flaw withinside the Subaru engines is oil hunger now i do not have the pickup tube however it'd commonly sit up straight right here

At the lowest of the sump and suck oil down into the inlet for the oil pump it'll then pressurize that oil and ship it out to the heads in addition to the principle bearings and the connecting rod bearings at the crankshaft now one hassle that would stand up is in case you run low on the oil your bearings aren't going to get truly properly lubricated after which it really is going to purpose them to warm up and put on out inflicting those marks which you see on

This crankshaft in addition to this connecting rod may be then going to lose its tolerance among every different after which it is going to begin knocking to and fro barely like that now this hassle is attenuated with Subaru's oil burning hassle and that is to do with this oil manipulate ring you could see on the pinnacle right here we've got the compression jewellery now right here we've got the oil to manipulate ring it really is meant to

Scrape the oil far from the inner of the cylinder and maintain it on this segment over right here withinside the sump in preference to setting it at the combustion aspect wherein it may get burned but in a few instances you could see how skinny this oil manipulate ring is it may get clogged up with sludge and those go back holes right here also can get clogged up consequently in place of the oil returning again via the piston skirts and falling back off into the sump

It finally ends up withinside the combustion chamber getting burnt and then you definitely run out of oil now a boxer engine makes this even worse due to the fact it is horizontally adverse and gravity isn't always precisely supporting you to keep any of that oil which you're pumping out from the sump you could see Subaru's attempted to feature baffles inner of right here in addition to form the oil pan down right into a factor right here wherein the oil pickup tube

Would be that way if you're taking a rally course and you're moving from side to side there's less chance of the oil pump just sucking up air instead of oil i'm just going to remove all the 10 millimeter bolts that hold the oil pump onto the crank and we could just pry that oil pump off and there's the oil pump now we're going to remove the water pump and the water inlet assembly Now gravity doesn't exactly help the head gasket situation either when the car is parked all of its fluids are just going to kind of stop right here at the bottom of where the head gasket is and if those fluids like the coolant or the engine oil is contaminated it can start to eat through the head gasket and cause a leak now as we've already seen this engine is pretty weird and what's even weirder now is that we Need to remove this connecting rod pin here to get the piston heads off of the connecting rod in order to split the block and take out the crankshaft now in order to get access to that connecting rod pin you need to open up these access ports over here it's a 14 millimeter heck now if you haven't got a 14 millimeter hex you could just take a 14 millimeter head bolt thread two nuts on the back and put a Wrench in the middle and this is your 14 millimeter
Would be that way if you're taking a rally course and you're moving from side to side there's less chance of the oil pump just sucking up air instead of oil i'm just going to remove all the 10 millimeter bolts that hold the oil pump onto the crank and we could just pry that oil pump off and there's the oil pump now we're going to remove the water pump and the water inlet assembly Now gravity doesn't exactly help the head gasket situation either when the car is parked all of its fluids are just going to kind of stop right here at the bottom of where the head gasket is and if those fluids like the coolant or the engine oil is contaminated it can start to eat through the head gasket and cause a leak now as we've already seen this engine is pretty weird and what's even weirder now is that we Need to remove this connecting rod pin here to get the piston heads off of the connecting rod in order to split the block and take out the crankshaft now in order to get access to that connecting rod pin you need to open up these access ports over here it's a 14 millimeter heck now if you haven't got a 14 millimeter hex you could just take a 14 millimeter head bolt thread two nuts on the back and put a Wrench in the middle and this is your 14 millimeter

Would be that way if you're taking a rally course and you're moving from side to side there's less chance of the oil pump just sucking up air instead of oil i'm just going to remove all the 10 millimeter bolts that hold the oil pump onto the crank and we could just pry that oil pump off and there's the oil pump now we're going to remove the water pump and the water inlet assembly Now gravity doesn't exactly help the head gasket situation either when the car is parked all of its fluids are just going to kind of stop right here at the bottom of where the head gasket is and if those fluids like the coolant or the engine oil is contaminated it can start to eat through the head gasket and cause a leak now as we've already seen this engine is pretty weird and what's even weirder now is that we Need to remove this connecting rod pin here to get the piston heads off of the connecting rod in order to split the block and take out the crankshaft now in order to get access to that connecting rod pin you need to open up these access ports over here it's a 14 millimeter heck now if you haven't got a 14 millimeter hex you could just take a 14 millimeter head bolt thread two nuts on the back and put a
 

 hex that you insert into here and you can loosen off that plug turn the crank to align the piston to line up with this hole it'd be a little difficult to see but that's the connecting rod pin lined up there i'll just reach in with these pliers here then i can pull it out now to get the pin out you'd have to either push it out from the other side Or you can get a special tool that has a hook on it now in order to get access to the access holes on this side here i'm going to have to remove this engine from its engine stand but before i do that i'm going to try to break all the bolts free to split this block in half now this engine block's got quite a few bolts going around it and inside of it holding it together you can see there's five obvious ones here across the top Over here there's another two and then another one hiding up here now inside the water jacket themselves there's also some bolts hiding inside of here there's even more bolts hiding inside of there it's really long and there's one more bolt over here on the oil pan and one at the back here so with the engine block removed from the stand we have this access port at the back here and from here you can see The other connecting rod pin what we're gonna do is take a small rod and just catch it just like that up i'm going to back off from the crank and you'll see that the piston is now stuck in its spot and we'll try rotating the piston i can lift up the connecting rod and we can pop it through the block now another weak spot on some of the subaru engines was pissed and slapped and that's because of the tolerance around This piston skirt here was eaten up pretty quickly and the teflon coating wore away and that allowed a little bit of wiggle as the piston moves down and up its shaft as it wiggles it's going to make a little bit of a clatter especially on cold starts and that's what's called piston slap it'll go away when the engine warms up i wonder if i could separate this block without removing the pistons on this Side all right so that's one half right here here's the rear main seal now because the pistons can't come up through the block this way i'm going to remove them down this way by disconnecting the connecting rod here at the crankshaft and you can pull the piston out this way suddenly everything got so oily so i'm just going to use what's left of my brother's old sock here and wipe off all the oil residue and you Can see we've got our box engine all taken apart here now taking a look at those connecting rod bearings you can see they are absolutely chewed up and you could tell that this engine has run low on oil at some point and when there's no lubrication on these bearings they just start eating themselves up and that's what causes connecting rod now so here we've got the main bearing and you could tell it also has been starved with Oil it's got a lot of sharp grooves in it now the crankshaft itself really only suffered damage on the one connecting rod now that connecting rod must have been knocking so badly they're actually chewed into the block into this part here now besides this piston ring some subarus suffer from broken ring lands now the ringline is this area here where the notch is

For the piston ring to sit inside and sometimes there's a crack across there and a chunk of it might actually come loose causing you to lose compression and that's just mainly due to the material used on the piston head now in terms of how this engine gets its oil it's going to start here at the oil pickup tube inlet that's then going to be drawn over to this section here which corresponds to This section here on the oil pump the oil pumps then going to pressurize that oil and send it back out this port over here which corresponds to this port on this half of the engine the oil is then going to make its way through the oil filter and then back out through here and then through another oil galley that runs crossway this way and then through another oil galley that runs down to all of these main bearings Now some of that oil is then going to be sent over through this hole which is going to correspond to this hole on the other half of the block and that's got more galleys over here that's going to lubricate these two main bearings here surprisingly this bearing is not lubricated there's no hole for it and this one here gets its feet from the one that goes to the head you can see on this one here this is the galley that's Going to take oil up through this little hole over here and if we come across the block that hole corresponds to this hole over here which is going to take oil into the head to lubricate all the rocker arms and camshaft and with the block split you can see this is the passageway that crosses over cooling from the water pump side of the engine to the other half of the engine now one Other thing that i've noticed on this engine is just how far forward it sits relative to the center line of the front wheel it's just like a front wheel drive car almost where you have a huge front overhang most of the engine here is in front of it and that's because of the all-wheel drive setup this engine situated longitudinally and you can see here this is where the transmission sits and the drive axle That goes out to that front wheel in comparison here's my lexus gs350 which has a longitudinally mounted v6 engine you can see that the front of the engine here almost lines up with the center line of the wheel so everything is kind of pushed back in this engine bay giving it a fairly short overhang in the front and because the transmission is underneath the vehicle and all-wheel drive models there's a prop shaft that Runs to the front and then underneath the engine to the front wheel now if you compare that boxer style engine format to say an inline engine this one being a volvo five cylinder you can see that its footprint is much slimmer than that boxer engine but this engine sits upright which is going to give you some design restrictions with your vehicle meaning that your hood line has to be a little bit higher to clear it and it's Also going to raise the center of gravity funny thing is this super actually has an inline 6 sitting upright underneath the hood although it's a very low hood line link in the description above if you want to see more under the hood now i have a full teardown and analysis of this volvo engine but generally speaking you could see that the inline engine has the Pistons moving up and down 

For the piston ring to sit inside and sometimes there's a crack across there and a chunk of it might actually come loose causing you to lose compression and that's just mainly due to the material used on the piston head now in terms of how this engine gets its oil it's going to start here at the oil pickup tube inlet that's then going to be drawn over to this section here which corresponds to This section here on the oil pump the oil pumps then going to pressurize that oil and send it back out this port over here which corresponds to this port on this half of the engine the oil is then going to make its way through the oil filter and then back out through here and then through another oil galley that runs crossway this way and then through another oil galley that runs down to all of these main bearings Now some of that oil is then going to be sent over through this hole which is going to correspond to this hole on the other half of the block and that's got more galleys over here that's going to lubricate these two main bearings here surprisingly this bearing is not lubricated there's no hole for it and this one here gets its feet from the one that goes to the head you can see on this one here this is the galley that's Going to take oil up through this little hole over here and if we come across the block that hole corresponds to this hole over here which is going to take oil into the head to lubricate all the rocker arms and camshaft and with the block split you can see this is the passageway that crosses over cooling from the water pump side of the engine to the other half of the engine now one Other thing that i've noticed on this engine is just how far forward it sits relative to the center line of the front wheel it's just like a front wheel drive car almost where you have a huge front overhang most of the engine here is in front of it and that's because of the all-wheel drive setup this engine situated longitudinally and you can see here this is where the transmission sits and the drive axle That goes out to that front wheel in comparison here's my lexus gs350 which has a longitudinally mounted v6 engine you can see that the front of the engine here almost lines up with the center line of the wheel so everything is kind of pushed back in this engine bay giving it a fairly short overhang in the front and because the transmission is underneath the vehicle and all-wheel drive models there's a prop shaft that Runs to the front and then underneath the engine to the front wheel now if you compare that boxer style engine format to say an inline engine this one being a volvo five cylinder you can see that its footprint is much slimmer than that boxer engine but this engine sits upright which is going to give you some design restrictions with your vehicle meaning that your hood line has to be a little bit higher to clear it and it's Also going to raise the center of gravity funny thing is this super actually has an inline 6 sitting upright underneath the hood although it's a very low hood line link in the description above if you want to see more under the hood now i have a full teardown and analysis of this volvo engine but generally speaking you could see that the inline engine has the
  

which means that the secondary forces and thus accelerations are going to vibrate the engine up and down now here we've got a v6 engine so three cylinders on this side and three cylinders on that bank and you can see that these cams lead up to the crank there at the bottom forming the v shape now the v engine isn't going to be nearly as tall as an inline engine But it's also going to be more balanced than say an inline four or even a boxer engine because the secondary forces cancel each other out making it much smoother and that's pretty much what's inside of a subaru boxer engine and what makes it so unique from a regular four-cylinder now if you've got one of these engines make sure you keep up on maintenance because as you could see this could get pretty expensive now make Sure you follow me on instagram for more behind the scenes footage and subscribe to see more videos just like this one and check out my new subaru engine coffee table just like the engine itself this table sits nice and low flat and wide and i've even turned the flywheel into a working clock