07 Engine Swap into an 03

So with my engine pushing 330k miles and a headgasket leak, I decided to swap in a newer engine to avoid the inevitable - my engine blowing. While I had always hoped to the leave the engine in it to see how far it could make it, with the hopes I could join the 400k club, it was ultimately the best option to go ahead and do it while I had the time before something went wrong and I ended up stranded on the road or in the woods somewhere.

This was done during my spring break. I spent the majority of about 5 days in the garage working, so let's say this project was around 60+ hours. I know some people on the forum have mentioned they have been able to swap an engine in 8 hours or so from start to finish, but we had never done this before, and we did a lot more than just swap an engine. Also, the 60+ hours includes the clean up and trips to various parts stores to pick up things we had forgotten to buy

Background
The old engine was pulled out of an 07 with 175k miles. The guy was selling it on Facebook marketplace because his son unfortunately rolled his 4runner into a ditch. The engine was in good condition, and being the 07, had the updated headgasket design.

However, as some know, the 05+ engines are not directly compatible with the 03-04 trucks. This is because the 05+ uses an updated VVT-i design. This change is thankfully only found in the intake cam timing gears and the camshaft position sensors. So, to make an 05+ engine compatible with your 03-04 truck, all you need to do is swap your model's intake cam gears and cam sensors over, then viola, compatible engine!



Now the process is actually pretty straight forward, and tutorials for each separate job can easily be found, so I won't be doing an entire detailed write-up. But I haven't really seen many threads about this project as a whole, so I just wanted a place to compile and share some general information, as well as my experience over the process as a whole.


[MENTION=429038]y=mx+b[/MENTION] Not sure if this is worthy to make it into your tutorials list, but maybe it's useful

Parts List and Tools

Here is a list of everything I bought:

PartSouq
Main Timing Chain- 1350631010 - $80
Cam Timing Chains - 1350731010 - $25 (x2)
Timing chain Main Guide - 1355931010 - $16
Timing Chain Guide NO.2 - 1356131010 - $37
Timing Chain Main Tensioner - 1354031011 - $43
Timing Chain Cam Tensioner - 1355031010 - $50
Timing Chain Cam Tensioner #2 - 1356031010 - $19
Intake Cam Timing Gears - 1305031010 - $112 (x2)
Cam Position Sensor - 9091905026 - $55 (x2)
Timing Gear Idler Sprocket - 1353031011 - $10
Timing Gear Crankshaft Sprocket - 1352131060 - $13
Main Timing Chain Dampener - 1356231010 - $9 (x2)
Timing Cover Oil Seal - 9031142036 - $5
Oil Pump Gasket - 1519331010 - $2
Oil Filter Bracket Inner Gasket - 9672224030 - $2
Oil Filter Bracket Outer Gasket - 1569231010 - $3
Water Pump - 1610039406 / 1610009471 - $126
Exhaust Gaskets - 1717331010 - $10 (x2)
Spark plugs - 9091901235 - $3 (x6)
Air Surge to Intake Manifold Gasket - 1717631160 - $8
Intake Manifold to Head Gasket, NO.1 - 1717731010 - $5
Intake Manifold to Head Gasket, NO.2 - 1717831010 - $5
Valve Cover Gasket NO.1 - 1121331030 - $12
Valve Cover Gasket NO.2 - 1121431010 - $12
Belt Tensioner - 1662031013 - $115
Idler Pulley, NO.1 - 1660331040 - $34
Idler Pulley, NO.2 - 166040P011 - $30 (x2)
Engine mounts Front - 1236131081 - $67 (x2)
Water Inlet Pipe, O-Ring - 9676135031 - $2
Water Inlet Housing Gasket, NO.1 - 1632531010 - $1
Water By-Pass Hose, NO.1 - 1626131020 - $4
Water By-Pass Hose, NO.2 - 1626431010 - $4
Water By-Pass Hose, NO.3 - 1626731010 - $6
Water By-Pass Hose, NO.4 - 1628131011 - $4
Water By-Pass Hose, NO.5 - 1628231010 - $4
Throttle Body Gasket - 2227131012 - $3
Thermostat - 1603131011 - $25
Total: $1416

URD
3° Retard Exhaust Cam Gears - $115
JBA 409 Ceramic LT Headers - $465
Total: $580 with discounts

Amazon
Denso A/C Compressor - 4711413 - $207
Hayden 678 Transmission cooler - 678 - $50
Sunsong Power Steering Pump Seal Kit - 8401506 - $21
Denso 02 Sensor - 234-4804 - $48
Total: $248

RockAuto
UAC A/C Condenser - CN3282PFC - $60
UAC Expansion Valve - EX10154C - $10
UAC A/C O-ring set - RS2584 - $15
Total: $107 with discounts

AdvanceAutoParts
Dayco Serpentine belt - 5070835 - $38
7 quarts of 5W30 - Valvoline MaxLife Blend - $40
Purolator Oil Filter - PL10241 - $11
Purolator Air Filter - A35578 - $26
Carquest Cabin Air Filter - 89905 - $19
Dorman Spark Plug non-fouler set - 42009 - $9 (x2)
Permatex Water Pump and Thermostat Gasket Maker (1oz)- $10
Permatex Ultra Grey Gasket Maker (13oz tube) - $25
Fel-Pro Rear Main Seal - 40686 - $17
Total: $170 with discounts

Napa
Refurb Denso Alternator - 210-0541 - $200
Total: $220

All in all, the project cost us around $2743 in parts, plus $1200 for the engine, so $3943 in total. From the quotes we saw while shopping, for that price, I would've probably only gotten a junkyard rebuilt engine.

You could definitely save some money and get by with not replacing some of these parts - like the water by-pass hoses and engine mounts and what not, but we decided to go ahead and get them because with the age of my truck, it was easier to replace them now and not worry about it than try and replace them with the engine in.

Also, I went ahead and replaced a bunch of other stuff, like the alternator, A/C compressor, condenser, etc. This was done in the mindset of "My truck is 20 years old, we don't know what's been replaced, and it's easier to do it now while were already taking the engine bay apart"

Tools
You don't need anything super special for this project (except, you know, an engine hoist and stand). Some screwdrivers, a good set of deep and shallow sockets, a ratchet wrench, a set of box wrenches and hex wrenches, and a torque wrench will get you by. Some tools that will makes things a lot easier though, is a set of stubby ratchets that pivot, a spark plug socket, a breaker bar, an impact driver, and a trim panel remover (for wire clips and stuff)

Prepping the New Engine

Timing Chain + Gears
The first thing we did was work on the new engine to prep it before we pulled my engine out. This is my daily rig, so I didn't want it to be down longer than it had to be.

The timing chain job isn't hard, just time consuming between checking marks, spinning crankshaft, checking marks, spinning crankshaft, checking marks, and so on.

This is the stage where we replaced all 3 tensioners and chains, along with the idler and crankshaft sprocket. This is also when the retarded exhaust cam gears, and the correct model intake cam gears were installed. We also went ahead and installed the proper camshaft sensors at this point too.

Using the grey Permatex gasket maker, the timing cover, and timing chain access cover, were sealed upon reinstallation.




Water Pump, Idler Pulleys, and Tensioner
Next was the water pump, idler pulleys, and the tensioner. Super easy job, just make sure to torque to spec. Also be sure to put the idler pulleys in the right spot: Idler NO.1 is the lowest one, and Idler NO.2 is the upper two



That was about all we could do to the new engine without pulling parts off my engine, so we got to work on getting the old engine ready to come out

Prepping the old engine for removal

Getting the engine ready to come out isn't hard, it's just a matter of patience and being thorough. You want to make sure EVERYTHING is disconnected before pulling on it with a hoist.

Tips
While working on a project like this, I recommend keeping a roll of bright colored painters tape handy. Put a piece on everything you unplug - this is a good tip for making sure you get everything plugged back in and don't forget something. It's also useful for covering things like the intake ports on the engine while the intake manifold is off. Another good tip: Keep a sharpie and box of sandwich bags nearby. The quart-sized freezer Ziploc bags are great - good size, durable, and have a nice white spot for labels. Each bolt you take out should either be placed in its respective place on the new engine, or in a labeled bag. That will make putting the new engine in a ton easier because you're not hunting down bolts. Also, it's a good idea to let any corroded or nasty bolts soak with some PB Blaster or WD-40 for a little before starting - especially the exhaust header nuts and the bolts holding the header/y-pipe together.

Prep
First things first, to get the engine out, you're gonna wanna take the hood off. This is required to have room for the engine hoist, and gives you a lot of extra room to lean over the engine while working. Next, disconnect the battery. Now drain the radiator and take the radiator, fan shroud, and fan out. This helps give you more room to work on other things, and gets the radiator out of the way early to help protect it from getting hit or smashed. Go ahead and empty the block of any coolant using the drains on the sides of the engine, and drain the oil as well. Then, take off the air intake hose, intake/filter box, air surge box, throttle body, and intake manifold. Go ahead and disconnect all the serpentine driven parts like the alternator and P/S pump. You don't have to completely remove these like I did, but it may be easier and help create a little more working room if you do. After that, take the exhaust headers out. Now is a good time to begin disconnecting any plugs and grounds that you see. Be sure and look all around the engine. There can be some hidden/hard to see plugs and grounds, so be thorough, and don't forget behind and below the engine too. While looking for grounds and plugs, go ahead and take off any brackets or hoses that you see attached to the engine as well.



Once you have done all that, it is time to work on the bell housing. Start by taking the starter out. There are two bolts that hold it in. After removing the starter, there is a plastic clip that sits in the hole the starter goes in. Remove this to access the torque converter bolts, but be careful not to break it. Mine was super brittle, and I ended up super gluing it back together. Now take out the bell housing bolts. There are two different sizes, the lower half are smaller than the top half. There should be 9 bolts in total, excluding the starter bolts.

It is probably a good idea to place a jack under the transmission to help support it when you take the engine out

Now it is time to take the torque converter loose from the flywheel. By going through the starter hole, you are able to access these bolts. You will need to spin the crankshaft to access these bolts one at a time. I made sure to take these bolts out in an order, then reinstall them in the same order, but I am pretty sure it doesn't matter. There is one black bolt, and the rest are silver, so I decided to take the black bolt out first. After removing each bolt, I stabbed them into a cardboard sheet and labeled the bolt, while also using a sharpie to label the fly wheel as well.



Once you are 100% sure you have disconnected every plug, ground, wire clip, hose, and bracket, you are ready to pull the engine.

Pulling the Old Engine

Pulling the old engine
Once you have everything disconnected from the engine, you can start pulling the motor. Start by removing the motor mount nuts. I decided to use 4" carabiners in the holes at the corners of the motor as my lifting points. Because of the shape of the front driver side hole though, I had to use an S hook on that side



Now go ahead and start lifting the engine out with the engine hoist. Be sure and do this slowly while periodically looking around the engine bay for anything you may have forgotten to disconnect.

The bell housing may be a little reluctant to separate from the engine because of the dowel pins, but as long as you are sure you removed all the bell housing and torque converter bolts, a pry bar or screwdriver can help. Shaking the engine can also be an effective technique.



Old Engine Condition
The Old engine had a rear main seal leak, a head gasket leak, and some valve cover leaks. Those were probably the most notable issues. Honestly, for 330k miles, I'd say the engine was in pretty good shape

Final Prep for New Engine

Prepping the new engine
With the old engine out, it was time to do the final prep to get the new engine ready to drop in

With the old engine hanging on the hoist and the new engine still on the engine stand, we swapped over any remaining hoses, brackets or parts that we needed off the old engine. We also swapped my flywheel and my front water junction block over to the new engine. We decided to leave the valve covers off until after dropping the engine in because the chain of the hoist put pressure on the old ones when we pulled it, so to prevent something from happening to the new ones, we left them off.



While working on the new engine, we realized the intake nipple on the fuel rail was broken off (most likely from when the seller pulled the engine), so we had to swap my old fuel rail over to the new engine. We swapped the newer fuel injectors into my rail though because they were in better condition.

Dropping The New Engine In

Dropping The New Engine In
With the new engine prepped, it was finally time to drop the new engine in. We dropped the old engine off the hoist on an old tire, and then hung the new engine. We couldn't put the new rear main seal in with the engine on the stand, so after hanging the new engine, that is when we changed the rear main seal



Putting the new engine in is the exact reverse of taking it out. Slowly let it down while checking for anything that is in the way of where the engine needs to be.

If you are using an old, janky hoist that needs a pair of vice grips to loosen the valve and lower it, make sure these vice grips do not spin the valve after you take your hand off and drop the engine into the engine bay (This may or may not have happened while my dad was letting the engine down).

Make sure you line up the bell housing dowel pins with the holes in the engine. This may require adjusting the jack under the transmission up/down to get the right angle. We had to use a ratchet strap as well to raise the front of the motor and line up with the bell housing. Once the bell housing is lined up, go ahead and drop the engine mounts into their spots and finger tighten the mount nuts.

Edit:
Be sure and check that all 4 holes are empty, cause for some reason, on the engine I got, the front driver hole was filled in - not full of gasket maker, but aluminum, like the engine cast/mill process didn't make the hole. The top of the hole was there, but the bottom wasn't. Not sure if this is common, or just a fluke I happened to get though

To get around that, I just threaded the upper alternator bolt in and put the chain around the entire thing, like seen above

Putting the Engine Bay Back Together

Assembling the engine bay
All that is left to do is getting everything put back together. While putting everything back, be sure to plug in all connectors and connect any hoses that may be obscured by your next step

I started with the bell housing bolts, torque converter bolts, and then the starter. Before anything else, I went ahead and put the long tube headers in while I had the extra room. I had to take the front driveshaft loose to wiggle them up on the driver side, but the passenger side went right in.



Then I started to put all the connectors, grounds, and hoses back, along with any wire clips I saw. Unfortunately, my camshaft sensor plugs were broken because of the 20 year old brittle plastic, so I had to resort to taping them on



Then I started reinstalling all the serpentine driven components. Make sure you plug in the crankshaft position sensor before putting the A/C compressor in, because the sensor is inaccessible with it installed. After that, we installed the valve covers. Then I went ahead and installed the oil filter and poured 6qts of oil into the engine. After adding the oil, we spun the crankshaft about 10 times to prime the oil pump and filter, and pre-lube the engine so we didn't dry start it.

After priming the oil system, we installed the new spark plugs and put my coil packs in. Then we installed the air surge box, throttle body, and air intake. Now you can put the radiator and fan shroud back in, ensuring to put the hoses back on the radiator. Now fill the radiator with coolant. During this part, I also decided to install the Hayden 679 transmission cooler in-line with the radiator. Reconnect the battery, and everything should be good to go



Because I'm probably forgetting to list something, and you're probably forgetting to put something back, double-check you put everything back, then triple-check, then check again. Once you are certain everything is plugged back in, all the hoses are connected, and everything is ready to go, it's time to start her up!

Starting The New Engine For The First Time

Starting the new engine
Starting the engine for the first time is scary

(Especially when you're like me and accidentally leave the 4wd computer and another computer unplugged after working under the dash, so when you go to start it, it doesn't even try and crank. And it also throws camshaft and crankshaft sensor DTC's, so you spend 2 hours swapping sensors and stuff, only to finally remember you left the computers unplugged, so you plug them back in and it starts first try *facepalm* Don't be like me!)

So when you start it, make sure to check all your hoses for leaks, any liquids spraying out, monitor gauges and warning lights, etc. After starting it, turn the heater on and let it get up to temp so the thermostat opens and fills the empty block with coolant. After doing this, turn it off and check all the fluid levels. It's probably gonna need oil, maybe ATF, and definitely coolant.

Now that you have a running engine that you have confirmed is in a good working condition without errors, top off your fluids, recharge the A/C system, put the trim pieces to the engine bay back together, reinstall your skid plates, and do a final check on everything.

And once you put your hood back on, step back and take a minute to bask in the glory of knowing you just swapped your engine

After putting everything back, be sure to let the engine idle with everything off so the ECU can learn the idle conditions of your new engine.

Then, for the ultimate test, immediately take it out to the woods for a camping trip the next weekend like I did lol (I at least made sure to drive it for the week prior to make sure it was good first)

oh hell yes, this is awesome documentation man! Thanks for putting it together and I will add it for sure!

Dropping my motor in this weekend, and you literally answered what i was pondering if i could grab the motor from the points on the 4 corners. Definitely gonna be alot easier to lift from there than the motor mounts.

y=mx+b said:

oh hell yes, this is awesome documentation man! Thanks for putting it together and I will add it for sure!

Click to expand...

daprotege5 said:

Dropping my motor in this weekend, and you literally answered what i was pondering if i could grab the motor from the points on the 4 corners. Definitely gonna be alot easier to lift from there than the motor mounts.

Click to expand...

Awesome man! Glad it's gonna be helpful!

Yeah, those 4 points are the most ideal spot IMO. I forgot to add this to the post about dropping it in, but be sure and check that all 4 holes are empty, cause for some reason, on the engine I bought, the front driver hole was filled in - not full of gasket maker, but aluminum, like the engine cast/mill process didn't make the hole. The top of the hole was there, but the bottom wasn't. Not sure if this is common, or just a fluke I happened to get though

To get around that, I just threaded the upper alternator bolt in and put the chain around the entire thing, like so

Interesting, is that honestly the only difference? Just went to a different VVTI Cam Phaser with a 3-pin connector? I thought there were a couple of other differences?

In any case, nice job! You can buy new connector housings for your cam sensors and just de-pin the old ones and swap them over. We have a bunch of old harnesses out of cars we'll strip for parts when connectors break. But if you look the connector over there's actually a number printed into the plastic that you can take to your dealership and they'll find the part number for just the connector itself.

BlackWorksInc said:

Interesting, is that honestly the only difference? Just went to a different VVTI Cam Phaser with a 3-pin connector? I thought there were a couple of other differences?

In any case, nice job! You can buy new connector housings for your cam sensors and just de-pin the old ones and swap them over. We have a bunch of old harnesses out of cars we'll strip for parts when connectors break. But if you look the connector over there's actually a number printed into the plastic that you can take to your dealership and they'll find the part number for just the connector itself.

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Yep, as far as I can tell, that was the only change between the older and newer model 1gr's. Well, at least the only "incompatible" changes for sure, because everything else I looked at had the same part numbers

Oh really? Cool! I didn't know that, I'll have to look for the number cause While the tape works, it's not exactly ideal

did the torque converter bolts line up for you??? my bolts arent reaching the holes as if i have to pull the converter up a bit. not sure if that was ok or possible??

Cancel that, put the freaking plate on backwards. Ahhhhh what a fun adventure.

daprotege5 said:

did the torque converter bolts line up for you??? my bolts arent reaching the holes as if i have to pull the converter up a bit. not sure if that was ok or possible??

Cancel that, put the freaking plate on backwards. Ahhhhh what a fun adventure.

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Ah dang! I know that feeling all too well (refer to the part about mine only not cranking cause I left the ecu unplugged) lol :laugh: Glad you got it figured out!

Is everything still running good? Might be trying this myself soon since my headgasket blew a second time

ARK_ginger said:

Is everything still running good? Might be trying this myself soon since my headgasket blew a second time

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Absolutely! Still runs perfect and I haven't had a single problem since the swap

If you decide to do it and have any questions, feel free to reach out!

[MENTION=409236]P_nlsn[/MENTION] Notice any increase in fuel mileage with the long tube headers or does it just breath better?

I'm also curious where you sourced the engine as well. $1200 seems like a good price.

ARK_ginger said:

[MENTION=409236]P_nlsn[/MENTION] Notice any increase in fuel mileage with the long tube headers or does it just breath better?

Click to expand...

It's hard to say because I added retarded exhaust cam gears, longtube headers, newer fuel injectors, and fixed a hadgasket leak all at once. I have definitely noticed an mpg increase, I just can't pinpoint exactly why/how much from each mod because I did so much at once.

ARK_ginger said:

I'm also curious where you sourced the engine as well. $1200 seems like a good price.

Click to expand...

I got it off a local guy on Facebook Marketplace. He was parting out his totaled 4runner and I think he was originally selling the Tranny and Engine together, but we talked to him and got him to sell them separate so we got the engine

P_nlsn said:

The old engine was pulled out of an 07 with 175k miles. The guy was selling it on Facebook marketplace because his son unfortunately rolled his 4runner into a ditch

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