Toyota 3.0 to 3.4 engine swap
Recipient vehicle is 1995 Toyota 4Runner 5 speed 4x4 Limited.
I decided to go with a 1999 model for my donor vehicle. The engine package came from a 1999 Tacoma 5 speed 4x4. Cost was $1600.00
Newly recovered overstuffed leather on all seats with seat and back heaters installed in both front seats. This is a comfortable setup. My wife likes it much better than her 2001 Honda Accord with leather. Seat heaters were $500.00 total installed for both seats. This is a great way to spend $500.00. Seat recover and extra foam was just over $900.00. Used surplus aircraft leather in Tan that just about matched the original interior color.
OME 1.5” lift rear springs
OME steering stabilizer
Factory 4.56:1 gearing
Tires 31 x 10.5 x R15
Future modifications plans include, an E-locker for the rear, probably a turbo of about 5 PSI. The turbo is not for more speed, rather for power. Have to see how I like the 3.4 by itself first. Currently have 31 x 10.5 x R15 tires. May go to 32” but don’t want the thing to get much higher. I would prefer the stock height but I do not want to cut into the hood.
My goal was to use as few special parts as possible. I did not want to have a parts headache in the future of having to get custom parts for repair. This is my personal ride and I do not intend to sell it.
I bought this Runner in November of 2005. It came with a blown head gasket among other things. I really wanted to swap the engine after I got it but needed the Runner for a cross country trip on Christmas 2005. So I had a local machine shop do a complete overhaul of the 3.0 for $2250.00. Since then I have put 15,000 on the 3.0. I put Downey ceramic headers and K&N drop in air filter on it thinking I would be happy with the performance gain. Also installed header back 2.25” i.d. exhaust with hi-flow cat and a Borla open muffler. During the trip, once I got into the mountains I was disappointed with the power even with the headers and all. Before the trip was over I was convinced that I would not be satisfied until it had much more power.
It will pay off to do your homework in the beginning before you by any parts. I checked with ORS and they said that 1998-1999 were the easiest year 3.4 to swap for electric and to maintain supercharger including 7th injector modification potential in the future. 2000 and later year 3.4 you run into the issue of having to drill a hole in the engine block to install the oil dipstick in the correct location to be compatible. Not a big deal but I did not want the headache. The 1999 has an extra hole already in the correct spot for relocating the oil dipstick, just remove the plug. I wanted to keep the option of TRD supercharger. More recently I have been attracted to the Tacoma turbo system marketed by Squires Turbo Systems. I can see this Runner having a turbo sometime late next year 2007.
Before I started I ordered and installed a 2” body lift kit from 4crawler .com. I had read in other’s reports on the swap that it was necessary to lift the body 2” or cut a hole in the hood. The problem area is that he front end of the intake plenum on the 3.4 will hit the hood. I could not stand the idea of ruining the clean lines of my Runner with a stupid hood scoop.
The kit from 4Crawler went in nicely in a few hours one evening. I used the upgraded stainless steel hardware. I had to do some trimming to get the stock front bumper to fit the way I liked it. Also had to adjust the steering rod length. I plan to put a .375 - .500” spacer in the steering for final use. Took about 4 hours to complete installation.
Shifter and transfer case selector
After lifting the body 2” the gear shifter would not go into 2nd, 4th, or reverse because it was hitting on the rubber boot. I installed a URD short throw shifter to lift the handle up 1” and reduce the shifter travel so it would not hit the boot. Used the kit that is for the 3.4 liter.
The transfer case shifts okay although it’s operation is stiff due to the lift. I plan to put a short throw shifter on it as well.
I decided to go with the Toyota factory exhaust from a 2002 3.4 vehicle. In year 2001 and later Toyota put factory tubular exhaust manifolds with matching tubular crossover on the 3.4 engine. The crossover actually has tubes in it that bring the exhaust over and dump it into the down pipe and not into the other manifold. So basically both sides of the engine exhaust remain separated until they dump into the exhaust down pipe. I kept the exhaust down pipe location the same as the stock 3.4. This meant it dropped down on the passenger side rather than on the driver side as the 3.0 does. Then I routed the pipe back to the driver side using 2.25” i.d. tubing to pick up the exhaust pipe just forward of the stock 3.0 cat O2 sensor location. I routed it under the drive shaft. It clears well and does not stick below the transmission mount/frame support. I stayed with the remaining exhaust system of 2.25” i.d. pipe, hi flow cat, and open Borla muffler as described below.
Reasoning: I had installed Downey headers on my 3.0 followed up with 2.25” i.d. “Y” pipes from the headers to 2.25” exhaust through a hi flow cat and open Borla muffler. Result was poor torque on low end and increased power all up on the high end. It would produce power from 75-95 MPH 3300-4300 RPM with 31” tires but was really wimpy in the low and mid. I wanted to get the power more in the low and mid range. I thought that the stock manifold would maintain back pressure at the engine for low to mid range then be able to flow better for some gains in high end due to improved flow of the tubular manifold, crossover, hi-flow cat and open muffler.
The first O2 sensor bung was already on the segment of 3.4 down pipe that I used. The first O2 sensor is almost in the stock 3.4 location. This makes it very easy to install the wiring harness for this location. It will plug in without having to add any extra length to the wires.
The 3.4 exhaust crossover dropped almost right on the passenger side frame. Just enough room to get the down pipe which is I welded to the stock 3.4 down pipe flange installed. I had to cut the down pipe off and weld up a transition tube to curve it away from the frame then reweld the down pipe back on in a new position. Also fabricated some heat shielding and welded it to the down pipe to help protect the brake lines in this area. I had cut the stock 3.4 down pipe off a few inches past the O2 sensor bung when I bought the engine package.
The factory tubular exhaust manifold is like a mini three into one tubular header which is then covered with a thick outer shell which appears to be stainless steel. I believe the shell is to protect the engine bay from heat. The matching tubular crossover is made the same way. Very smooth in the inner tube sections.
Oil dipstick and tube
On the 1999 it is only a matter of removing the hole plug located just under the left side engine mount and installing the 3.0 dipstick tube and dipstick. Use the oil dipstick adapter fitting from the 3.0. It can also be tapped out from the bottom side of the block then installed on the 3.4. The plug is only press fit into the block and can be tapped out from the bottom side once the oil pan is off.
Oil sending unit
The oil pressure sending unit needs to be removed from the 3.4 and the sending unit from the 3.0 needs to be installed in its place. Otherwise damage will occur in the form of burning out your dash mounted oil pressure gauge. It works very well and is compatable with the electrical plug already on the 3.4 engine harness. Just swap and plug it in.
I decided that in the essence of time I would use the ORS conversion harness. This is the place to spend the money IMO. Cost for harness $680.000 plus $15.00 S/H
I removed the large rubber grommet from the 3.0 engine harness and slipped it onto the 3.4 harness so it would seal the hole in the firewall. To get the grommet to slip over the large electrical connectors I had to make a slit in the narrow part that wraps around the wire harness. The cut can be completely closed with rubber tape, etc upon final installation giving a good weather seal that looks real nice too. I removed the 3.4 firewall seal fitting and tapped up the harness in this area to protect it.
I used the stock 3.4 battery/starter harness that came with the engine and it was long enough to reach the new battery location on the driver side of the engine bay.
The tachometer must be modified to read the RPM correctly. This is done by removing the gauge cluster and reworking the electronic board of the tachometer slightly. There are several posts some include pictures of what to do. See link for Pics. This is the mod I intend to use. I have not completed it at this time so can not report further about how it went. http://rides.webshots.com/photo/2124851480042310107gMlKlu
Used a 3.4 flywheel, pilot bearing, clutch disc, and clutch pressure plate. Used a 3.0 throw out bearing. If you use the flywheel bolts from a 3.0 manual transmission they must be cut down because they are too long by a little more than a quarter of an inch. Pilot bearing was the same for 3.4 or 3.0 I used the pilot bearing that came with the 3.4 clutch kit.
Used the 3.4 power steering pump and pulley with 3.4 stock drive belt. To attach the high pressure hose used the bolt from the 3.0 power steering pump and stock 3.0 power steering high pressure hose. Don’t forget the thin copper/aluminum seals that go on either side of the high pressure fitting.
Used the stock 3.0 compressor and lines. You do not even need to open the system and let out the freon when doing the swap. Used the compressor clutch and pulley from the 3.4 engine. Used the stock 3.4 compressor mounting bracket. It all bolts right up. Electrical connector on the 3.0 A/C compressor is compatible with the connector on the 3.4 engine wiring harness. No worries here. This way you do not have to buy the whole compressor from the donor vehicle only the clutch and pulley. Save a little money here and by not having in to reservice the freon. Use the stock 3.4 drive belt.
Heater hoses at the back of the engine
I used the stock 3.0 molded heater hoses on the 3.4. The long hose is not pretty on final installation but is very functional and durable. It looks like standard heater hose could be used also without problems if routed well. The bend is open enough that you could also use heater hose from the parts store if desired.
Used the stock 3.0 alternator with the 3.4 mounting bracket. No need to change the alternator drive pulley because they are the same belt style on both vehicles. Used the lower bolt from the 3.0 bracket to the alternator and tossed the 3.4 tensioning bolt setup. I bent by hand slightly the lower bracket to get it to the front side of the alternator. Also I cut off the end of the lower bracket just outboard of the slot to give better clearance for steering column.
Used the stock 3.0 starter. It will bolt directly up. Electrical connections on the 3.0 starter are compatible with the connections on the 3.4 engine wiring harness. No worries here. I did pry loose and rotate 180 degrees the starter trigger wire connection because the 3.4 wire harness did not permit it to bend around and plug in from the rear. With the tubular manifold installed access to the starter is great. Also no worries about heat damage to the starter like is present from headers.
Used the mounts from the 3.0 engine. They will bolt directly onto the 3.4 engine. 3.4 mounts are different and will not put the engine in the right place.
Used the stock 3.0 oil pan
Oil sump baffle
Used the stock 3.4 baffle. Required a small clearance trim and a hole cut to allow the 3.0 pick up tube to bolt to stock location. I liked the fit of the 3.4 baffle over the 3.0, either one fits though. Shaved the head on one baffle bolt to clear the pickup tube.
Oil pickup tube
Used the stock 3.0 oil pickup tube.
I cut the dipstick tube attach bracket loose relocated it so it would bolt to the engine head and rewelded it to the dipstick tube.
3.4 oil dipstick stock location at front of the engine. After you remove the 3.4 oil dipstick from the stock location at the front of the engine a hole is left. I tapped this hole with a 10mm x 1.25 tap and installed a flanged bolt about 1” long with silicon on the threads. The flange of the bolt made a perfect seal on top of the hole. Looks good. You can get flanged bolts from auto parts store. Don’t suggest lots of torque on this bolt.
Upper radiator hose
Used Gates P/N 22118. Fit is pretty good with no cutting.
Lower radiator hose
Fabricated one by cutting a hose and rotating it then reclamping it together with a 1.25” copper plumbing union and hose clamps. I used the stock 3.0 hose for the butcher job.
The Gates hose that I wanted and am pretty sure will fit perfect with no cutting was a special order item only and I guess I was not special enough to be able to order it. I will continue to try and find a perfect fit hose for future permanent installation. ORS.com offers a lower hose. I may break down and order theirs.
Fuel supply line
Fabricated a new steel line segment to run from the fuel filter to the engine to clear the exhaust and give additional length to meet the engine fuel flex line coming from the injector rails. Used 5/16” tube and used the stock 3.0 flange nuts which I removed from the old segment of fuel line.
Fuel return line
Used about 3 - 4’ of standard fuel line to route the return fuel from the left side of the engine along the firewall just below the heater valve to the hard line on the right side wheel well.
I installed a Walbro 190 lpm to support potential future upgrades. No changes should be required to the stock fuel pump normally. If you change it I would recommend soldering the wires over crimping. Just a personal preference so I do not have to worry about poor or failed connection in the future.
Used the 3.4 fan. Either fan will fit, I selected the 3.4 fan because it is slightly larger diameter and I felt this would provide a higher volume of air flow. If it does not come with your engine package it is just as easy to use the fan from the 3.0 and you don’t have money tied up in fan sitting on the shelf.
Used the 3.4 clutch. Again either 3.0 or 3.4 will work. The 3.4 looked cleaner (less rusty) so I picked it.
Brake vacuum booster hose
Removed the stock 3.0 booster line from the firewall. Then cut a piece from the stock 3.0 brake vacuum booster hose that fits perfect in the new installation. With the stock 3.0 hose removed this then leaves a handy location along the firewall to run a conduit in the place where the hose had been and use it for the new wiring changes to run in.
Used stock 3.4
Power steering belt
Used stock 3.4
Used 42” belt. Parts clerk said this is the stock size for an alternator bolt on a 1999 Tacoma.
Used the one from the 3.4 complete with the VSV’s. Fabricated brackets and mounted it on the left fender near the brake master cylinder booster assembly.
Evaporative pressure switch
Soft mounted the pressure switch to the neighboring hoses near the brake booster with rubber tape.
Clutch support bracket
Routed the cable left from the firewall pass through then forward and picked up the 3.4 cable support clip on the front of the manifold. Looks and works good.
Fuel vapor line
Routed the fuel tank vapor line from the hard line on the right fender around behind the engine follow the same routing as the fuel return line then on to the evaporative canister.
Intake air filter
For now I have part of a 97 4runner intake tube and an aftermarket filter clamped to the end of the MAF. Final plan is a performance intake of some type. Have not decided on a brand yet.
Black Pearl with 3.0 and no body lift
After 2" body lift and 3.4 swap completed
Sweet Oil filter access
Exhaust downpipe and #1 O2 sensor
Exhaust viewed from driver side
Exhaust Cat, #2 O2 sensor, Borla muffler
ECU with ORS harness 1
ECU with ORS harness 2
Brake booster line. Red conduit is where the stock 3.0 booster line had run along the firewall.
Evaporative canister 1
Evaporative canister 2
3.4 engine harness installed with 3.0 rubber firewall grommet
Ignitor bolted to existing holes near the main fuse box on passenger side fender.
3.4Engine right side upper
3.4 engine right side lower. sweet starter access. note the clean installation of the tubular factory manifold.
3.4 engine right side forward. power steering pump, ac compressor
3.4 engine left side forward. oil dipstick