2004 – 2008 Mazda 6 2.3L
Vehicle In This Guide:
2006 Mazda 6 / 2.3L engine / 5 speed manual / 96,000 miles
Update 3: More tweaks to the article. Added info on the intake camshaft & timing wheel/cog which seems to be causing some confusion.
Update 2: Added a FAQ sections for all the common questions about this swap. Also made some minor tweaks to the article.
Update 1: It has been over a year and 17,000 miles since the engine swap and the Fusion motor is still running great. I’ve added some more info to the guide – about timing covers, intake camshaft timing cog, and the cylinder head temp sensor.
Today we are going to show you how to swap your broken Mazda 2.3L engine with a cheaper and often times lower mileage Ford Fusion 2.3L engine. If you don’t know by now, the Mazda 6, the Ford Fusion, and the Mercury Milan have the same exact engine (with few minor differences). Why would you even want an engine from a Ford Fusion? Well, it’s about $1300 cheaper than the Mazda part.
The car in this article is a 2006 Mazda 6 with the 2.3L engine that has a rod knock. A search for the replacement engine turned up some interesting results – on average, a used 2.3L Mazda engine was around $2000 with over 100,000 miles on it. The same engine from the Fusion was priced between $700 – $1200, depending on the mileage. The engine that we are going to swap in this article came from a 2006 Ford Fusion, had 46,000 miles on it and cost $1,100. If you shop around you can land a great deal.
You may be wondering where to buy these engines. Obviously you can’t just run over to your local Napa or AutoZone for something like this. Your first and best option is to use www.ebay.com. You can check out photos of the engine, look at the sellers feedback, and contact them directly. Most of the time they will list “freight” as the shipping method, meaning that the engine has to be shipped somewhere that has a dock. If you’re a home mechanic, don’t worry, you can still contact the seller and ask if they can ship to a residential address. Some will agree to do this, especially if they are located within a few hours from you.
Your second option is to use www.car-part.com. Most auto salvage yards list all of their inventory on here so you have a lot of options. Unfortunately you can’t see any photos of the engine and you will have to call the yard and workout shipping and payment.
Ford Vs Mazda
Remember the part about a “few minor differences”? Here they are.
Ignition setup – In 2003 – 2004 the Mazda 6 had spark plugs, spark plug wires, and one ignition coil-pack that drove the four spark plugs. In 2005 the Mazda 6 used two versions of the ignition system, the old style spark plug wires plus one coil-pack and also a new individual coil-on-plug system. Note: these coils were the round style. In 2006 – 2008 the Mazda 6 2.3 exclusively used the coil-on-plug system and the coils were the square style. The Fusion 2.3 used the square style coil-on-plug system.
Intake Camshaft – While the actual intake camshafts looks very similar between the Mazda and Fusion 2.3, there is one very small but very important difference – the timing wheel/cog that is at the end of the camshaft. The 2003 – 2005 Mazda 6 had five teeth on the timing wheel/cog while the Fusion and 2006+ Mazda 6 had six teeth. Not only is the number of teeth different but so is the layout. Below you will see a photo of the Fusion timing wheel/cog. I have also included a layout diagram of the differences between the Fusion, the 03-05 and the 06+ Mazda 6 & Mazda 3.
Note #1: The timing wheel/cog is pressed on to the camshaft and is able to rotate if you put enough force on it.
Note #2: A couple of people in the comments section have found that the JDM Fusion 2.3 engines actually have five teeth on the timing wheel instead of six. In addition, they found that the timing wheel was clocked differently and as a result had to be rotated 1/8 of an inch counterclockwise. The air intake ports on the JDM engines are 1/4 inch taller and will not seal correctly with the stock intake gasket, leaving a small gap. Check out the comments by Steve Krause and Zane for all the details.
Oil Pan and Oil Pressure Sensor – The Mazda 03 – 05 2.3L engines had a tube for the oil dipstick on the side of the oil pan. The dipstick was routed to the outside of the engine. The later 06-08 Mazda engines routed the dipstick through the inside of the engine and out the top through the valve cover. All the Fusion & Milan 2.3L engines have the dipstick routed through the engine. The oil pressure sensors are different between the Fusion and the Mazda so they have to be swapped. Physically they look the same but they function differently. If you use the Fusion oil pressure sensor it will cause the oil light to come on.
Valve Cover – The early Mazda engines had metal valve covers. The later 06+ Mazda and Fusion 2.3 engines use a plastic cover with a hole for the oil dipstick.
Crankshaft Pulley and Crankshaft Position Sensor – The Mazda 2.3L and the Ford 2.3L have different crankshaft pulleys (number and layout of the timing teeth don’t match) and different crankshaft position sensors (one is three wire and the other one is two wire). The Mazda 6 2003 – 2005 also used a different crankshaft sensor than the Mazda 6 2006-2008 (sensors have different mounting points).
Front Timing Cover – Because of the different mounting points for the crankshaft position sensor, the front timing covers are different between the 03 – 05 and the 06+ Mazda 6 (See Brian’s comment at the bottom of the page). The Fusion uses the same timing timing cover as the later (06-08) Mazda engines. In addition the 03 – 05 timing cover has oil passages inside of it that are not present on the later 06+ Mazda and Fusion timing covers.
Cylinder Head Temperature sensor – The Ford version of the 2.3L has a cylinder head temperature sensor located on top of the engine.
What does this all mean? Basically, if you have the newer 06-08 Mazda 6 with the coil-on-plug setup then swapping to a Fusion engine is a breeze – the parts that you have to reuse from your old engine are the crankshaft pulley, crank position sensor, and oil pressure sensor. If you have an older 03 – 05 Mazda 6 then there is more work involved – you will have to reuse and swap your ignition system (spark plugs, wires, and coil pack), intake camshaft (because it has a different timing cog), crankshaft pulley, crankshaft position sensor, oil pressure sensor, front timing cover, and camshaft position sensor.
In all cases, when you are doing a 2.3L engine swap, you need to open the valve covers on both of the engines and inspect/compare the timing cogs on the intake camshafts. If the layout of the teeth on the cogs is different between the engines then you know that you will have to swap the intake cams.
You will want to reuse your Mazda wiring harness. It is also a good idea to stick with your Mazda intake manifold and the throttle body.
Frequently Asked Questions
What year of the Fusion engine can I use for the swap? – The Fusion used the 2.3 engine in years 2006 – 2009. Any of those will work. When searching for a Fusion engine you may see some places mentioning production date pre or post Dec 06. Either will work in this case. If in doubt, go for the newest engine that you can afford.
Will a Fusion engine from an automatic work with my manual car or vice versa? – It is the exact same engine with the exception that for manual cars there is a pilot bearing that is installed in the rear of the crankshaft. So if you have a manual Mazda and you got a Fusion engine from an automatic car you will need to install a pilot bearing. Don’t bother transferring over your old pilot bearing – it is a $10 part and should probably be replaced anyway.
I have a 2006 or up Mazda 6. Can I swap in an older (03 – 05) Mazda 2.3 engine? – In a nutshell, no. Older Mazda 2.3 engines have timing covers which contain oil passages. These oil passages are not present in the timing covers of newer (06 and up) Mazda 2.3 engines. See nojodas67’s comment for more details.
Will the Fusion 2.3 swap work on my Mazda 3 2.3 car? – It will but you will need to swap oil pans in addition to all the other items. Finally, the alternator will mount with only 3 bolts. See Joel’s comments for more details.
Will the Fusion 2.3 engine work in my turbo Mazdaspeed 3 or 6? – No. The Mazdaspeed engine has a totally different cylinder head to accommodate direct injection. The Fusion engine block lacks, among other things, machining for the turbo oil feed and return lines.
The car in this guide is a 2006 Mazda 6, which means that we have to reuse the Mazda crankshaft pulley and crankshaft position sensor. As far as engine swaps go, this is probably one of the easier swaps that you can do because there is so much room to work with. There are several ways of removing the engine from the car. You can drop the sub-frame and lower the engine from the bottom. Some people take off the front bumper and radiator and slide the engine forward. The last method is to use an engine hoist (crane) and lift it out. Personally, I hate working with the sub-frame and since I have an engine hoist, going from the top is my preferred method.
While this guide covers cars that are equipped with the manual transmission you can still follow along if you have an automatic. There are a few different steps that you have to take that will be covered in this guide.
Finally, there is more than one way to take out this engine – you do not have to do all of the steps in the order that is written here.
How to Swap the Mazda 2.3L with the Ford Fusion 2.3L – Removal
1. Put the front end of the car on jack stands.
2. Remove the bottom engine cover, aka under-body cover.
3. You will need to remove the hood. It’s held on with four bolts at the hinges. Its not that heavy and if you have long arms you can even take it out by yourself. Also remove the top plastic engine cover – it is snapped into place so just pull on it to remove it.
4. There is a lot going on in the photo below but its all fairly easy to remove.
- a – disconnect the MAF sensor.
- b – disconnect the variable air duct (VAD) control solenoid (green connector).
- c – disconnect the small vacuum hose from the air-box.
- d – disconnect thecrankcase vent tube at the valve cover that goes from the valve cover to the accordion.
- e – the air-box is also snapped into place at the bottom so all you have to do is loosen the clamp on the accordion tube and pull on the air-box to lift the whole thing out.
- f – finally, disconnect the battery cables. Remove the battery and the battery tray.
5. Later on you will have to unfasten the power-steering pump and the ac compressor so you need to remove the serpentine belt. Use a wrench on the tensioner and rotate it clockwise to create slack in the belt. The easiest way to get to the tensioner is from the bottom of the car through the wheel well.
6. Drain the coolant. On the bottom of the radiator there will be a drain hole. Turn counter clockwise and have something ready to catch the coolant. Remove the cap from the coolant over flow reservoir to help the coolant flow easier.
7. Okay, so you have the battery and air-box out of the way. Now it’s time to remove a bunch of hoses and tubes.
- blue – depress the locking ring and disconnect the brake booster vacuum supply tube from the intake manifold. You can also disconnect it from the firewall and rotate it around, leaving plugged into the intake.
- yellow – this is the fuel line. Held in place with a quick-disconnect. Make sure all the fuel pressure is relieved before removing this! You can relieve fuel pressure by taking out the fuel pump fuse and starting your car. This will use up all the remaining fuel in the lines. You can also just leave your car alone for a few days and the fuel pressure will decrease on its own.
- green – this is the evap tube. It has quick disconnects on both ends (one at the throttle body and the other one at the firewall). Remove the whole tube along with the purge solenoid valve (has the black plug – disconnect the cable from it first).
- cyan – small coolant line, disconnect from the radiator side and you can just leave this connected to the engine.
- red – coolant line. Provided that the coolant has been drained, remove this hose completely as it just gets in the way.
8. There are two wiring harnesses in the engine bay. The main harness which will stay with the engine as its lifted out and the secondary harness that is connected to the injectors and the transmission. This secondary harness stays with the car so you will have to disconnect a few connectors before moving it aside. Look below and disconnect the appropriate plugs on the harness.
9. A few more things to remove here.
- a – the shift cables are held in place with weak “paper clips”. Press back both sides and rotate the metal clip up. Then just pull up on the shift cable to disengage it.
- b – there are two bolts holding the shift cable bracket. Remove these and you can then move the shift cables (with the bracket) aside.
- c – two more plugs that you have to disconnect in order to free up the secondary harness. Also remove the bolt that secures the blue grounding cable.
If you have an automatic transmission you will have a selector lever cable instead of the shift cables. You will also have two lines for the transmission fluid that you will have to disconnect (have something ready to catch the fluid that leaks out).
10. You can see in the photo below that I have the shift cables out of the way. Couple more things do to:
- green – move the secondary harness out of the way.
- cyan – undo the clamps and disconnect the heater hoses. There will be some coolant left over in these so have a cup or something else to catch the fluid if you dont want to make a mess.
Mazda Fusion Engine Swap – Exhaust Manifold Removal
11. There are two bolts that secure the bottom of the exhaust manifold to the exhaust pipe. Remove the nuts on the bolts. Its a very good idea to spray these with rust penetrant first, let that soak in and then remove them.
12. Remove the the top heat shield from the exhaust. (5 bolts)
13. Now that the top heat shield is out of the way you can remove all of the nuts that are holding the exhaust manifold to the engine.
14. The final step is to remove the bolt for the exhaust manifold support bracket. You can then lift the manifold out of the engine. There is not a lot of clearance so you may have to take out the manifold at an angle.
15. Disconnect the main wire harness from the fuse box. There is a quick connector on the left and two nuts holding the cables on the right.
16. Now that the wiring harness is free, go ahead and move it over to the engine and out of the way. Your engine bay should now look like this. I have the heater hoses out of the way, all of the wiring harnesses out of the way, and finally the shift cables are out of the way. In this photo the fuel line and the brake booster tube are still connected – if you followed the above procedures, you should have removed these already.
17. You’ll want to remove the slave cylinder and move it aside. There are two bolts holding the bracket and two bolts holding the slave cylinder. Automatic transmissions do not have this part.
18. You will want to move the power steering pump out of the way. It is held by 3 bolts. Undo the bolts (you don’t have to remove them completely) and move the power steering pump aside. Use some wire or cable to secure it.
19. With the power steering pump out of the way you can now remove the coolant hose (green) from the thermostat housing.
Mazda Fusion Engine Swap – Removing The Axles From Transmission
20. Almost finished. You will want to remove the half shafts (axles) from the transmission. In order to do that you need to disconnect the tie rod and top control arm from the knuckle. This will allow you to swing the knuckle out and give you room to slide the axles back out of the transmission.
21. Use a crow bar and gently pry out the end of the axle. Once the axle is out you can move it aside and rest it on the sub-frame. The picture below is the driver side axle.
22. This is the passenger side axle. You will save some work if you can disconnect the axle (cyan) from the intermediate shaft. If you can’t, remove the two bolts that secure the intermediate shaft (green) and take that out of the transmission.
23. Technically you don’t have to do this step with the engine in the car but since we want to create plenty of room, the alternator is coming off. Its held on by three bolts. You will have to disconnect the electrical plug as well.
24. Remove the A/C compressor from the engine. It is held on by three bolts (one not shown in the photo). You do not have to disconnect any line, just set it aside.
At this point all the essential items have been removed / disconnected. The only thing left to do is to remove all of the mounts that are holding the engine and transmission. If you want even more room, you can remove the intake manifold (which I did as you can see in the following photos).
25. Let’s get this engine out. You’ll want to disconnect the torque strut. Either remove the bolts on the strut (cyan) or the two bolts that secure the bracket (green).
26. Remove the bolt from the front engine mount.
27. Remove the transmission mount. There are two bolts and two nuts holding everything together (one nut not shown). Before you do this, make sure the engine is hooked up to and supported by a hoist otherwise it will drop.
28. You can now slowly lift up the engine at an angle.
This is what you are left with. I highly suggest covering up the exhaust, and all the lines at the firewall. I would also cover up the splines on the half shafts, just to prevent them from getting damaged during re-installation. Use something like an old cable to secure the power steering pump and the A/C compressor.
Mazda Fusion Engine Swap – Transferring parts from the old engine to the new engine.
1. Remove the Mazda crankshaft pulley from your old engine. If you have an impact that can get the bolt off, great. If not, then you can make your own breaker bar using a couple of pipes from Home Depot. Use a flywheel holder tool or wedge something in the flywheel to keep the crankshaft from moving as you loosen the crankshaft bolt. I know the home made breaker bar looks ridiculous but trust me, it is very effective.
2. Before you can remove the crankshaft pulley from the Fusion engine and replace it with the Mazda part you have to line up the crankshaft and the camshafts correctly. In case you did not know, the crank pulley on this engine is not keyed so if you end up taking the pulley off, you will need some tools to keep the crankshaft and camshafts in the correct positions. The tools consist of a timing peg, a camshaft alignment plate, and a M6x1x50 bolt.
3. The first step is to remove the Fusion pulley. On the engine, locate a small bolt on the back of the engine. This is where the timing peg is installed. Remove this bolt.
4. Using the crankshaft bolt, rotate crankshaft clockwise until the number 1 cylinder is in the top dead center position. There is a small hole in the crankshaft pulley and when it is in the 6 o’clock position, you have your top dead center. At this point, install the timing peg. If everything is done correctly you should not be able to rotate the crankshaft in the clockwise direction with the timing peg installed.
5. Install the M6x1x50 bolt through the small hole in the crankshaft pulley.
At TDC, the camshaft slots should should both be horizontal. Allowing you to install the camshaft alignment plate.
6. Install the plate and it will keep the camshaft in place as you remove the crankshaft pulley.
You can now remove the Fusion pulley. You will have to keep the crankshaft from spinning – do not rely on the timing tools to hold everything in place. They are not designed to withstand the torque that is required to loosen the crankshaft bolt. You can wedge something in the flywheel to keep the crankshaft from spinning or buy or make a flywheel holder tool.
Once you have the Fusion crankshaft pulley off, install the Mazda pulley, use a new bolt and washer,and tighten to 74 lb-ft + an additional 90 degrees. Again use something to keep the crankshaft from spinning – do not rely on the timing tools. Remove all the timing tools. Rotate the crankshaft 1 and 3/4 turns and reinstall the camshaft plate and timing peg. Try to install the M6x1x50 bolt – if you can install it that means timing is correct. If you cannot install the bolt then you will have to redo the procedure.
If you have an older 2003 – 2005 Mazda 6 you will need to transfer additional parts as discussed in the beginning of the guide.
1. Lower the engine in the engine bay and tighten:
- Front engine mount bolt – 85 lb-ft.
- Transmission mount nuts and bolt – 46 lb-ft.
- Torque strut bolts – 66 lb-ft.
2. Install intake manifold (if removed).
3. Install the A/C compressor and tighten to 18 lb-ft.
4. Hook up the coolant hose to the thermostat housing.
5. Install the power steering pump and torque the bolts to 18 lb-ft.
6. Install the alternator and tighten the bolts to 35 lb-ft.
7. Install the slave cylinder and bracket. Torque to 16 lb-ft.
8. Install the rest of the coolant hoses.
9. Install the shift cables and bracket.
10. Install exhaust manifold. Tighten the exhaust manifold to cylinder head nuts to 41 lb-ft. in a cross pattern (in two stages). Tighten the two exhaust pipe to manifold nuts to 30 lb-ft. Tighten the bracket to 15 lb-ft. Tighten the heat shield bolts to 89 lb-in.
11. Hook up all the wiring harnesses.
12. Hook up the rest of the tubes and hoses.
13. Install the axles.
14. Connect the upper control arm and the tie rod to the steering knuckle. Tighten both nuts to 35 lb-ft.
15. Install the battery tray and battery.
16. Install the air cleaner assembly.
17. Make sure you filled up all the fluids and start it up. The end.
After everything was swapped over I took the car out for a test drive and noticed that the engine wanted to stall when the car was stopped. I had to keep my foot on the accelerator pedal to keep the rpms up. After driving for a few mile the problem went away and the engine idled correctly. My guess is that the throttle body was re-learning.
You may be wondering what to do with the cylinder head temperature sensor that is installed on top of the Fusion engine. You don’t do anything with it. The Mazda harness does not have an electrical connection for it. Just leave it in place and cover up the opening in the valve cover with the Mazda rubber cap.