2.3 to 2.0 swap

I know this is an old thread but I am going to start the same swap with a 2008 2.0l as 2.3l are too expensive and problematic so your lucky to find one. The 2006 through 2011 2.0l are VVT so I hope this will be straight forwards swap I will provide information here on how it goes as I am sure more will be faced with this problem. My 3 is a 2007 3 2.3l S grand touring model 5spd manual and the donor motor is 2008 3 GX 2.0l 5spd.
 
Hi all, just subscribed, I just bough a 2004 Mazda 3 Sport 2.3L Manual, the engine got 282k km and probably just spun a spme cank bearing, it was consuming oil and the previous owner waited 2 liter and the oil pump miss some oil in a quick turn (The car drive but tick like a time bomb on idle and more on small rev just to move it.) I want to do the 2.0L swap in the next month.

As I read on another forum, no need to reprogram the key if i keep the 2.3L ECU, cluster and oem keys already in the car. So i can just swap to the 2.0 Engine and like you pointed keep the 2.3 coilpacks and TB ?

also I got a better deal on a 06-07-08 2.0 Engine, same price as the 04-05 2.0 Engine but the donor car have 50k km instead of 104k km.... According to wikipedia it's the same engine, but maybe some sensors and connector placement are different ?

EDIT: just read 04-05 have no VVT, but 2.3L have it so still unsure if i can get the 06-09 2.0L and be direct swap with the 2.3L ECU etc....

Also heard of hamonic balancer been different on 2.0L AT and Manual and this can't be swapped, is it true and will an AT engine suffer been transfered to the flyheel on the Manual 5 speed 2.3L tranny ?

Last question is does the AC compresssor of the 2.3L (already in the car) can be transfered to the 2.0 engine without disconnecting the AC line during the swap or do I absolutely need the 2.0 AC compressor...

also it's the same 5 speed transmission for the 2.0 and 2.3L ?

Thanks in advance, my first Mazda, I usually work on Toyota (Previa, Supra MKIV, MR2 and Echo) !


im almost done the swap 06 to 09 has VVT so it almost a direct swap except you have to use your intake manifold from the 2.3 since the air valve solenoids on the 2.0 are on the side of the engine and not on the intake manifold. I don't have a donor car and doing this without ecu guage cluster and keys engine wiring harness, so tomorrow it will be ready to start if all goes well. the ac unfortunately needs to be disconnected. the 2.3 ac is exact for both motors. as for the harmonic balancer get a manual or auto engine "DO NOT REMOVE IT" they differ the flywheel is the same though unless you have to and have the proper tools to set top dead center and set your cams to 0 since the crankshaft sprocket is not keyed so it would cause lots of valve and piston damage if you were to just to swap the harmonic balancer without setting your crank and cams. the transmission are identical for the 2.0 and 2.3 of same years. I bought a manual 2.0 08 complete engine, no engine harness I used the 2.3 engine harness and changed the sensors that dint have the right plug and there were all plug and play same bolt patterns different end plug so they can easily be exchanged. I got a few hours work to see if this is a direct swap. I took the engine out from the front I only have hand tools. i left the bottom trans axel mount on the tranny to facilitate installation of motor and tranny i got lots of pics. the throttle bodies are identical in diameter and everything so i kept the 2.0 tb with my 2.3 intake manifold. this is a late post but i threw a rod at 92k bought the car had 68 and never left it alone so it was not neglect it got more oil and tranny oil changes and tlc in 6 months ever since 2007 when it was originally bought. My car is a 07 3 GT 5spd 2.3, swap engine is 08 3 gx 5spd 2.0. i may add i kept the 2.0 coil packs as they are identical to the 07 2.3. for some reason the mount on the block to the exhaust dint line up just slightly so i left it out it should not cause problems as the rest of the exhaust is on rubber hangers.
 
just need to ask this....

Is this swap purely out of functionality of getting it back on the road for the least amount of money?
 
just need to ask this....

Is this swap purely out of functionality of getting it back on the road for the least amount of money?

Exactly and 4 times less money for a better engine that will last logner than the 2.3 ans is more solid.


So I did my swap this week-end on my 2004 2.3 S MAzda 3, removed the powertrain friday, removed the driver side cv axle and dropped the powettrain from udner the car.

I had to buy a 2.0 belt as the 2.3 is longer. Could transfert the harness and all accessories, but the 2 vsv fromt he 2.3 had to come to the 2.0.

Had to use the 2.0 intake manifold as the 2.3 is logner and wouldn't fit, exhaust manifold are identical and was left in the car.

kept the 2.0 crank pulley as it was from a manual donor car.

the only sensor unused was the 2.3 oil pressure sensor for the Variable timing on the 2.3 valve cover.

I kept the 2.0 injectors, but sued 2.3 coilpacks and 2.3 throttle body

The car crank fine, got no checke ngine light or stored codes, the exhaust and spark plug smell fuel, but I got no spark.

So probably the Crank sensor or the cam sensor doesn't detect rotation and prevent to fire the coilpacks

Tired, put 20 hours in the swap from friday to a few hours ago and it won't start

Last test was, I swapped the CPS from the 2.3 engine to no avail.

The 2.0 engien was from a manual donor car as my 2004 MAzda 3 Sport with the broken 2.3L (282k km)

I used the 2.0 Crank Pulley as I measured and it appeared dientical to the 2.3 been both manual cars, but maybe the trigger wheel is different or it's timed differentely so the CPS read bad ? I read we need to retime the engien while removing the crank pulley as there is no notch in it like Toyota !

Any idea ?
 
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I called Mazda and asked the aprt manager directly, he looked with both my 2.3 Manuel Chasis and engine VIN and the replacement 2.0 Manual engine and both crank harmonic balancer part number are different DOH

So would like some confirmations before I start to swap both harmonic balancer and set the timing with the engine in the car...

My idea would be to to set b oth endine to TDC on no1 and lock the balancer in place using a 6mm bolt then grind a mark to be sure it doesn't move then swap both keeping them at the mark
 
New tests:

- all 4 coilpacks get 12V with the key at on position.
- the check engine light get on with the key at on, while cranking it stay on then blink 7 times.
- I readjusted the CKP twice using the 6 by 1mm bolt in the harmonic balancer, also did it on the old engine to compare, both was in the middle of notch 9 .
- While cranking the engine read 50-100rpm to 0 on the tach
- I'm waiting on ym Massive Absolute PRecision timing kit to swap the 2.3 Harmonic Balancer on my 2.0, but taking all emasurement I could and counting the notch they apepar to be the same, although Mazda confirmed they AREN'T the same part number, but peoples have confirmed keeping the Manual harmonic balancer included with the 2.0 Engine for the swap, while some having a different transmission and donor engine had to swap it keeping the old 2.3 harmonic balancer...

So the balancer is my only clue so far, maybe the CKP ring on it would be a bit off and throw the RPM and timing signal off so the ECM sence there is something wrong and retain spark to prevent engine damage...

Any more hints !?!
 
New tests:

- all 4 coilpacks get 12V with the key at on position.
- the check engine light get on with the key at on, while cranking it stay on then blink 7 times.
- I readjusted the CKP twice using the 6 by 1mm bolt in the harmonic balancer, also did it on the old engine to compare, both was in the middle of notch 9 .
- While cranking the engine read 50-100rpm to 0 on the tach
- I'm waiting on ym Massive Absolute PRecision timing kit to swap the 2.3 Harmonic Balancer on my 2.0, but taking all emasurement I could and counting the notch they apepar to be the same, although Mazda confirmed they AREN'T the same part number, but peoples have confirmed keeping the Manual harmonic balancer included with the 2.0 Engine for the swap, while some having a different transmission and donor engine had to swap it keeping the old 2.3 harmonic balancer...

So the balancer is my only clue so far, maybe the CKP ring on it would be a bit off and throw the RPM and timing signal off so the ECM sence there is something wrong and retain spark to prevent engine damage...

Any more hints !?!

So what's up with it???? I just bought a 3 from a client at work that have a bad 2.3 and I want to put a 2.0 too in it
 
So what's up with it???? I just bought a 3 from a client at work that have a bad 2.3 and I want to put a 2.0 too in it

So far not much the Car still doesn't run, it crank fuel but no spark.

I swapped the harmonic balancer from the 2.3 to the 2.0, they looked identical (diameter and number of teeths) but their part number was different.

I also checked the timing again using the Ford/Mazda Timing tools I ahd to buy to swap the harmonic balancer.

I checked compression and the motor is really clean inside the valve cover.

Still same stymptom, hear fuel pump, crank, fuel, no spark and no CEL, but if I crank for 10 sec. CEL will blink 7 times.

I checked the plugs, coilpacks get 12volts throttle body get power, battery fully charged

Next try will be to get the 2.0 ECU and key reprogrammed for it and give it a try before car go to storage for 6 more month or I part it out
 
So far not much the Car still doesn't run, it crank fuel but no spark.

I swapped the harmonic balancer from the 2.3 to the 2.0, they looked identical (diameter and number of teeths) but their part number was different.

I also checked the timing again using the Ford/Mazda Timing tools I ahd to buy to swap the harmonic balancer.

I checked compression and the motor is really clean inside the valve cover.

Still same stymptom, hear fuel pump, crank, fuel, no spark and no CEL, but if I crank for 10 sec. CEL will blink 7 times.

I checked the plugs, coilpacks get 12volts throttle body get power, battery fully charged

Next try will be to get the 2.0 ECU and key reprogrammed for it and give it a try before car go to storage for 6 more month or I part it out
Is it running yet? What did you find out?
 
I have an 2.3 07 manual Mazda 5 and i put a 2.0 08 automatic Mazda 3 engine in it, everything has been put together properly, the car wont crank, im only getting fire on 2 cylinders, other 2 are dead, i kept the 2.3 computer and wiring harness and throttle body, So the problem is that my 2.3 computer is not giving all 4 cylinders a signal to fire, so im thinking to haul it to the Mazda dealership and let them reflash the computer to run that 2.0 motor, anyone else ever tried this? It should work right?
 
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