Gen 1 Motor into Gen 2 Car Questions

[Mazda]

Hello everyone,
I am writing from a shop in South Carolina. We recently installed a replacement motor for a customer into a 2013 Mazda 3 Speed 3. The motor was purchased from JDM. This is our first Speed 3 swap and we do not claim to be experts on these particular cars/models. This is a general auto repair facility.

While we were doing the swap, we noticed that there were a few things different about this motor from the other motor. First of all, it had a cartridge, rather than a spin on filter. Second of all, it had a different, non-red oil filler cap. Third, there was a plate on the oil pan for the motor that we were installing, whereas the motor that we took out did not have that plate. After looking at a few threads on this forum, I came to the conclusion that the motor that we swapped into this car was a GEN 1 Speed 3 motor. Our car is apparently a GEN 2 Speed 3.

Now, the vehicle cranks up and runs well, but it has some drivability issues. First of all, it kind of stutters sometimes on hard acceleration, like an ignition misfire might be present. Additionally, sometimes, it feels like somebody cuts a switch under hard acceleration/boost and the vehicle bogs down in the middle of a pull. In the parts catalogue, the coils from GEN 1 motors to GEN 2 motors seem to have different part numbers. However, they looked the same and plugged up ok, so we tried them in this new motor, but there was not a change in the way it was running. Customer himself swapped the plugs after we did the replacement of the motor, but that didn't help.

This car has a lot of aftermarket parts on it that the customer got us to swap from his old motor.

This car has had some tuning done on the PCM.

This car has a few cheap, aftermarket parts on it.

And now, I seem to have figured out, this motor is a GEN 1, while the car is GEN 2.

I am not asking anyone to help me figure out the root of the problem, but I am hoping that someone on here might offer some guidance as to whether a GEN 1 motor will work OK in a GEN 2 car. JDM says that I shouldn't have a problem with it, but I am perhaps a little skeptical. I have seen some other threads that say the PCM is not interchangeable between generations. Could this be the root of my problems? Should I then source a GEN 1 PCM for this 2013 car? Can a used PCM be programmed on these cars? Will it plug up ok into the GEN 2 harness?

The only code present is a p0139 02 slow response code. Sometimes, when this problem is occurring, the traction light will flash at you, though you are clearly not losing traction. No code stored in the ABS module though.

It looked like you all were the experts on these cars, so I would appreciate any advice that you might be able to offer on this subject.
Thank you for your time and have a nice Holiday!
Josh

 

[Easter Bunny]

The gen 1 motor will work fine in the gen 2. Use all of the gen 2 computers. ECU PCM etc.

The spin on oil filter can be swapped over. The gen 2 valve cover should be swapped over as it is a better design and helps with crankcase ventilation.

Your issue might be more that a lot of the JDM motors actually come from cx-7s which used the same motor as gen 1 with a smaller turbo and are typically poorly maintained or even abused.

 

[Mazda]

Thank you very much for this reply. This is very helpful to me. I have now looked at threads comparing the CX7 582 turbo vs. the 882 speed 3 turbo, so I am now aware of this difference. Are there any visually distinguishable ways in which I can tell whether JDM gave me a Gen 1 Speed 3 Engine or a CX7 Engine without pulling the turbos off to look at the port sizes? Were there any other visual, external differences between the Gen 1 CX7 motors and the Speed 3 motors?

Finally, if I take this up with JDM next week, trying to find an authentic, Speed 3 Mazda Gen 2 motor for the customer, are there any distinguishing marks that I could mention to JDM? The solid oil pan vs. the oil pan with the access port near the harmonic balancer I take to be a Gen 1 vs. Gen 2 thing, but I am now worried that that may not be enough of a distinguishing mark, if the second gen CX7 engine also used a solid oil pan. Any advice here would be appreciated. Thank you so much for your time!

EDIT:

Thread 'How to tell if Gen1 or Gen2 MS3 engine?'

Feb 19, 2020

Buying my old MS6 back, but it now has an MS3 engine in it. Is there any easy way to tell if the engine is from a Gen 1 or Gen 2 MS3?

• NeverEnough
• Replies: 5
• Forum: Mazdaspeed 3 General Discussion

The thread above answered many of the questions that I have. I feel confident now in distinguishing between Speed 3 Gen 1 vs Speed 3 Gen 2 motors. However, a question remains: how to distinguish gen 2 Speed 3 motors from gen 2 CX7 motors (with smaller turbos), provided that there was a Gen 2 CX 7 motor? Did the Gen 2 CX 7 receive the modified (non flat) piston tops? If not, I am sure that would be a distinguishing feature...

 

[Easter Bunny]

Cx7 only had gen 1 motors. There is no difference other than turbo. You just need to swap the turbo. The motors are the same they gave you what you asked for. Your issue is that there are leaks in the intake tract

 

[Awafrican]

what mods got swapped on? have you guys done a boost leak test?

which engines I injectors and hpfp are you using? if your customers car had an after market intake he should have upgraded the hpfp internals so those need to used. prv might be worth testing with the engine hot koeo hpfp pressure should climb to 1850psi after shutting the engine off




as EB said no issues putting the gen1 engine in the gen2, quite common just use all the gen2 accessories and ECU, customers ECU should be tuned for his mods but maybe it's not tuned well.

the Gen 2 valve cover is the superior design and I would want it swapped it over on my car, oil caps are different threaded between the two.

coil packs are the same I think there was just a PN change, plugs should be gapped .026-.028" (up to .032" but preferred is range listed first)

 

[Mazda]

Thanks to everyone for your help. In the end, I got the customer the correct, Gen 2 motor. We sent the Gen 1 back to JDM for a refund. We got rid of the tune and tuned parts. Vehicle runs well. It is not clear what was causing the drivability problems with the first motor, but once I realized that there were differences in the Gen 1 and Gen 2 motors, I wanted to make it right for the customer. Merry Christmas and Happy New Year to everyone. I appreciate your help!