Difference between 2006 Auto and Manual Engines (2.3L)

Search this forum for the 2.3 to 2.5 liter swap thread; the Ford Duratec is basically the same motor as the Mazda motor, but more powerful, more reliable, more available, and more affordable. FWIW, there is no difference in engines in AT cars vs. MT cars.

To be honest, this one is a flip. I have actually made a lot of money flipping Mazda3s and 6s, but never ran into this issue until now. Having said that, I am likely not going do anything other then return it to complete stock configuration. I already ordered an AT motor, with the expectation that the engines were basically the same, based on what I was able to find. What I wasnt able to find was exactly what the differences are so I am going in assuming that the AT motor will require the flex plate removed/flywheel installed and a pilot bearing installed. Is it safe to assume that my list is correct?

I was also under the longstanding impression that the 2.3 was a duratec as well.?

Yes, put on a flywheel and pilot bearing and you are good to go. Yes the 2.3 and 2.5 are in the same family, but the 2.3 has an unusually high failure rate not seen in the 2.5 or the 2.0 either. Also, since you are flipping cars, you would be far better off getting a Ford 2.5 for maybe $250-450 compared to double or triple that for a used 2.3.

I am definately aware of the failure rate of the 2.3... Its unfortunate because they are great cars with the exception of that terrible motor. I would also agree that the cost of a 2.5 makes the swap very attractive. This particular model has the AC compressor bolted to the bottom of the oil pan so I wonder how that would play into the available 2.5s to swap in.

Thanks for the info regarding the differnces in the respective engines (AT V Manual), that opens up some options for me in the future. Now I need to order a flywheel and clutch kit.

As part of the swap you have to swap the oil pans and the oil pick up tube, as well as a few other things.

I just did a 08 mazda3, 2.3 automatic engine, into a manual car. I exchanged the valve cover, vvt solenoid, timing cover and oil pan, replaced the flex plate, with the original flywheel, put a new pilot bearing in the back of the crank and then was told, the harmonic balancer is different from manual to automatic transmission, so I switched them... I did have to retime the engine, which isn't really a big deal, if you have the crank lock bolt... it started right away and no problems.

SO this seems to be somewhat contradictory to previous information. Not that I don't believe you. I had also noted somewhere that the harmonic balancer was a different PN, but I was assured these were drop in replacements.

I would say that the long blocks are pritty much the same, but there are several different oil pan options available... the 2.3 is a good engine, but these engines are all very dependent on oil, clearances are tight on the bearings, so if they ever run out of oil, it's game over...

There are LOTS of folks here who would argue with the assertion "...the 2.3 is a good engine...".

I'd say that you are spot on, but if you build the 2.5, then build a 2.3 you will see the differences between the two and that is what I can base my opinion on...
If I designed a engine, it would not be designed to use 20 weight oil!, but that is what these engine clearances are designed for...
In the shops I have worked with in the past, we called it, enginered failure! No doubt about it, the 2.5 is a less expensive option for replacement of the 2.3 duratec.

I would argue 0W-20 or 5W-20 oil has virtually nothing to do with the premature engine failures of the 2.3; Ford and others have been specifying xW-20 oils for over 20 years and there is virtually no evidence this oil causes premature engine wear. Then consider the 2.5, which is simply a reengineered 2.3, has proven to be a very durable engine regardless of the oil grade used.

I'm not interested in fighting about the subject, you have some experience with the engines that is different from what I can see...(in the engines)good luck in your future endeavors...
I've been building race engines for many years now, I can only attest, to what I see... I've built both engine's over the course of the past 15 years and had great results from both...

Spacerat said:

SO this seems to be somewhat contradictory to previous information. Not that I don't believe you. I had also noted somewhere that the harmonic balancer was a different PN, but I was assured these were drop in replacements.

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The engine is a drop in replacement in the sense that it will bolt up to the transmission and run with the factory pcm. You still have to swap parts around has there are several different applications that the engines are in and you need to put the parts on it for your application. If you want drop in replacement that requires nothing but taking the engine out and putting the replacement in, then you need to get the exact engine from the exact same application as your car. If this is a flip then that is probably not the best option because those engines are more expensive then a ford 2.5l with a little bit of extra elbow grease to make the swap work for your application.

SRND said:

I'm not interested in fighting about the subject, you have some experience with the engines that is different from what I can see...(in the engines)good luck in your future endeavors...
I've been building race engines for many years now, I can only attest, to what I see... I've built both engine's over the course of the past 15 years and had great results from both...

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Believe what you want, I follow the science and stand by my words, the 2.3 and 2.5 liter engines are very different when it comes to longevity.

SRND said:

I just did a 08 mazda3, 2.3 automatic engine, into a manual car. I exchanged the valve cover, vvt solenoid, timing cover and oil pan, replaced the flex plate, with the original flywheel, put a new pilot bearing in the back of the crank and then was told, the harmonic balancer is different from manual to automatic transmission, so I switched them... I did have to retime the engine, which isn't really a big deal, if you have the crank lock bolt... it started right away and no problems.

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So I took a look at your list and compared PNs. I did not see a difference in the VVT Solenoid, Timing cover and VVT Solenoid (not that I question your statement, I am just not sure what I would replace it with). I have a new Flywheel and clutch with Pilot bearing. I also have the Camshaft lock bar and timing pins, so I can source a harmonic balancer and retime. I checked the oil pan and its the right one, with the mounts in the pan for the AC compressor.

So I ordered a manual Crank Pully/Harmonic balancer, guess we will see where this goes. FWIW I have flipped many of these in my time and those 2.3s always seem to go down due to oil starvation. It either spins the mains or causes the cams to slip out of time.

Downermazda said:

The engine is a drop in replacement in the sense that it will bolt up to the transmission and run with the factory pcm. You still have to swap parts around has there are several different applications that the engines are in and you need to put the parts on it for your application. If you want drop in replacement that requires nothing but taking the engine out and putting the replacement in, then you need to get the exact engine from the exact same application as your car. If this is a flip then that is probably not the best option because those engines are more expensive then a ford 2.5l with a little bit of extra elbow grease to make the swap work for your application.

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I am all good with a little bit of work, doesnt bother me. I was just not able to find any list or how-to on what would need to be changed. I would have preferred to just purchase a manual motor, but there was none with 200 miles of here, whereas there were a metric crap ton of autos. So I have the motor and I am going forward.

shipo said:

I would argue 0W-20 or 5W-20 oil has virtually nothing to do with the premature engine failures of the 2.3; Ford and others have been specifying xW-20 oils for over 20 years and there is virtually no evidence this oil causes premature engine wear. Then consider the 2.5, which is simply a reengineered 2.3, has proven to be a very durable engine regardless of the oil grade used.

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I'd like to make one point here... if the engine runs out of oil, that is what I said! As far as 20 weight oil goes, I don't care for it. If you keep oil in any engine, at the correct amount, you can plan to get many miles out of the engine. Any engine that is run out of oil, will fail eventually! The clearances in a engine like the 2.3 liter will fail quicker, than an engine that can have a larger tolerance... I think you are arguing with yourself at this point!

Nah, I just like seeing someone make an argument and then move the goalposts when the argument falls short; well done.

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