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Discussion Starter · #1 ·
Hey there, so I just recently got a 1st gen ms3 and it either needs a rebuild or new engine. The previous owner ran out of oil when driving and now there’s knocking. I’m wondering if I should engine swap or just rebuild. And if I engine swap, what should I get? Or should I just rebuild. Let me know.
 

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I’ve got the ms3 2.3l turbo, where is the 2.5 engine from? I’ve heard that the cx7 has the same engine as the speed 3. Is that true? Sorry, I’m just learning about this stuff.
 

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@Jo James, I do not believe there is a 2.5 liter turbo which can easily be transplanted into a Speed3; I think your only options are the cars which carried the old 2.3 liter turbo which means the Speed3, Speed6, and the CX-7.
 

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@Jo James, I do not believe there is a 2.5 liter turbo which can easily be transplanted into a Speed3; I think your only options are the cars which carried the old 2.3 liter turbo which means the Speed3, Speed6, and the CX-7.
Ok, thanks, that’s what I thought.
 

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For enough money, many things are possible. Kind of a SWAG guess here, I'm thinking an easy six to eight grand to cover it.
 

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@Jo James, I do not believe there is a 2.5 liter turbo which can easily be transplanted into a Speed3; I think your only options are the cars which carried the old 2.3 liter turbo which means the Speed3, Speed6, and the CX-7.
Wrong. You can swap in a Ford Fusion (or Mazda for that matter) MZR 2.5 motor. You will have to fashion a new oil return line by tapping an A/N fitting into the oil pan. This is because the 2.3 turbo block has an oil return port on the back of the block but the 2.5 non-turbo motor lacks this. You also have to swap the heads since the turbo uses a different head than the non-turbo. Other than these issues it is very much like any other swap of the garbage 2.3 for the far superior 2.5
 

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Wrong. You can swap in a Ford Fusion (or Mazda for that matter) MZR 2.5 motor. You will have to fashion a new oil return line by tapping an A/N fitting into the oil pan. This is because the 2.3 turbo block has an oil return port on the back of the block but the 2.5 non-turbo motor lacks this. You also have to swap the heads since the turbo uses a different head than the non-turbo. Other than these issues it is very much like any other swap of the garbage 2.3 for the far superior 2.5
Wrong?!? Seriously? What you are proposing, while possible, is far-FAR from a simple drop in motor swap. If anything, it is your post which is wrong.
 

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Yes seriously. Nobody said anything about "simple drop in motor swap". In fact, the OP mentioned rebuilding his engine itself, which is far, far more complicated and expensive than what I proposed. A 2.5 motor swap can be done for well under $500, and if drilling a hole in the oil pan and installing a simple A/N fitting is too much for you, then that's fine. TO anybody contemplating an engine rebuild, the stuff I mentioned is relative child's play. And yes, I have done this conversion on a Mazdaspeed 6 which is much more difficult due to the AWD system it has. A Speed3 is simple in comparison.
 

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You're welcome to your opinion, but I have to disagree.
 

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You're welcome to your opinion, but I have to disagree.
Disagree all you want, that's your right, but the fact remains that you are completely wrong. I just checked car-part.com. Salvage turbo 3 engines go typically for over $3,000 and most of these have over 100,000 miles on them. In the typical speed3 installation, they are near end of life. Sorry but facts.

On the other hand, a used Ford Fusion 2.5 costs about $250 in my area, many with only 50,000 miles or less. Tapping the oil pan takes about an hour if you are taking your time, and the oil return fitting costs maybe $10. Swapping the heads might take a couple of hours, and there is the modest cost of the new head gasket. The hardest part is setting the timing, but there are great videos on youtube showing every step of this in great detail.

Swapping to a 2.5 easily saves about $2,500 in costs, and you get a stronger and more powerful engine as a result. Just because this is obviously far beyond your skillset does not make it a wrong answer for somebody else, especially since they are probably more skilled than you.
 

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Dude, you're talking about putting an engine not designed for a turbocharger into a car, changing the head and then turbocharging it; like it or don't, believe it or not, the engine will not last. And no, the 2.5 Duratec is not stronger than the 2.3 engine from the MazdaSpeed3.

Then there's the fact you dusted off a thread which is over a year old and essentially of no use to the OP.
 
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