2007 Mazda3 2.3L I just swapped in a 2010 2.5L

[msowsun]

I was running synthetic oil in my 2007 Mazda3 GT 5 speed and changing every 10,000km. At approx 175,000km I started hearing a slight tapping/knocking sound at certain RPM's. I checked the oil and found it DRY!

I put in about 3 litres to bring it up, but the noise didn't go away. It was only audible over 2500 rpm when "floating", and went away under load or deceleration.

It gradually got worse over two months and 3 different mechanics said it was rod bearing noise. I started looking for a used 2.3 engine but found they are EXPENSIVE and hard to find. Especially with a Manual transmission. (I have since found out it doesn't really have to be from a MT car)

The ones I found were between $1,700 and $2,000. They are expensive just because of Supply and Demand. So many have gone bad that it is hard to find replacements and they ask a premium just because they can. I asked around about installing a 2.5 instead but everyone said it was too much trouble.

I found this Kijiji ad and now have a 2010 2.5L in my 2007 Mazda3. http://www.kijiji.ca/b-ontario/engin...004-09/k0l9004



They are in Quebec just north of Montreal. (6 hour drive from Toronto) It is probably no coincidence that they are located very near to LKG: https://www.lkqonline.com/#/

The guys' name is Burt and he speaks good English. His Mechanic is Sylvan and speaks very little English.

They will install a 2.0L for $1,250 cash or a 2.5L for $1,750 cash. (no tax) He said the 2.5L is actually $1,250 plus $500 labour. $250 extra if you want a new clutch. They do one almost every day and are VERY good at it.

I brought the car to him at 8am and they promised to have it done by 5pm. The shop is in a big double garage in a private home and there is no waiting room at all. There are a few Motels around but I couldn't find one that spoke English, so I rented a car for the day from Discount for $25.99 so I could drive around. At 2:30pm Burt called and said the car was ready.

I am very happy because I saved about $1,000 and should have a more reliable engine this time.

[RTEnthusiast]

Sounds cool Burt!

[midnightfxgt]

The ones I found were between $1,700 and $2,000.... It is probably no coincidence that they are located very near to LKG: https://www.lkqonline.com/#/

I am surprised you didnt check out LKQ. They are $1150 - $1450 for a 2.3L.

His price seems solid, so long as its good work

[74sickness]

I got a 2.3 for my gt for 1200 with 60,000 km on it and installed it myself. But if it starts knocking again I'll try this

[baymoe]

Do share some pictures of the engine bay!

[msowsun]

I got a 2.3 for my gt for 1200 with 60,000 km on it and installed it myself. But if it starts knocking again I'll try this

The engine bay looks exactly the same as it did before. No change.

[msowsun]

Oops. Wrong quote.

[a_ahmed]

welcome to the club i was the first to do this a while ago in canada with some help from miata guys.

The 2.3 engine is trash and yes older but more expensive. I went through two until i did some research and found out these engines burn oil and die in an explosive fashion. Rod bearing on cylinder 3 seems to be the usual culprit.

I went with a 2010 fusion motor.

I am doing the same thing now again. Different story but engine got flooded, unrelated to engine itself, so I am going to be on fourth frickin engine...

2.5 is descent...

[nepal1344]

I did this swap in a weekend on my own. It's really an easy swap. A buddy of mine wrote a how to on this swap when we did it to his 06 hatch. I picked up my 2.5L from a 2010 fusion 45,000kms from a wrecker in Niagara for $550. Picked up my 6spd for $300 from a member here. If anyone wants to do this swap and has questions feel free to message me.

[a_ahmed]

Did you get to get the intake to work, when i first did it 2 years ago, we were unable to get the intake to work, engine wouldn't fire up. We had to reuse the 2.3 intake. I was just fed up and wanted a car to drive. If you could please answer me in my tranny thread about the 6speed @nepal1344 my concern is the linkage, even though it bolts all up, what about the linkage and shifter? Doesn't make sense to me that would 'work' without something else from the 2nd gen? Just if you can clarify.

[marchz24]

Congrats on the swap... I like the idea...
Will the swap be a problem when it comes to doing your emissions test?

[msowsun]

Did you get to get the intake to work, when i first did it 2 years ago, we were unable to get the intake to work, engine wouldn't fire up. We had to reuse the 2.3 intake. I was just fed up and wanted a car to drive. If you could please answer me in my tranny thread about the 6speed @nepal1344 my concern is the linkage, even though it bolts all up, what about the linkage and shifter? Doesn't make sense to me that would 'work' without something else from the 2nd gen? Just if you can clarify.

I didn't do any of the work myself. When I dropped off the car there was a 2.5L "long block" sitting on the floor with nothing mounted on it. I assume the intake manifold everything else was just transplanted from the 2.3L engine.

[msowsun]

Congrats on the swap... I like the idea...
Will the swap be a problem when it comes to doing your emissions test?

I don't see any problems with emission tests. The fuel injection system, exhaust, and all electronic controls came off the 2.3L engine. I am pretty sure the car still thinks it has a 2.3L only now it is just slightly "healthier" and breathes a little better. (just like on a cold day, or when the atmospheric pressure is higher than normal)

[msowsun]

Do share some pictures of the engine bay!

The engine bay looks exactly the same as it did before. No change.

I finally got around to taking some photos of the engine bay. The only visible difference is the "10 Mazda 3 2.5 6 speed" written on top of the engine identifying it as coming from a 2010 Mazda 3 with a 6-speed transmission. (I kept my original 5 speed)

[baymoe]

Nice! I can't wait to get rid of my 2.3

[baymoe]

Came back from a road trip to Sault Ste Marie to Chicago them back to Toronto. Could not even go the distance of a tank of gas without stopping partway to fill a liter of engine oil. May need a new engine sooner than planned.

[Kiewan]

Do you know if they can replace a 2.0L with a 2.5L? Looks cool.

[msowsun]

Do you know if they can replace a 2.0L with a 2.5L? Looks cool.

They should be able to because they all share the same block.

[Kiewan]

They should be able to because they all share the same block.

Good find. Might check this out in the future

[nepal1344]

Do you know if they can replace a 2.0L with a 2.5L? Looks cool.

thats the swap i just did in the spring to my 08 2.0 sedan. you need to have it tuned though. It doesn't run well on the 2.0 settings.

[kiloaway]

My 07 Mazda 3 GT starts tapping/knocking now. brought the car to Jimmy and was told it's a known issue. I will top up 5w-30 and see how long it would last. I always replace the engine oil on time. only 150K km on it and never thought it would be gone this fast.

[bbell1984]

This is a great find. Out of curiosity whats the usual reason for the burning oil? I'm at about 240k and I noticed mine starting to burn oil roughly 20k ago.(2.3L 07, manual).

[baymoe]

No one has found the cause. People speculate it's the rear main seals, worn piston rings, through the pcv, and maybe others. The 2.3L is plagued with engine failure.

In my case, pistons 1, 3, and 4 are soaked in oil and can be seen through the spark plug holes. Car has 190k and require a quart of oil every 250-300km of driving.

Picked up a used 2010 Mazda3 2.5L engine with 55k. Can't wait to bring new life to the ride!

[Flagrum_3]

No one has found the cause. People speculate it's the rear main seals, worn piston rings, through the pcv, and maybe others. The 2.3L is plagued with engine failure.

In my case, pistons 1, 3, and 4 are soaked in oil and can be seen through the spark plug holes. Car has 190k and require a quart of oil every 250-300km of driving.

Picked up a used 2010 Mazda3 2.5L engine with 55k. Can't wait to bring new life to the ride!

If the pistons or combustion chambers are 'soaked' in oil, there is only really one thing that can cause it, and that's the valve seals. I'll bet since all the other speculations mentioned could be quite noticeable or would give obvious signs such as oil everywhere, or lots of blue smoke out the tailpipe, that the seals are the culprit.

Just curious, you guys with 2.3s burning lots of oil, ever get your valves adjusted?


_3

[baymoe]

If the pistons or combustion chambers are 'soaked' in oil, there is only really one thing that can cause it, and that's the valve seals. I'll bet since all the other speculations mentioned could be quite noticeable or would give obvious signs such as oil everywhere, or lots of blue smoke out the tailpipe, that the seals are the culprit.

Just curious, you guys with 2.3s burning lots of oil, ever get your valves adjusted?


_3

No it wasn't. Thanks for mentioning it, going to read up on that.