2.5 vs 2.3 engine

[sfbazz]

Hey guys

I know that a good bunch of the 2004 through 2009 2.3 litre engines had oil consumption issues including my 06. How do the 2nd generation and newer 2.5 litre engines compare? Looking towards getting a 2012 or newer 2.5 and wondering if they have the same issues the 2.3s had. Don't want a repeat of same headaches.

[Canadianbacon]

2010 2.5 here one of strongest engines, never seen anyone have a issue with there 2.5 yet

[Mr Wilson]

There's two or three users who have the swap. Think the last one used a 2.5 out of a Ford Fusion.

[nepal1344]

I just finished my 2.5 swap into my 08 sedan. Great motor. Mine still needs some tuning but it's great.

[sfbazz]

Sorry what I meant to say was how does the 2.5 engine in the newer cars compare to the old 2.3 as I am looking to buy a 2012 or 2013 complete not do an engine swap. I'm asking if the 2.5s are plagued with the same oil burning/engine failures as my 06 seems to be slowly succumbingi to so if I am to buy a new car, would I be ok to buy a newer 3 with a 2.5. I don't want to have to look for a new car again after only 6 years and less than 200k on it. Don't want to have to check the oil levels weekly hoping I don't have to add oil again. Want to see if people with the 2.5 are experiencing any oil consumption issues at say 100k when i started noticing things on my 2.3.

[Milan96]

137,000 on my 2010 2.5, doesn't burn a drop of oil between changes. Still pulls really well, smooth as butter. You'll be surprised at how quick the 2.5 is. I drag raced a friend of mine in his 09 G37S and it was actually really close, the 3 times we did it. The look on his face when a mazda 3 was able to keep up with a g37s was priceless. You can't go wrong with the 2.5

[Reddie1337]

I will have to play devil's advocate and say that my 2012 2.5L GT while driving normally (no hard driving, big snow storm) decided to make piston and plug collide. Not a good day if I say so myself.

Edit to add that it only had 23807km on it when it blew.

[Squisher]

Piston and plug? So what exactly happened?

[Reddie1337]

Piston and plug? So what exactly happened?

I never actually took it apart, but it seems like the piston travelled too high, and the top of the piston made contact with the plug. It broke the plug, and I put another plug in and it just did the same thing. I would assume the bearing in the bottom let go, letting the piston travel too high.

Like I said, I never actually took it apart yet, I just swapped the engine.

[m_bisson]

I never actually took it apart, but it seems like the piston travelled too high, and the top of the piston made contact with the plug. It broke the plug, and I put another plug in and it just did the same thing. I would assume the bearing in the bottom let go, letting the piston travel too high.

Like I said, I never actually took it apart yet, I just swapped the engine.

Wouldn't that be under warranty?

[Reddie1337]

Wouldn't that be under warranty?

Without an accident on the history, it would have been, but since it was in an accident, no.

[Jackal]

Sorry what I meant to say was how does the 2.5 engine in the newer cars compare to the old 2.3 as I am looking to buy a 2012 or 2013 complete not do an engine swap. I'm asking if the 2.5s are plagued with the same oil burning/engine failures as my 06 seems to be slowly succumbingi to so if I am to buy a new car, would I be ok to buy a newer 3 with a 2.5. I don't want to have to look for a new car again after only 6 years and less than 200k on it. Don't want to have to check the oil levels weekly hoping I don't have to add oil again. Want to see if people with the 2.5 are experiencing any oil consumption issues at say 100k when i started noticing things on my 2.3.

2010 2.5 GT with 92,000km. No oil burning issues. No engine problems whatsoever. It runs great. I haven't reached the 100k number that you mentioned. Maybe there are others on here with a higher mileage.

[Kiyomi]

ive got 103,000kms. and the engine has been beat on its whole life, no issues.

[staax]

I opted for the 2.0 (non sky) since it's been around for a while compared to the 2.5.

With all the 2.5's getting higher in mileage and I haven't heard anything that would indicate its an unreliable motor.

I would personally prefer the 2.5 over the 2.3 for sure.

[DualSoul]

2.5L with ~130,000KM. No issues, synthetic oil since first oil change but no other work. Probably due for spark plugs. Typically don't beat on the car too much but when I do it doesn't complain.

[slam525i]

Also a 2.5L with ~130k. I haven't even been using synthetic. No work at all related to the engine. No throttle body cleaning, or injector cleaning or anything. Not even spark plugs.

Occasionally, I'll have to crank extra-long on a warm-start, but no other issues. It's a manual so I tend to rev-match down-shift right to the redline, and it doesn't seem to affect the car at all.

[sarujo]

sparkplug intervals are 120k...both of you guys are well overdue...

[slam525i]

sarujo I just looked and you're right... and curious why I hadn't done them yet, I also found out my car has less mileage than I thought it did. (I'm still under 120.) How embarrassing.

[Milan96]

Not to worry if you're over 120k and you haven't changed plugs. Iridium plugs are known to go much longer than 120k. Change them when you can, but your engine isn't going to blow up if you're 10-20k overdue

[js593]

almost 70K, love it. no major issues.

[sarujo]

Not to worry if you're over 120k and you haven't changed plugs. Iridium plugs are known to go much longer than 120k. Change them when you can, but your engine isn't going to blow up if you're 10-20k overdue

It's not so much can they go longer but the potential for seizing when in the block for so long...yes, it won't blow up the motor but you could be in for nasty surprises if one/some should seize. I would put replacement on the priority list.

[js593]

Are the Mz3 motors prone to this sarujo ? I haven't heard of this happening locally, and haven't seen much of it (if any at all) around here.

[Zuluwun]

I've heard of that sort of thing happening although I don't remember hearing about a case where it couldn't be moved with some persuasion.

Still, there's no real reason to not follow the interval. Especially for something as inexpensive (and as useful to your engine) as spark plugs.

[a_ahmed]

I blew up two 2.3 engines, the car has been a money pit ending up costing me more in it's lifetime than my track car which proved more reliable than this car which was meant to be a daily.

I am now on a 2.5 from a 2010 fusion I was the first to do the swap here in Canada. Worth every penny. Engine noticeably makes more torque/power and from a lower rev point. Car would pull/accelerate harder from higher gears than it previously did (couldn't).

So far it has been good, I do oil changes every 2-3k with 5w30 amsoil synthetic. During winter I used 0w30 as we had some pretty crazy -20 and colder weather here in Ontario. The 0w30 made it run great in winter. Used generic oil filters all until now.

The only issue is I could make more power if I could have used the 2.5 intake, but for whatever reason it didn't work... so I have the 2.3 intake instead... no ECU tuning either. I have cold air intake, exhaust manifold and catback exhaust (mazdaspeed accesory). Car is not loud and sounds great! The 2.3 sounded obnoxiously louder than the 2.5, the 2.5 just sounds rumbly and deeper but throaty.

[a_ahmed]

Oh yeah, miata guys swap to 2.5 engines... and they swear by them. They also piss on 2.3 blocks being unreliable. One guy said he had a full garage of them all blown. All dirty oil burners.

The 2.0 is also a reliable engine, but obviously less displacement.

The 2.3 I stand by what I said 2-3 years ago is garbage and I wasn't the only one having these issues. Bunch of fanboys telling me "its only you" but then I browsed around and consulted with others and looked at consumer reports... it's a bad engine. Maybe great for grandma commuters, but anything but. In fact some of the consumer reports I read amusingly cited grandmas driving the cars and doing regular oil changes and the engines going once they get to 100-120k mark.

The 2.5 is overall a better engine in every ways, the bottom end and the top end.. plus the bigger displacement.

[MAZDArati]

Depending how you take care of your car they can treat you well . Dont run around with dirty injectors and pump shitty gas into your car. My 2.3 has 170k on it , i pump royal purp or motul into it 4000k , i have a bunch of mods that put alot of stress on it . It could be a matter of time untill it blows but shes running mint and fast for now.