M57/N57

[Belle427]

Is there an easy way to know which cars had the M57 engine fitted?
I'm specifically looking at 325d/330d from 2006 to 2010.
I saw a nice 2010 325d locally but was put off when I knew it had the N57 engine.
Reason being is I'm happy to tackle a timing chain job on an engine where its at the front but not the back!
I understand at 100k miles they can be a concern.
Alternatively as I don't really need a diesel is the 325 petrol variant worth considering?
Problem with the petrol is the increased fuel consumption which is a slight consideration but not a deal breaker.

[d_a_n1979]

Completely different engine covers..

Look on Google Images and you'll see the covers and the difference

But if you get the VIN of the motor you'll also be able to decode that and see the full specs...

[sam.rog]

I wouldn’t be concerned about m57 vs n57. If the car has been well serviced it should be fine.

The n57 is the better engine imo. It’s an alloy block compared with the m57 pig iron. The N57 is much better on fuel, no swirl flap issue, thermostats don’t need replacing every service, glow plug sensors are not a serviceable item and the air filter is no a pita to change.

They both have their pros and cons but id pick the N57 every time. Mines on 94k and not a hint of timing chain rattle.

[tgr]

If you're not even decided on petrol v diesel it depends on your mileage and the type of journeys. Short journeys low miles get petrol

[d_a_n1979]

tgr said:

If you're not even decided on petrol v diesel it depends on your mileage and the type of journeys. Short journeys low miles get petrol

This is why I sold my previous F01 730D

Fantastic car, but only covering c4k Miles a year will not do it any good at all...

I do miss it, but it had to go unfortunately

[Belle427]

About 8 k mileage a year for me but just fancied experiencing the effortless torque of those engines.
I'm guessing it's engine out to do a chain on the N57?

[andrebar]

On the 325d I think the last M57 engined cars came with 197bhp vs 204bhp for the N57. There’s a similar differential with the 330d but I don’t recall the numbers. It won’t be 100% reliable but checking these figures in Autotrader ads is one way of predicting which engine you are going to end up looking at.

[d_a_n1979]

Belle427 said:

About 8 k mileage a year for me but just fancied experiencing the effortless torque of those engines.
I'm guessing it's engine out to do a chain on the N57?

Unless you're doing c20k Miles and more a year, stick with petrol IMO

Low miles aren't good for a diesel and they cost a lot more to fix compared to petrol engines..

Always worth bearing in mind IMO

[Belle427]

d_a_n1979 said:

Belle427 said:

About 8 k mileage a year for me but just fancied experiencing the effortless torque of those engines.
I'm guessing it's engine out to do a chain on the N57?

Unless you're doing c20k Miles and more a year, stick with petrol IMO

Low miles aren't good for a diesel and they cost a lot more to fix compared to petrol engines..

Always worth bearing in mind IMO

I do agree I just find the petrol engines in these cars a bit lacking unless your full on M car.

[Touring442]

sam.rog said:

I wouldn’t be concerned about m57 vs n57. If the car has been well serviced it should be fine.

The n57 is the better engine imo. It’s an alloy block compared with the m57 pig iron. The N57 is much better on fuel, no swirl flap issue, thermostats don’t need replacing every service, glow plug sensors are not a serviceable item and the air filter is no a pita to change.

They both have their pros and cons but id pick the N57 every time. Mines on 94k and not a hint of timing chain rattle.

Late M57's such as the E90 325d 3.0 are alloy block. Whilst chain breakage is not unknown, it's very rare. They are a very strong, over engineered lump capable of 300k.

N57's: chains are often on borrowed time by 130k, glow plugs (which do fail) are guaranteed to snap off in the head if you even try to remove them and swirl flaps are most certainly an issue although not as common as the M57 - itself nowhere near as common as you'd think. N47/57 flaps are on a skewer, kebab style and they can jam up and break the shaft. EGR faults are notorious of course.

Then N57 is alright as a single turbo provided they've had plenty of oil changes but twin turbo ones - and hard driven single turbo cars - are well known for crank main bearing failure.

But, when working and religiously maintained they are a superb thing. BMW designed it to be a better engine than the old one of course. They just aren't as tolerant of neglect and particularly long service intervals.

325i's of that age have very expensive and hard to resolve injector issues.

I would look for a late, nice mileage 325d M57, 2009 ish LCI.

[helix402]

As above the M57 is the more reliable engine. There is a reason some constabularies have banned officers driving anything with an N57. Later M57s also have an alloy block if what material the block is made of is a concern for you.

[4004]

Get the engine code from the VIN, or get the block number if you want to be sure.
306D3 isn't bad, but with an alu block and (potentially) piezo injectors, why not just go for the more modern DDE and everything else in the N57?

If you really want that diesel torque (and not eg EV torque), go for it, just don't expect to get interstellar mileage and intergalactic service intervals. I ran both M57 and N57 with <3k annual mileage, without issues

[Belle427]

Thanks all, I think I’m going to forget about them for now as most are at 100k miles and above so maybe where the problems will start to occur if they are going to.

[Sim89]

Touring442 said:

sam.rog said:

I wouldn’t be concerned about m57 vs n57. If the car has been well serviced it should be fine.

The n57 is the better engine imo. It’s an alloy block compared with the m57 pig iron. The N57 is much better on fuel, no swirl flap issue, thermostats don’t need replacing every service, glow plug sensors are not a serviceable item and the air filter is no a pita to change.

They both have their pros and cons but id pick the N57 every time. Mines on 94k and not a hint of timing chain rattle.

Late M57's such as the E90 325d 3.0 are alloy block. Whilst chain breakage is not unknown, it's very rare. They are a very strong, over engineered lump capable of 300k.

N57's: chains are often on borrowed time by 130k, glow plugs (which do fail) are guaranteed to snap off in the head if you even try to remove them and swirl flaps are most certainly an issue although not as common as the M57 - itself nowhere near as common as you'd think. N47/57 flaps are on a skewer, kebab style and they can jam up and break the shaft. EGR faults are notorious of course.

Then N57 is alright as a single turbo provided they've had plenty of oil changes but twin turbo ones - and hard driven single turbo cars - are well known for crank main bearing failure.

But, when working and religiously maintained they are a superb thing. BMW designed it to be a better engine than the old one of course. They just aren't as tolerant of neglect and particularly long service intervals.

325i's of that age have very expensive and hard to resolve injector issues.

I would look for a late, nice mileage 325d M57, 2009 ish LCI.

This is more or less a good summary, with the exception of the glow plugs issue. I replaced mine preventatively on MY14 F31 330d without issue at 85k. It's actually easier than M57 as you don't need to remove the inlet manifold, if you have the correct tools. Care must be taken of course (hot engine, penetrating fluid a few days before and prior to removal), but mine came out without any hint of snapping. So don't let that put you off.

My N57 is on 95k now, serviced every 10k, warmed up and down correctly, EGR blanked and mapped out correctly and thankfully, so far, no major issues.

Maintenance is everything, especially for N57.